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Diffstat (limited to 'ext/ffi_c/libffi/src/dlmalloc.c')
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| -rw-r--r-- | ext/ffi_c/libffi/src/dlmalloc.c | 5161 |
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diff --git a/ext/ffi_c/libffi b/ext/ffi_c/libffi new file mode 160000 +Subproject c0cc9f1df9fd4c5e758470f05d0e48123f0638a diff --git a/ext/ffi_c/libffi/src/dlmalloc.c b/ext/ffi_c/libffi/src/dlmalloc.c deleted file mode 100644 index 5c9f9c2..0000000 --- a/ext/ffi_c/libffi/src/dlmalloc.c +++ /dev/null @@ -1,5161 +0,0 @@ -/* - This is a version (aka dlmalloc) of malloc/free/realloc written by - Doug Lea and released to the public domain, as explained at - http://creativecommons.org/licenses/publicdomain. Send questions, - comments, complaints, performance data, etc to dl@cs.oswego.edu - -* Version 2.8.3 Thu Sep 22 11:16:15 2005 Doug Lea (dl at gee) - - Note: There may be an updated version of this malloc obtainable at - ftp://gee.cs.oswego.edu/pub/misc/malloc.c - Check before installing! - -* Quickstart - - This library is all in one file to simplify the most common usage: - ftp it, compile it (-O3), and link it into another program. All of - the compile-time options default to reasonable values for use on - most platforms. You might later want to step through various - compile-time and dynamic tuning options. - - For convenience, an include file for code using this malloc is at: - ftp://gee.cs.oswego.edu/pub/misc/malloc-2.8.3.h - You don't really need this .h file unless you call functions not - defined in your system include files. The .h file contains only the - excerpts from this file needed for using this malloc on ANSI C/C++ - systems, so long as you haven't changed compile-time options about - naming and tuning parameters. If you do, then you can create your - own malloc.h that does include all settings by cutting at the point - indicated below. Note that you may already by default be using a C - library containing a malloc that is based on some version of this - malloc (for example in linux). You might still want to use the one - in this file to customize settings or to avoid overheads associated - with library versions. - -* Vital statistics: - - Supported pointer/size_t representation: 4 or 8 bytes - size_t MUST be an unsigned type of the same width as - pointers. (If you are using an ancient system that declares - size_t as a signed type, or need it to be a different width - than pointers, you can use a previous release of this malloc - (e.g. 2.7.2) supporting these.) - - Alignment: 8 bytes (default) - This suffices for nearly all current machines and C compilers. - However, you can define MALLOC_ALIGNMENT to be wider than this - if necessary (up to 128bytes), at the expense of using more space. - - Minimum overhead per allocated chunk: 4 or 8 bytes (if 4byte sizes) - 8 or 16 bytes (if 8byte sizes) - Each malloced chunk has a hidden word of overhead holding size - and status information, and additional cross-check word - if FOOTERS is defined. - - Minimum allocated size: 4-byte ptrs: 16 bytes (including overhead) - 8-byte ptrs: 32 bytes (including overhead) - - Even a request for zero bytes (i.e., malloc(0)) returns a - pointer to something of the minimum allocatable size. - The maximum overhead wastage (i.e., number of extra bytes - allocated than were requested in malloc) is less than or equal - to the minimum size, except for requests >= mmap_threshold that - are serviced via mmap(), where the worst case wastage is about - 32 bytes plus the remainder from a system page (the minimal - mmap unit); typically 4096 or 8192 bytes. - - Security: static-safe; optionally more or less - The "security" of malloc refers to the ability of malicious - code to accentuate the effects of errors (for example, freeing - space that is not currently malloc'ed or overwriting past the - ends of chunks) in code that calls malloc. This malloc - guarantees not to modify any memory locations below the base of - heap, i.e., static variables, even in the presence of usage - errors. The routines additionally detect most improper frees - and reallocs. All this holds as long as the static bookkeeping - for malloc itself is not corrupted by some other means. This - is only one aspect of security -- these checks do not, and - cannot, detect all possible programming errors. - - If FOOTERS is defined nonzero, then each allocated chunk - carries an additional check word to verify that it was malloced - from its space. These check words are the same within each - execution of a program using malloc, but differ across - executions, so externally crafted fake chunks cannot be - freed. This improves security by rejecting frees/reallocs that - could corrupt heap memory, in addition to the checks preventing - writes to statics that are always on. This may further improve - security at the expense of time and space overhead. (Note that - FOOTERS may also be worth using with MSPACES.) - - By default detected errors cause the program to abort (calling - "abort()"). You can override this to instead proceed past - errors by defining PROCEED_ON_ERROR. In this case, a bad free - has no effect, and a malloc that encounters a bad address - caused by user overwrites will ignore the bad address by - dropping pointers and indices to all known memory. This may - be appropriate for programs that should continue if at all - possible in the face of programming errors, although they may - run out of memory because dropped memory is never reclaimed. - - If you don't like either of these options, you can define - CORRUPTION_ERROR_ACTION and USAGE_ERROR_ACTION to do anything - else. And if if you are sure that your program using malloc has - no errors or vulnerabilities, you can define INSECURE to 1, - which might (or might not) provide a small performance improvement. - - Thread-safety: NOT thread-safe unless USE_LOCKS defined - When USE_LOCKS is defined, each public call to malloc, free, - etc is surrounded with either a pthread mutex or a win32 - spinlock (depending on WIN32). This is not especially fast, and - can be a major bottleneck. It is designed only to provide - minimal protection in concurrent environments, and to provide a - basis for extensions. If you are using malloc in a concurrent - program, consider instead using ptmalloc, which is derived from - a version of this malloc. (See http://www.malloc.de). - - System requirements: Any combination of MORECORE and/or MMAP/MUNMAP - This malloc can use unix sbrk or any emulation (invoked using - the CALL_MORECORE macro) and/or mmap/munmap or any emulation - (invoked using CALL_MMAP/CALL_MUNMAP) to get and release system - memory. On most unix systems, it tends to work best if both - MORECORE and MMAP are enabled. On Win32, it uses emulations - based on VirtualAlloc. It also uses common C library functions - like memset. - - Compliance: I believe it is compliant with the Single Unix Specification - (See http://www.unix.org). Also SVID/XPG, ANSI C, and probably - others as well. - -* Overview of algorithms - - This is not the fastest, most space-conserving, most portable, or - most tunable malloc ever written. However it is among the fastest - while also being among the most space-conserving, portable and - tunable. Consistent balance across these factors results in a good - general-purpose allocator for malloc-intensive programs. - - In most ways, this malloc is a best-fit allocator. Generally, it - chooses the best-fitting existing chunk for a request, with ties - broken in approximately least-recently-used order. (This strategy - normally maintains low fragmentation.) However, for requests less - than 256bytes, it deviates from best-fit when there is not an - exactly fitting available chunk by preferring to use space adjacent - to that used for the previous small request, as well as by breaking - ties in approximately most-recently-used order. (These enhance - locality of series of small allocations.) And for very large requests - (>= 256Kb by default), it relies on system memory mapping - facilities, if supported. (This helps avoid carrying around and - possibly fragmenting memory used only for large chunks.) - - All operations (except malloc_stats and mallinfo) have execution - times that are bounded by a constant factor of the number of bits in - a size_t, not counting any clearing in calloc or copying in realloc, - or actions surrounding MORECORE and MMAP that have times - proportional to the number of non-contiguous regions returned by - system allocation routines, which is often just 1. - - The implementation is not very modular and seriously overuses - macros. Perhaps someday all C compilers will do as good a job - inlining modular code as can now be done by brute-force expansion, - but now, enough of them seem not to. - - Some compilers issue a lot of warnings about code that is - dead/unreachable only on some platforms, and also about intentional - uses of negation on unsigned types. All known cases of each can be - ignored. - - For a longer but out of date high-level description, see - http://gee.cs.oswego.edu/dl/html/malloc.html - -* MSPACES - If MSPACES is defined, then in addition to malloc, free, etc., - this file also defines mspace_malloc, mspace_free, etc. These - are versions of malloc routines that take an "mspace" argument - obtained using create_mspace, to control all internal bookkeeping. - If ONLY_MSPACES is defined, only these versions are compiled. - So if you would like to use this allocator for only some allocations, - and your system malloc for others, you can compile with - ONLY_MSPACES and then do something like... - static mspace mymspace = create_mspace(0,0); // for example - #define mymalloc(bytes) mspace_malloc(mymspace, bytes) - - (Note: If you only need one instance of an mspace, you can instead - use "USE_DL_PREFIX" to relabel the global malloc.) - - You can similarly create thread-local allocators by storing - mspaces as thread-locals. For example: - static __thread mspace tlms = 0; - void* tlmalloc(size_t bytes) { - if (tlms == 0) tlms = create_mspace(0, 0); - return mspace_malloc(tlms, bytes); - } - void tlfree(void* mem) { mspace_free(tlms, mem); } - - Unless FOOTERS is defined, each mspace is completely independent. - You cannot allocate from one and free to another (although - conformance is only weakly checked, so usage errors are not always - caught). If FOOTERS is defined, then each chunk carries around a tag - indicating its originating mspace, and frees are directed to their - originating spaces. - - ------------------------- Compile-time options --------------------------- - -Be careful in setting #define values for numerical constants of type -size_t. On some systems, literal values are not automatically extended -to size_t precision unless they are explicitly casted. - -WIN32 default: defined if _WIN32 defined - Defining WIN32 sets up defaults for MS environment and compilers. - Otherwise defaults are for unix. - -MALLOC_ALIGNMENT default: (size_t)8 - Controls the minimum alignment for malloc'ed chunks. It must be a - power of two and at least 8, even on machines for which smaller - alignments would suffice. It may be defined as larger than this - though. Note however that code and data structures are optimized for - the case of 8-byte alignment. - -MSPACES default: 0 (false) - If true, compile in support for independent allocation spaces. - This is only supported if HAVE_MMAP is true. - -ONLY_MSPACES default: 0 (false) - If true, only compile in mspace versions, not regular versions. - -USE_LOCKS default: 0 (false) - Causes each call to each public routine to be surrounded with - pthread or WIN32 mutex lock/unlock. (If set true, this can be - overridden on a per-mspace basis for mspace versions.) - -FOOTERS default: 0 - If true, provide extra checking and dispatching by placing - information in the footers of allocated chunks. This adds - space and time overhead. - -INSECURE default: 0 - If true, omit checks for usage errors and heap space overwrites. - -USE_DL_PREFIX default: NOT defined - Causes compiler to prefix all public routines with the string 'dl'. - This can be useful when you only want to use this malloc in one part - of a program, using your regular system malloc elsewhere. - -ABORT default: defined as abort() - Defines how to abort on failed checks. On most systems, a failed - check cannot die with an "assert" or even print an informative - message, because the underlying print routines in turn call malloc, - which will fail again. Generally, the best policy is to simply call - abort(). It's not very useful to do more than this because many - errors due to overwriting will show up as address faults (null, odd - addresses etc) rather than malloc-triggered checks, so will also - abort. Also, most compilers know that abort() does not return, so - can better optimize code conditionally calling it. - -PROCEED_ON_ERROR default: defined as 0 (false) - Controls whether detected bad addresses cause them to bypassed - rather than aborting. If set, detected bad arguments to free and - realloc are ignored. And all bookkeeping information is zeroed out - upon a detected overwrite of freed heap space, thus losing the - ability to ever return it from malloc again, but enabling the - application to proceed. If PROCEED_ON_ERROR is defined, the - static variable malloc_corruption_error_count is compiled in - and can be examined to see if errors have occurred. This option - generates slower code than the default abort policy. - -DEBUG default: NOT defined - The DEBUG setting is mainly intended for people trying to modify - this code or diagnose problems when porting to new platforms. - However, it may also be able to better isolate user errors than just - using runtime checks. The assertions in the check routines spell - out in more detail the assumptions and invariants underlying the - algorithms. The checking is fairly extensive, and will slow down - execution noticeably. Calling malloc_stats or mallinfo with DEBUG - set will attempt to check every non-mmapped allocated and free chunk - in the course of computing the summaries. - -ABORT_ON_ASSERT_FAILURE default: defined as 1 (true) - Debugging assertion failures can be nearly impossible if your - version of the assert macro causes malloc to be called, which will - lead to a cascade of further failures, blowing the runtime stack. - ABORT_ON_ASSERT_FAILURE cause assertions failures to call abort(), - which will usually make debugging easier. - -MALLOC_FAILURE_ACTION default: sets errno to ENOMEM, or no-op on win32 - The action to take before "return 0" when malloc fails to be able to - return memory because there is none available. - -HAVE_MORECORE default: 1 (true) unless win32 or ONLY_MSPACES - True if this system supports sbrk or an emulation of it. - -MORECORE default: sbrk - The name of the sbrk-style system routine to call to obtain more - memory. See below for guidance on writing custom MORECORE - functions. The type of the argument to sbrk/MORECORE varies across - systems. It cannot be size_t, because it supports negative - arguments, so it is normally the signed type of the same width as - size_t (sometimes declared as "intptr_t"). It doesn't much matter - though. Internally, we only call it with arguments less than half - the max value of a size_t, which should work across all reasonable - possibilities, although sometimes generating compiler warnings. See - near the end of this file for guidelines for creating a custom - version of MORECORE. - -MORECORE_CONTIGUOUS default: 1 (true) - If true, take advantage of fact that consecutive calls to MORECORE - with positive arguments always return contiguous increasing - addresses. This is true of unix sbrk. It does not hurt too much to - set it true anyway, since malloc copes with non-contiguities. - Setting it false when definitely non-contiguous saves time - and possibly wasted space it would take to discover this though. - -MORECORE_CANNOT_TRIM default: NOT defined - True if MORECORE cannot release space back to the system when given - negative arguments. This is generally necessary only if you are - using a hand-crafted MORECORE function that cannot handle negative - arguments. - -HAVE_MMAP default: 1 (true) - True if this system supports mmap or an emulation of it. If so, and - HAVE_MORECORE is not true, MMAP is used for all system - allocation. If set and HAVE_MORECORE is true as well, MMAP is - primarily used to directly allocate very large blocks. It is also - used as a backup strategy in cases where MORECORE fails to provide - space from system. Note: A single call to MUNMAP is assumed to be - able to unmap memory that may have be allocated using multiple calls - to MMAP, so long as they are adjacent. - -HAVE_MREMAP default: 1 on linux, else 0 - If true realloc() uses mremap() to re-allocate large blocks and - extend or shrink allocation spaces. - -MMAP_CLEARS default: 1 on unix - True if mmap clears memory so calloc doesn't need to. This is true - for standard unix mmap using /dev/zero. - -USE_BUILTIN_FFS default: 0 (i.e., not used) - Causes malloc to use the builtin ffs() function to compute indices. - Some compilers may recognize and intrinsify ffs to be faster than the - supplied C version. Also, the case of x86 using gcc is special-cased - to an asm instruction, so is already as fast as it can be, and so - this setting has no effect. (On most x86s, the asm version is only - slightly faster than the C version.) - -malloc_getpagesize default: derive from system includes, or 4096. - The system page size. To the extent possible, this malloc manages - memory from the system in page-size units. This may be (and - usually is) a function rather than a constant. This is ignored - if WIN32, where page size is determined using getSystemInfo during - initialization. - -USE_DEV_RANDOM default: 0 (i.e., not used) - Causes malloc to use /dev/random to initialize secure magic seed for - stamping footers. Otherwise, the current time is used. - -NO_MALLINFO default: 0 - If defined, don't compile "mallinfo". This can be a simple way - of dealing with mismatches between system declarations and - those in this file. - -MALLINFO_FIELD_TYPE default: size_t - The type of the fields in the mallinfo struct. This was originally - defined as "int" in SVID etc, but is more usefully defined as - size_t. The value is used only if HAVE_USR_INCLUDE_MALLOC_H is not set - -REALLOC_ZERO_BYTES_FREES default: not defined - This should be set if a call to realloc with zero bytes should - be the same as a call to free. Some people think it should. Otherwise, - since this malloc returns a unique pointer for malloc(0), so does - realloc(p, 0). - -LACKS_UNISTD_H, LACKS_FCNTL_H, LACKS_SYS_PARAM_H, LACKS_SYS_MMAN_H -LACKS_STRINGS_H, LACKS_STRING_H, LACKS_SYS_TYPES_H, LACKS_ERRNO_H -LACKS_STDLIB_H default: NOT defined unless on WIN32 - Define these if your system does not have these header files. - You might need to manually insert some of the declarations they provide. - -DEFAULT_GRANULARITY default: page size if MORECORE_CONTIGUOUS, - system_info.dwAllocationGranularity in WIN32, - otherwise 64K. - Also settable using mallopt(M_GRANULARITY, x) - The unit for allocating and deallocating memory from the system. On - most systems with contiguous MORECORE, there is no reason to - make this more than a page. However, systems with MMAP tend to - either require or encourage larger granularities. You can increase - this value to prevent system allocation functions to be called so - often, especially if they are slow. The value must be at least one - page and must be a power of two. Setting to 0 causes initialization - to either page size or win32 region size. (Note: In previous - versions of malloc, the equivalent of this option was called - "TOP_PAD") - -DEFAULT_TRIM_THRESHOLD default: 2MB - Also settable using mallopt(M_TRIM_THRESHOLD, x) - The maximum amount of unused top-most memory to keep before - releasing via malloc_trim in free(). Automatic trimming is mainly - useful in long-lived programs using contiguous MORECORE. Because - trimming via sbrk can be slow on some systems, and can sometimes be - wasteful (in cases where programs immediately afterward allocate - more large chunks) the value should be high enough so that your - overall system performance would improve by releasing this much - memory. As a rough guide, you might set to a value close to the - average size of a process (program) running on your system. - Releasing this much memory would allow such a process to run in - memory. Generally, it is worth tuning trim thresholds when a - program undergoes phases where several large chunks are allocated - and released in ways that can reuse each other's storage, perhaps - mixed with phases where there are no such chunks at all. The trim - value must be greater than page size to have any useful effect. To - disable trimming completely, you can set to MAX_SIZE_T. Note that the trick - some people use of mallocing a huge space and then freeing it at - program startup, in an attempt to reserve system memory, doesn't - have the intended effect under automatic trimming, since that memory - will immediately be returned to the system. - -DEFAULT_MMAP_THRESHOLD default: 256K - Also settable using mallopt(M_MMAP_THRESHOLD, x) - The request size threshold for using MMAP to directly service a - request. Requests of at least this size that cannot be allocated - using already-existing space will be serviced via mmap. (If enough - normal freed space already exists it is used instead.) Using mmap - segregates relatively large chunks of memory so that they can be - individually obtained and released from the host system. A request - serviced through mmap is never reused by any other request (at least - not directly; the system may just so happen to remap successive - requests to the same locations). Segregating space in this way has - the benefits that: Mmapped space can always be individually released - back to the system, which helps keep the system level memory demands - of a long-lived program low. Also, mapped memory doesn't become - `locked' between other chunks, as can happen with normally allocated - chunks, which means that even trimming via malloc_trim would not - release them. However, it has the disadvantage that the space - cannot be reclaimed, consolidated, and then used to service later - requests, as happens with normal chunks. The advantages of mmap - nearly always outweigh disadvantages for "large" chunks, but the - value of "large" may vary across systems. The default is an - empirically derived value that works well in most systems. You can - disable mmap by setting to MAX_SIZE_T. - -*/ - -#ifndef WIN32 -#ifdef _WIN32 -#define WIN32 1 -#endif /* _WIN32 */ -#endif /* WIN32 */ -#ifdef WIN32 -#define WIN32_LEAN_AND_MEAN -#include <windows.h> -#define HAVE_MMAP 1 -#define HAVE_MORECORE 0 -#define LACKS_UNISTD_H -#define LACKS_SYS_PARAM_H -#define LACKS_SYS_MMAN_H -#define LACKS_STRING_H -#define LACKS_STRINGS_H -#define LACKS_SYS_TYPES_H -#define LACKS_ERRNO_H -#define MALLOC_FAILURE_ACTION -#define MMAP_CLEARS 0 /* WINCE and some others apparently don't clear */ -#endif /* WIN32 */ - -#ifdef __OS2__ -#define INCL_DOS -#include <os2.h> -#define HAVE_MMAP 1 -#define HAVE_MORECORE 0 -#define LACKS_SYS_MMAN_H -#endif /* __OS2__ */ - -#if defined(DARWIN) || defined(_DARWIN) -/* Mac OSX docs advise not to use sbrk; it seems better to use mmap */ -#ifndef HAVE_MORECORE -#define HAVE_MORECORE 0 -#define HAVE_MMAP 1 -#endif /* HAVE_MORECORE */ -#endif /* DARWIN */ - -#ifndef LACKS_SYS_TYPES_H -#include <sys/types.h> /* For size_t */ -#endif /* LACKS_SYS_TYPES_H */ - -/* The maximum possible size_t value has all bits set */ -#define MAX_SIZE_T (~(size_t)0) - -#ifndef ONLY_MSPACES -#define ONLY_MSPACES 0 -#endif /* ONLY_MSPACES */ -#ifndef MSPACES -#if ONLY_MSPACES -#define MSPACES 1 -#else /* ONLY_MSPACES */ -#define MSPACES 0 -#endif /* ONLY_MSPACES */ -#endif /* MSPACES */ -#ifndef MALLOC_ALIGNMENT -#define MALLOC_ALIGNMENT ((size_t)8U) -#endif /* MALLOC_ALIGNMENT */ -#ifndef FOOTERS -#define FOOTERS 0 -#endif /* FOOTERS */ -#ifndef ABORT -#define ABORT abort() -#endif /* ABORT */ -#ifndef ABORT_ON_ASSERT_FAILURE -#define ABORT_ON_ASSERT_FAILURE 1 -#endif /* ABORT_ON_ASSERT_FAILURE */ -#ifndef PROCEED_ON_ERROR -#define PROCEED_ON_ERROR 0 -#endif /* PROCEED_ON_ERROR */ -#ifndef USE_LOCKS -#define USE_LOCKS 0 -#endif /* USE_LOCKS */ -#ifndef INSECURE -#define INSECURE 0 -#endif /* INSECURE */ -#ifndef HAVE_MMAP -#define HAVE_MMAP 1 -#endif /* HAVE_MMAP */ -#ifndef MMAP_CLEARS -#define MMAP_CLEARS 1 -#endif /* MMAP_CLEARS */ -#ifndef HAVE_MREMAP -#ifdef linux -#define HAVE_MREMAP 1 -#else /* linux */ -#define HAVE_MREMAP 0 -#endif /* linux */ -#endif /* HAVE_MREMAP */ -#ifndef MALLOC_FAILURE_ACTION -#define MALLOC_FAILURE_ACTION errno = ENOMEM; -#endif /* MALLOC_FAILURE_ACTION */ -#ifndef HAVE_MORECORE -#if ONLY_MSPACES -#define HAVE_MORECORE 0 -#else /* ONLY_MSPACES */ -#define HAVE_MORECORE 1 -#endif /* ONLY_MSPACES */ -#endif /* HAVE_MORECORE */ -#if !HAVE_MORECORE -#define MORECORE_CONTIGUOUS 0 -#else /* !HAVE_MORECORE */ -#ifndef MORECORE -#define MORECORE sbrk -#endif /* MORECORE */ -#ifndef MORECORE_CONTIGUOUS -#define MORECORE_CONTIGUOUS 1 -#endif /* MORECORE_CONTIGUOUS */ -#endif /* HAVE_MORECORE */ -#ifndef DEFAULT_GRANULARITY -#if MORECORE_CONTIGUOUS -#define DEFAULT_GRANULARITY (0) /* 0 means to compute in init_mparams */ -#else /* MORECORE_CONTIGUOUS */ -#define DEFAULT_GRANULARITY ((size_t)64U * (size_t)1024U) -#endif /* MORECORE_CONTIGUOUS */ -#endif /* DEFAULT_GRANULARITY */ -#ifndef DEFAULT_TRIM_THRESHOLD -#ifndef MORECORE_CANNOT_TRIM -#define DEFAULT_TRIM_THRESHOLD ((size_t)2U * (size_t)1024U * (size_t)1024U) -#else /* MORECORE_CANNOT_TRIM */ -#define DEFAULT_TRIM_THRESHOLD MAX_SIZE_T -#endif /* MORECORE_CANNOT_TRIM */ -#endif /* DEFAULT_TRIM_THRESHOLD */ -#ifndef DEFAULT_MMAP_THRESHOLD -#if HAVE_MMAP -#define DEFAULT_MMAP_THRESHOLD ((size_t)256U * (size_t)1024U) -#else /* HAVE_MMAP */ -#define DEFAULT_MMAP_THRESHOLD MAX_SIZE_T -#endif /* HAVE_MMAP */ -#endif /* DEFAULT_MMAP_THRESHOLD */ -#ifndef USE_BUILTIN_FFS -#define USE_BUILTIN_FFS 0 -#endif /* USE_BUILTIN_FFS */ -#ifndef USE_DEV_RANDOM -#define USE_DEV_RANDOM 0 -#endif /* USE_DEV_RANDOM */ -#ifndef NO_MALLINFO -#define NO_MALLINFO 0 -#endif /* NO_MALLINFO */ -#ifndef MALLINFO_FIELD_TYPE -#define MALLINFO_FIELD_TYPE size_t -#endif /* MALLINFO_FIELD_TYPE */ - -/* - mallopt tuning options. SVID/XPG defines four standard parameter - numbers for mallopt, normally defined in malloc.h. None of these - are used in this malloc, so setting them has no effect. But this - malloc does support the following options. -*/ - -#define M_TRIM_THRESHOLD (-1) -#define M_GRANULARITY (-2) -#define M_MMAP_THRESHOLD (-3) - -/* ------------------------ Mallinfo declarations ------------------------ */ - -#if !NO_MALLINFO -/* - This version of malloc supports the standard SVID/XPG mallinfo - routine that returns a struct containing usage properties and - statistics. It should work on any system that has a - /usr/include/malloc.h defining struct mallinfo. The main - declaration needed is the mallinfo struct that is returned (by-copy) - by mallinfo(). The malloinfo struct contains a bunch of fields that - are not even meaningful in this version of malloc. These fields are - are instead filled by mallinfo() with other numbers that might be of - interest. - - HAVE_USR_INCLUDE_MALLOC_H should be set if you have a - /usr/include/malloc.h file that includes a declaration of struct - mallinfo. If so, it is included; else a compliant version is - declared below. These must be precisely the same for mallinfo() to - work. The original SVID version of this struct, defined on most - systems with mallinfo, declares all fields as ints. But some others - define as unsigned long. If your system defines the fields using a - type of different width than listed here, you MUST #include your - system version and #define HAVE_USR_INCLUDE_MALLOC_H. -*/ - -/* #define HAVE_USR_INCLUDE_MALLOC_H */ - -#ifdef HAVE_USR_INCLUDE_MALLOC_H -#include "/usr/include/malloc.h" -#else /* HAVE_USR_INCLUDE_MALLOC_H */ - -/* HP-UX's stdlib.h redefines mallinfo unless _STRUCT_MALLINFO is defined */ -#define _STRUCT_MALLINFO - -struct mallinfo { - MALLINFO_FIELD_TYPE arena; /* non-mmapped space allocated from system */ - MALLINFO_FIELD_TYPE ordblks; /* number of free chunks */ - MALLINFO_FIELD_TYPE smblks; /* always 0 */ - MALLINFO_FIELD_TYPE hblks; /* always 0 */ - MALLINFO_FIELD_TYPE hblkhd; /* space in mmapped regions */ - MALLINFO_FIELD_TYPE usmblks; /* maximum total allocated space */ - MALLINFO_FIELD_TYPE fsmblks; /* always 0 */ - MALLINFO_FIELD_TYPE uordblks; /* total allocated space */ - MALLINFO_FIELD_TYPE fordblks; /* total free space */ - MALLINFO_FIELD_TYPE keepcost; /* releasable (via malloc_trim) space */ -}; - -#endif /* HAVE_USR_INCLUDE_MALLOC_H */ -#endif /* NO_MALLINFO */ - -#ifdef __cplusplus -extern "C" { -#endif /* __cplusplus */ - -#if !ONLY_MSPACES - -/* ------------------- Declarations of public routines ------------------- */ - -#ifndef USE_DL_PREFIX -#define dlcalloc calloc -#define dlfree free -#define dlmalloc malloc -#define dlmemalign memalign -#define dlrealloc realloc -#define dlvalloc valloc -#define dlpvalloc pvalloc -#define dlmallinfo mallinfo -#define dlmallopt mallopt -#define dlmalloc_trim malloc_trim -#define dlmalloc_stats malloc_stats -#define dlmalloc_usable_size malloc_usable_size -#define dlmalloc_footprint malloc_footprint -#define dlmalloc_max_footprint malloc_max_footprint -#define dlindependent_calloc independent_calloc -#define dlindependent_comalloc independent_comalloc -#endif /* USE_DL_PREFIX */ - - -/* - malloc(size_t n) - Returns a pointer to a newly allocated chunk of at least n bytes, or - null if no space is available, in which case errno is set to ENOMEM - on ANSI C systems. - - If n is zero, malloc returns a minimum-sized chunk. (The minimum - size is 16 bytes on most 32bit systems, and 32 bytes on 64bit - systems.) Note that size_t is an unsigned type, so calls with - arguments that would be negative if signed are interpreted as - requests for huge amounts of space, which will often fail. The - maximum supported value of n differs across systems, but is in all - cases less than the maximum representable value of a size_t. -*/ -void* dlmalloc(size_t); - -/* - free(void* p) - Releases the chunk of memory pointed to by p, that had been previously - allocated using malloc or a related routine such as realloc. - It has no effect if p is null. If p was not malloced or already - freed, free(p) will by default cause the current program to abort. -*/ -void dlfree(void*); - -/* - calloc(size_t n_elements, size_t element_size); - Returns a pointer to n_elements * element_size bytes, with all locations - set to zero. -*/ -void* dlcalloc(size_t, size_t); - -/* - realloc(void* p, size_t n) - Returns a pointer to a chunk of size n that contains the same data - as does chunk p up to the minimum of (n, p's size) bytes, or null - if no space is available. - - The returned pointer may or may not be the same as p. The algorithm - prefers extending p in most cases when possible, otherwise it - employs the equivalent of a malloc-copy-free sequence. - - If p is null, realloc is equivalent to malloc. - - If space is not available, realloc returns null, errno is set (if on - ANSI) and p is NOT freed. - - if n is for fewer bytes than already held by p, the newly unused - space is lopped off and freed if possible. realloc with a size - argument of zero (re)allocates a minimum-sized chunk. - - The old unix realloc convention of allowing the last-free'd chunk - to be used as an argument to realloc is not supported. -*/ - -void* dlrealloc(void*, size_t); - -/* - memalign(size_t alignment, size_t n); - Returns a pointer to a newly allocated chunk of n bytes, aligned - in accord with the alignment argument. - - The alignment argument should be a power of two. If the argument is - not a power of two, the nearest greater power is used. - 8-byte alignment is guaranteed by normal malloc calls, so don't - bother calling memalign with an argument of 8 or less. - - Overreliance on memalign is a sure way to fragment space. -*/ -void* dlmemalign(size_t, size_t); - -/* - valloc(size_t n); - Equivalent to memalign(pagesize, n), where pagesize is the page - size of the system. If the pagesize is unknown, 4096 is used. -*/ -void* dlvalloc(size_t); - -/* - mallopt(int parameter_number, int parameter_value) - Sets tunable parameters The format is to provide a - (parameter-number, parameter-value) pair. mallopt then sets the - corresponding parameter to the argument value if it can (i.e., so - long as the value is meaningful), and returns 1 if successful else - 0. SVID/XPG/ANSI defines four standard param numbers for mallopt, - normally defined in malloc.h. None of these are use in this malloc, - so setting them has no effect. But this malloc also supports other - options in mallopt. See below for details. Briefly, supported - parameters are as follows (listed defaults are for "typical" - configurations). - - Symbol param # default allowed param values - M_TRIM_THRESHOLD -1 2*1024*1024 any (MAX_SIZE_T disables) - M_GRANULARITY -2 page size any power of 2 >= page size - M_MMAP_THRESHOLD -3 256*1024 any (or 0 if no MMAP support) -*/ -int dlmallopt(int, int); - -/* - malloc_footprint(); - Returns the number of bytes obtained from the system. The total - number of bytes allocated by malloc, realloc etc., is less than this - value. Unlike mallinfo, this function returns only a precomputed - result, so can be called frequently to monitor memory consumption. - Even if locks are otherwise defined, this function does not use them, - so results might not be up to date. -*/ -size_t dlmalloc_footprint(void); - -/* - malloc_max_footprint(); - Returns the maximum number of bytes obtained from the system. This - value will be greater than current footprint if deallocated space - has been reclaimed by the system. The peak number of bytes allocated - by malloc, realloc etc., is less than this value. Unlike mallinfo, - this function returns only a precomputed result, so can be called - frequently to monitor memory consumption. Even if locks are - otherwise defined, this function does not use them, so results might - not be up to date. -*/ -size_t dlmalloc_max_footprint(void); - -#if !NO_MALLINFO -/* - mallinfo() - Returns (by copy) a struct containing various summary statistics: - - arena: current total non-mmapped bytes allocated from system - ordblks: the number of free chunks - smblks: always zero. - hblks: current number of mmapped regions - hblkhd: total bytes held in mmapped regions - usmblks: the maximum total allocated space. This will be greater - than current total if trimming has occurred. - fsmblks: always zero - uordblks: current total allocated space (normal or mmapped) - fordblks: total free space - keepcost: the maximum number of bytes that could ideally be released - back to system via malloc_trim. ("ideally" means that - it ignores page restrictions etc.) - - Because these fields are ints, but internal bookkeeping may - be kept as longs, the reported values may wrap around zero and - thus be inaccurate. -*/ -struct mallinfo dlmallinfo(void); -#endif /* NO_MALLINFO */ - -/* - independent_calloc(size_t n_elements, size_t element_size, void* chunks[]); - - independent_calloc is similar to calloc, but instead of returning a - single cleared space, it returns an array of pointers to n_elements - independent elements that can hold contents of size elem_size, each - of which starts out cleared, and can be independently freed, - realloc'ed etc. The elements are guaranteed to be adjacently - allocated (this is not guaranteed to occur with multiple callocs or - mallocs), which may also improve cache locality in some - applications. - - The "chunks" argument is optional (i.e., may be null, which is - probably the most typical usage). If it is null, the returned array - is itself dynamically allocated and should also be freed when it is - no longer needed. Otherwise, the chunks array must be of at least - n_elements in length. It is filled in with the pointers to the - chunks. - - In either case, independent_calloc returns this pointer array, or - null if the allocation failed. If n_elements is zero and "chunks" - is null, it returns a chunk representing an array with zero elements - (which should be freed if not wanted). - - Each element must be individually freed when it is no longer - needed. If you'd like to instead be able to free all at once, you - should instead use regular calloc and assign pointers into this - space to represent elements. (In this case though, you cannot - independently free elements.) - - independent_calloc simplifies and speeds up implementations of many - kinds of pools. It may also be useful when constructing large data - structures that initially have a fixed number of fixed-sized nodes, - but the number is not known at compile time, and some of the nodes - may later need to be freed. For example: - - struct Node { int item; struct Node* next; }; - - struct Node* build_list() { - struct Node** pool; - int n = read_number_of_nodes_needed(); - if (n <= 0) return 0; - pool = (struct Node**)(independent_calloc(n, sizeof(struct Node), 0); - if (pool == 0) die(); - // organize into a linked list... - struct Node* first = pool[0]; - for (i = 0; i < n-1; ++i) - pool[i]->next = pool[i+1]; - free(pool); // Can now free the array (or not, if it is needed later) - return first; - } -*/ -void** dlindependent_calloc(size_t, size_t, void**); - -/* - independent_comalloc(size_t n_elements, size_t sizes[], void* chunks[]); - - independent_comalloc allocates, all at once, a set of n_elements - chunks with sizes indicated in the "sizes" array. It returns - an array of pointers to these elements, each of which can be - independently freed, realloc'ed etc. The elements are guaranteed to - be adjacently allocated (this is not guaranteed to occur with - multiple callocs or mallocs), which may also improve cache locality - in some applications. - - The "chunks" argument is optional (i.e., may be null). If it is null - the returned array is itself dynamically allocated and should also - be freed when it is no longer needed. Otherwise, the chunks array - must be of at least n_elements in length. It is filled in with the - pointers to the chunks. - - In either case, independent_comalloc returns this pointer array, or - null if the allocation failed. If n_elements is zero and chunks is - null, it returns a chunk representing an array with zero elements - (which should be freed if not wanted). - - Each element must be individually freed when it is no longer - needed. If you'd like to instead be able to free all at once, you - should instead use a single regular malloc, and assign pointers at - particular offsets in the aggregate space. (In this case though, you - cannot independently free elements.) - - independent_comallac differs from independent_calloc in that each - element may have a different size, and also that it does not - automatically clear elements. - - independent_comalloc can be used to speed up allocation in cases - where several structs or objects must always be allocated at the - same time. For example: - - struct Head { ... } - struct Foot { ... } - - void send_message(char* msg) { - int msglen = strlen(msg); - size_t sizes[3] = { sizeof(struct Head), msglen, sizeof(struct Foot) }; - void* chunks[3]; - if (independent_comalloc(3, sizes, chunks) == 0) - die(); - struct Head* head = (struct Head*)(chunks[0]); - char* body = (char*)(chunks[1]); - struct Foot* foot = (struct Foot*)(chunks[2]); - // ... - } - - In general though, independent_comalloc is worth using only for - larger values of n_elements. For small values, you probably won't - detect enough difference from series of malloc calls to bother. - - Overuse of independent_comalloc can increase overall memory usage, - since it cannot reuse existing noncontiguous small chunks that - might be available for some of the elements. -*/ -void** dlindependent_comalloc(size_t, size_t*, void**); - - -/* - pvalloc(size_t n); - Equivalent to valloc(minimum-page-that-holds(n)), that is, - round up n to nearest pagesize. - */ -void* dlpvalloc(size_t); - -/* - malloc_trim(size_t pad); - - If possible, gives memory back to the system (via negative arguments - to sbrk) if there is unused memory at the `high' end of the malloc - pool or in unused MMAP segments. You can call this after freeing - large blocks of memory to potentially reduce the system-level memory - requirements of a program. However, it cannot guarantee to reduce - memory. Under some allocation patterns, some large free blocks of - memory will be locked between two used chunks, so they cannot be - given back to the system. - - The `pad' argument to malloc_trim represents the amount of free - trailing space to leave untrimmed. If this argument is zero, only - the minimum amount of memory to maintain internal data structures - will be left. Non-zero arguments can be supplied to maintain enough - trailing space to service future expected allocations without having - to re-obtain memory from the system. - - Malloc_trim returns 1 if it actually released any memory, else 0. -*/ -int dlmalloc_trim(size_t); - -/* - malloc_usable_size(void* p); - - Returns the number of bytes you can actually use in - an allocated chunk, which may be more than you requested (although - often not) due to alignment and minimum size constraints. - You can use this many bytes without worrying about - overwriting other allocated objects. This is not a particularly great - programming practice. malloc_usable_size can be more useful in - debugging and assertions, for example: - - p = malloc(n); - assert(malloc_usable_size(p) >= 256); -*/ -size_t dlmalloc_usable_size(void*); - -/* - malloc_stats(); - Prints on stderr the amount of space obtained from the system (both - via sbrk and mmap), the maximum amount (which may be more than - current if malloc_trim and/or munmap got called), and the current - number of bytes allocated via malloc (or realloc, etc) but not yet - freed. Note that this is the number of bytes allocated, not the - number requested. It will be larger than the number requested - because of alignment and bookkeeping overhead. Because it includes - alignment wastage as being in use, this figure may be greater than - zero even when no user-level chunks are allocated. - - The reported current and maximum system memory can be inaccurate if - a program makes other calls to system memory allocation functions - (normally sbrk) outside of malloc. - - malloc_stats prints only the most commonly interesting statistics. - More information can be obtained by calling mallinfo. -*/ -void dlmalloc_stats(void); - -#endif /* ONLY_MSPACES */ - -#if MSPACES - -/* - mspace is an opaque type representing an independent - region of space that supports mspace_malloc, etc. -*/ -typedef void* mspace; - -/* - create_mspace creates and returns a new independent space with the - given initial capacity, or, if 0, the default granularity size. It - returns null if there is no system memory available to create the - space. If argument locked is non-zero, the space uses a separate - lock to control access. The capacity of the space will grow - dynamically as needed to service mspace_malloc requests. You can - control the sizes of incremental increases of this space by - compiling with a different DEFAULT_GRANULARITY or dynamically - setting with mallopt(M_GRANULARITY, value). -*/ -mspace create_mspace(size_t capacity, int locked); - -/* - destroy_mspace destroys the given space, and attempts to return all - of its memory back to the system, returning the total number of - bytes freed. After destruction, the results of access to all memory - used by the space become undefined. -*/ -size_t destroy_mspace(mspace msp); - -/* - create_mspace_with_base uses the memory supplied as the initial base - of a new mspace. Part (less than 128*sizeof(size_t) bytes) of this - space is used for bookkeeping, so the capacity must be at least this - large. (Otherwise 0 is returned.) When this initial space is - exhausted, additional memory will be obtained from the system. - Destroying this space will deallocate all additionally allocated - space (if possible) but not the initial base. -*/ -mspace create_mspace_with_base(void* base, size_t capacity, int locked); - -/* - mspace_malloc behaves as malloc, but operates within - the given space. -*/ -void* mspace_malloc(mspace msp, size_t bytes); - -/* - mspace_free behaves as free, but operates within - the given space. - - If compiled with FOOTERS==1, mspace_free is not actually needed. - free may be called instead of mspace_free because freed chunks from - any space are handled by their originating spaces. -*/ -void mspace_free(mspace msp, void* mem); - -/* - mspace_realloc behaves as realloc, but operates within - the given space. - - If compiled with FOOTERS==1, mspace_realloc is not actually - needed. realloc may be called instead of mspace_realloc because - realloced chunks from any space are handled by their originating - spaces. -*/ -void* mspace_realloc(mspace msp, void* mem, size_t newsize); - -/* - mspace_calloc behaves as calloc, but operates within - the given space. -*/ -void* mspace_calloc(mspace msp, size_t n_elements, size_t elem_size); - -/* - mspace_memalign behaves as memalign, but operates within - the given space. -*/ -void* mspace_memalign(mspace msp, size_t alignment, size_t bytes); - -/* - mspace_independent_calloc behaves as independent_calloc, but - operates within the given space. -*/ -void** mspace_independent_calloc(mspace msp, size_t n_elements, - size_t elem_size, void* chunks[]); - -/* - mspace_independent_comalloc behaves as independent_comalloc, but - operates within the given space. -*/ -void** mspace_independent_comalloc(mspace msp, size_t n_elements, - size_t sizes[], void* chunks[]); - -/* - mspace_footprint() returns the number of bytes obtained from the - system for this space. -*/ -size_t mspace_footprint(mspace msp); - -/* - mspace_max_footprint() returns the peak number of bytes obtained from the - system for this space. -*/ -size_t mspace_max_footprint(mspace msp); - - -#if !NO_MALLINFO -/* - mspace_mallinfo behaves as mallinfo, but reports properties of - the given space. -*/ -struct mallinfo mspace_mallinfo(mspace msp); -#endif /* NO_MALLINFO */ - -/* - mspace_malloc_stats behaves as malloc_stats, but reports - properties of the given space. -*/ -void mspace_malloc_stats(mspace msp); - -/* - mspace_trim behaves as malloc_trim, but - operates within the given space. -*/ -int mspace_trim(mspace msp, size_t pad); - -/* - An alias for mallopt. -*/ -int mspace_mallopt(int, int); - -#endif /* MSPACES */ - -#ifdef __cplusplus -}; /* end of extern "C" */ -#endif /* __cplusplus */ - -/* - ======================================================================== - To make a fully customizable malloc.h header file, cut everything - above this line, put into file malloc.h, edit to suit, and #include it - on the next line, as well as in programs that use this malloc. - ======================================================================== -*/ - -/* #include "malloc.h" */ - -/*------------------------------ internal #includes ---------------------- */ - -#ifdef _MSC_VER -#pragma warning( disable : 4146 ) /* no "unsigned" warnings */ -#endif /* _MSC_VER */ - -#include <stdio.h> /* for printing in malloc_stats */ - -#ifndef LACKS_ERRNO_H -#include <errno.h> /* for MALLOC_FAILURE_ACTION */ -#endif /* LACKS_ERRNO_H */ -#if FOOTERS -#include <time.h> /* for magic initialization */ -#endif /* FOOTERS */ -#ifndef LACKS_STDLIB_H -#include <stdlib.h> /* for abort() */ -#endif /* LACKS_STDLIB_H */ -#ifdef DEBUG -#if ABORT_ON_ASSERT_FAILURE -#define assert(x) if(!(x)) ABORT -#else /* ABORT_ON_ASSERT_FAILURE */ -#include <assert.h> -#endif /* ABORT_ON_ASSERT_FAILURE */ -#else /* DEBUG */ -#define assert(x) -#endif /* DEBUG */ -#ifndef LACKS_STRING_H -#include <string.h> /* for memset etc */ -#endif /* LACKS_STRING_H */ -#if USE_BUILTIN_FFS -#ifndef LACKS_STRINGS_H -#include <strings.h> /* for ffs */ -#endif /* LACKS_STRINGS_H */ -#endif /* USE_BUILTIN_FFS */ -#if HAVE_MMAP -#ifndef LACKS_SYS_MMAN_H -#include <sys/mman.h> /* for mmap */ -#endif /* LACKS_SYS_MMAN_H */ -#ifndef LACKS_FCNTL_H -#include <fcntl.h> -#endif /* LACKS_FCNTL_H */ -#endif /* HAVE_MMAP */ -#if HAVE_MORECORE -#ifndef LACKS_UNISTD_H -#include <unistd.h> /* for sbrk */ -#else /* LACKS_UNISTD_H */ -#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) -extern void* sbrk(ptrdiff_t); -#endif /* FreeBSD etc */ -#endif /* LACKS_UNISTD_H */ -#endif /* HAVE_MMAP */ - -#ifndef WIN32 -#ifndef malloc_getpagesize -# ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */ -# ifndef _SC_PAGE_SIZE -# define _SC_PAGE_SIZE _SC_PAGESIZE -# endif -# endif -# ifdef _SC_PAGE_SIZE -# define malloc_getpagesize sysconf(_SC_PAGE_SIZE) -# else -# if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE) - extern size_t getpagesize(); -# define malloc_getpagesize getpagesize() -# else -# ifdef WIN32 /* use supplied emulation of getpagesize */ -# define malloc_getpagesize getpagesize() -# else -# ifndef LACKS_SYS_PARAM_H -# include <sys/param.h> -# endif -# ifdef EXEC_PAGESIZE -# define malloc_getpagesize EXEC_PAGESIZE -# else -# ifdef NBPG -# ifndef CLSIZE -# define malloc_getpagesize NBPG -# else -# define malloc_getpagesize (NBPG * CLSIZE) -# endif -# else -# ifdef NBPC -# define malloc_getpagesize NBPC -# else -# ifdef PAGESIZE -# define malloc_getpagesize PAGESIZE -# else /* just guess */ -# define malloc_getpagesize ((size_t)4096U) -# endif -# endif -# endif -# endif -# endif -# endif -# endif -#endif -#endif - -/* ------------------- size_t and alignment properties -------------------- */ - -/* The byte and bit size of a size_t */ -#define SIZE_T_SIZE (sizeof(size_t)) -#define SIZE_T_BITSIZE (sizeof(size_t) << 3) - -/* Some constants coerced to size_t */ -/* Annoying but necessary to avoid errors on some plaftorms */ -#define SIZE_T_ZERO ((size_t)0) -#define SIZE_T_ONE ((size_t)1) -#define SIZE_T_TWO ((size_t)2) -#define TWO_SIZE_T_SIZES (SIZE_T_SIZE<<1) -#define FOUR_SIZE_T_SIZES (SIZE_T_SIZE<<2) -#define SIX_SIZE_T_SIZES (FOUR_SIZE_T_SIZES+TWO_SIZE_T_SIZES) -#define HALF_MAX_SIZE_T (MAX_SIZE_T / 2U) - -/* The bit mask value corresponding to MALLOC_ALIGNMENT */ -#define CHUNK_ALIGN_MASK (MALLOC_ALIGNMENT - SIZE_T_ONE) - -/* True if address a has acceptable alignment */ -#define is_aligned(A) (((size_t)((A)) & (CHUNK_ALIGN_MASK)) == 0) - -/* the number of bytes to offset an address to align it */ -#define align_offset(A)\ - ((((size_t)(A) & CHUNK_ALIGN_MASK) == 0)? 0 :\ - ((MALLOC_ALIGNMENT - ((size_t)(A) & CHUNK_ALIGN_MASK)) & CHUNK_ALIGN_MASK)) - -/* -------------------------- MMAP preliminaries ------------------------- */ - -/* - If HAVE_MORECORE or HAVE_MMAP are false, we just define calls and - checks to fail so compiler optimizer can delete code rather than - using so many "#if"s. -*/ - - -/* MORECORE and MMAP must return MFAIL on failure */ -#define MFAIL ((void*)(MAX_SIZE_T)) -#define CMFAIL ((char*)(MFAIL)) /* defined for convenience */ - -#if !HAVE_MMAP -#define IS_MMAPPED_BIT (SIZE_T_ZERO) -#define USE_MMAP_BIT (SIZE_T_ZERO) -#define CALL_MMAP(s) MFAIL -#define CALL_MUNMAP(a, s) (-1) -#define DIRECT_MMAP(s) MFAIL - -#else /* HAVE_MMAP */ -#define IS_MMAPPED_BIT (SIZE_T_ONE) -#define USE_MMAP_BIT (SIZE_T_ONE) - -#if !defined(WIN32) && !defined (__OS2__) -#define CALL_MUNMAP(a, s) munmap((a), (s)) -#define MMAP_PROT (PROT_READ|PROT_WRITE) -#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) -#define MAP_ANONYMOUS MAP_ANON -#endif /* MAP_ANON */ -#ifdef MAP_ANONYMOUS -#define MMAP_FLAGS (MAP_PRIVATE|MAP_ANONYMOUS) -#define CALL_MMAP(s) mmap(0, (s), MMAP_PROT, MMAP_FLAGS, -1, 0) -#else /* MAP_ANONYMOUS */ -/* - Nearly all versions of mmap support MAP_ANONYMOUS, so the following - is unlikely to be needed, but is supplied just in case. -*/ -#define MMAP_FLAGS (MAP_PRIVATE) -static int dev_zero_fd = -1; /* Cached file descriptor for /dev/zero. */ -#define CALL_MMAP(s) ((dev_zero_fd < 0) ? \ - (dev_zero_fd = open("/dev/zero", O_RDWR), \ - mmap(0, (s), MMAP_PROT, MMAP_FLAGS, dev_zero_fd, 0)) : \ - mmap(0, (s), MMAP_PROT, MMAP_FLAGS, dev_zero_fd, 0)) -#endif /* MAP_ANONYMOUS */ - -#define DIRECT_MMAP(s) CALL_MMAP(s) - -#elif defined(__OS2__) - -/* OS/2 MMAP via DosAllocMem */ -static void* os2mmap(size_t size) { - void* ptr; - if (DosAllocMem(&ptr, size, OBJ_ANY|PAG_COMMIT|PAG_READ|PAG_WRITE) && - DosAllocMem(&ptr, size, PAG_COMMIT|PAG_READ|PAG_WRITE)) - return MFAIL; - return ptr; -} - -#define os2direct_mmap(n) os2mmap(n) - -/* This function supports releasing coalesed segments */ -static int os2munmap(void* ptr, size_t size) { - while (size) { - ULONG ulSize = size; - ULONG ulFlags = 0; - if (DosQueryMem(ptr, &ulSize, &ulFlags) != 0) - return -1; - if ((ulFlags & PAG_BASE) == 0 ||(ulFlags & PAG_COMMIT) == 0 || - ulSize > size) - return -1; - if (DosFreeMem(ptr) != 0) - return -1; - ptr = ( void * ) ( ( char * ) ptr + ulSize ); - size -= ulSize; - } - return 0; -} - -#define CALL_MMAP(s) os2mmap(s) -#define CALL_MUNMAP(a, s) os2munmap((a), (s)) -#define DIRECT_MMAP(s) os2direct_mmap(s) - -#else /* WIN32 */ - -/* Win32 MMAP via VirtualAlloc */ -static void* win32mmap(size_t size) { - void* ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT, PAGE_EXECUTE_READWRITE); - return (ptr != 0)? ptr: MFAIL; -} - -/* For direct MMAP, use MEM_TOP_DOWN to minimize interference */ -static void* win32direct_mmap(size_t size) { - void* ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT|MEM_TOP_DOWN, - PAGE_EXECUTE_READWRITE); - return (ptr != 0)? ptr: MFAIL; -} - -/* This function supports releasing coalesed segments */ -static int win32munmap(void* ptr, size_t size) { - MEMORY_BASIC_INFORMATION minfo; - char* cptr = ptr; - while (size) { - if (VirtualQuery(cptr, &minfo, sizeof(minfo)) == 0) - return -1; - if (minfo.BaseAddress != cptr || minfo.AllocationBase != cptr || - minfo.State != MEM_COMMIT || minfo.RegionSize > size) - return -1; - if (VirtualFree(cptr, 0, MEM_RELEASE) == 0) - return -1; - cptr += minfo.RegionSize; - size -= minfo.RegionSize; - } - return 0; -} - -#define CALL_MMAP(s) win32mmap(s) -#define CALL_MUNMAP(a, s) win32munmap((a), (s)) -#define DIRECT_MMAP(s) win32direct_mmap(s) -#endif /* WIN32 */ -#endif /* HAVE_MMAP */ - -#if HAVE_MMAP && HAVE_MREMAP -#define CALL_MREMAP(addr, osz, nsz, mv) mremap((addr), (osz), (nsz), (mv)) -#else /* HAVE_MMAP && HAVE_MREMAP */ -#define CALL_MREMAP(addr, osz, nsz, mv) MFAIL -#endif /* HAVE_MMAP && HAVE_MREMAP */ - -#if HAVE_MORECORE -#define CALL_MORECORE(S) MORECORE(S) -#else /* HAVE_MORECORE */ -#define CALL_MORECORE(S) MFAIL -#endif /* HAVE_MORECORE */ - -/* mstate bit set if continguous morecore disabled or failed */ -#define USE_NONCONTIGUOUS_BIT (4U) - -/* segment bit set in create_mspace_with_base */ -#define EXTERN_BIT (8U) - - -/* --------------------------- Lock preliminaries ------------------------ */ - -#if USE_LOCKS - -/* - When locks are defined, there are up to two global locks: - - * If HAVE_MORECORE, morecore_mutex protects sequences of calls to - MORECORE. In many cases sys_alloc requires two calls, that should - not be interleaved with calls by other threads. This does not - protect against direct calls to MORECORE by other threads not - using this lock, so there is still code to cope the best we can on - interference. - - * magic_init_mutex ensures that mparams.magic and other - unique mparams values are initialized only once. -*/ - -#if !defined(WIN32) && !defined(__OS2__) -/* By default use posix locks */ -#include <pthread.h> -#define MLOCK_T pthread_mutex_t -#define INITIAL_LOCK(l) pthread_mutex_init(l, NULL) -#define ACQUIRE_LOCK(l) pthread_mutex_lock(l) -#define RELEASE_LOCK(l) pthread_mutex_unlock(l) - -#if HAVE_MORECORE -static MLOCK_T morecore_mutex = PTHREAD_MUTEX_INITIALIZER; -#endif /* HAVE_MORECORE */ - -static MLOCK_T magic_init_mutex = PTHREAD_MUTEX_INITIALIZER; - -#elif defined(__OS2__) -#define MLOCK_T HMTX -#define INITIAL_LOCK(l) DosCreateMutexSem(0, l, 0, FALSE) -#define ACQUIRE_LOCK(l) DosRequestMutexSem(*l, SEM_INDEFINITE_WAIT) -#define RELEASE_LOCK(l) DosReleaseMutexSem(*l) -#if HAVE_MORECORE -static MLOCK_T morecore_mutex; -#endif /* HAVE_MORECORE */ -static MLOCK_T magic_init_mutex; - -#else /* WIN32 */ -/* - Because lock-protected regions have bounded times, and there - are no recursive lock calls, we can use simple spinlocks. -*/ - -#define MLOCK_T long -static int win32_acquire_lock (MLOCK_T *sl) { - for (;;) { -#ifdef InterlockedCompareExchangePointer - if (!InterlockedCompareExchange(sl, 1, 0)) - return 0; -#else /* Use older void* version */ - if (!InterlockedCompareExchange((void**)sl, (void*)1, (void*)0)) - return 0; -#endif /* InterlockedCompareExchangePointer */ - Sleep (0); - } -} - -static void win32_release_lock (MLOCK_T *sl) { - InterlockedExchange (sl, 0); -} - -#define INITIAL_LOCK(l) *(l)=0 -#define ACQUIRE_LOCK(l) win32_acquire_lock(l) -#define RELEASE_LOCK(l) win32_release_lock(l) -#if HAVE_MORECORE -static MLOCK_T morecore_mutex; -#endif /* HAVE_MORECORE */ -static MLOCK_T magic_init_mutex; -#endif /* WIN32 */ - -#define USE_LOCK_BIT (2U) -#else /* USE_LOCKS */ -#define USE_LOCK_BIT (0U) -#define INITIAL_LOCK(l) -#endif /* USE_LOCKS */ - -#if USE_LOCKS && HAVE_MORECORE -#define ACQUIRE_MORECORE_LOCK() ACQUIRE_LOCK(&morecore_mutex); -#define RELEASE_MORECORE_LOCK() RELEASE_LOCK(&morecore_mutex); -#else /* USE_LOCKS && HAVE_MORECORE */ -#define ACQUIRE_MORECORE_LOCK() -#define RELEASE_MORECORE_LOCK() -#endif /* USE_LOCKS && HAVE_MORECORE */ - -#if USE_LOCKS -#define ACQUIRE_MAGIC_INIT_LOCK() ACQUIRE_LOCK(&magic_init_mutex); -#define RELEASE_MAGIC_INIT_LOCK() RELEASE_LOCK(&magic_init_mutex); -#else /* USE_LOCKS */ -#define ACQUIRE_MAGIC_INIT_LOCK() -#define RELEASE_MAGIC_INIT_LOCK() -#endif /* USE_LOCKS */ - - -/* ----------------------- Chunk representations ------------------------ */ - -/* - (The following includes lightly edited explanations by Colin Plumb.) - - The malloc_chunk declaration below is misleading (but accurate and - necessary). It declares a "view" into memory allowing access to - necessary fields at known offsets from a given base. - - Chunks of memory are maintained using a `boundary tag' method as - originally described by Knuth. (See the paper by Paul Wilson - ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a survey of such - techniques.) Sizes of free chunks are stored both in the front of - each chunk and at the end. This makes consolidating fragmented - chunks into bigger chunks fast. The head fields also hold bits - representing whether chunks are free or in use. - - Here are some pictures to make it clearer. They are "exploded" to - show that the state of a chunk can be thought of as extending from - the high 31 bits of the head field of its header through the - prev_foot and PINUSE_BIT bit of the following chunk header. - - A chunk that's in use looks like: - - chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Size of previous chunk (if P = 1) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| - | Size of this chunk 1| +-+ - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | | - +- -+ - | | - +- -+ - | : - +- size - sizeof(size_t) available payload bytes -+ - : | - chunk-> +- -+ - | | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1| - | Size of next chunk (may or may not be in use) | +-+ - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - - And if it's free, it looks like this: - - chunk-> +- -+ - | User payload (must be in use, or we would have merged!) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| - | Size of this chunk 0| +-+ - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Next pointer | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Prev pointer | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | : - +- size - sizeof(struct chunk) unused bytes -+ - : | - chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Size of this chunk | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| - | Size of next chunk (must be in use, or we would have merged)| +-+ - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | : - +- User payload -+ - : | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - |0| - +-+ - Note that since we always merge adjacent free chunks, the chunks - adjacent to a free chunk must be in use. - - Given a pointer to a chunk (which can be derived trivially from the - payload pointer) we can, in O(1) time, find out whether the adjacent - chunks are free, and if so, unlink them from the lists that they - are on and merge them with the current chunk. - - Chunks always begin on even word boundaries, so the mem portion - (which is returned to the user) is also on an even word boundary, and - thus at least double-word aligned. - - The P (PINUSE_BIT) bit, stored in the unused low-order bit of the - chunk size (which is always a multiple of two words), is an in-use - bit for the *previous* chunk. If that bit is *clear*, then the - word before the current chunk size contains the previous chunk - size, and can be used to find the front of the previous chunk. - The very first chunk allocated always has this bit set, preventing - access to non-existent (or non-owned) memory. If pinuse is set for - any given chunk, then you CANNOT determine the size of the - previous chunk, and might even get a memory addressing fault when - trying to do so. - - The C (CINUSE_BIT) bit, stored in the unused second-lowest bit of - the chunk size redundantly records whether the current chunk is - inuse. This redundancy enables usage checks within free and realloc, - and reduces indirection when freeing and consolidating chunks. - - Each freshly allocated chunk must have both cinuse and pinuse set. - That is, each allocated chunk borders either a previously allocated - and still in-use chunk, or the base of its memory arena. This is - ensured by making all allocations from the the `lowest' part of any - found chunk. Further, no free chunk physically borders another one, - so each free chunk is known to be preceded and followed by either - inuse chunks or the ends of memory. - - Note that the `foot' of the current chunk is actually represented - as the prev_foot of the NEXT chunk. This makes it easier to - deal with alignments etc but can be very confusing when trying - to extend or adapt this code. - - The exceptions to all this are - - 1. The special chunk `top' is the top-most available chunk (i.e., - the one bordering the end of available memory). It is treated - specially. Top is never included in any bin, is used only if - no other chunk is available, and is released back to the - system if it is very large (see M_TRIM_THRESHOLD). In effect, - the top chunk is treated as larger (and thus less well - fitting) than any other available chunk. The top chunk - doesn't update its trailing size field since there is no next - contiguous chunk that would have to index off it. However, - space is still allocated for it (TOP_FOOT_SIZE) to enable - separation or merging when space is extended. - - 3. Chunks allocated via mmap, which have the lowest-order bit - (IS_MMAPPED_BIT) set in their prev_foot fields, and do not set - PINUSE_BIT in their head fields. Because they are allocated - one-by-one, each must carry its own prev_foot field, which is - also used to hold the offset this chunk has within its mmapped - region, which is needed to preserve alignment. Each mmapped - chunk is trailed by the first two fields of a fake next-chunk - for sake of usage checks. - -*/ - -struct malloc_chunk { - size_t prev_foot; /* Size of previous chunk (if free). */ - size_t head; /* Size and inuse bits. */ - struct malloc_chunk* fd; /* double links -- used only if free. */ - struct malloc_chunk* bk; -}; - -typedef struct malloc_chunk mchunk; -typedef struct malloc_chunk* mchunkptr; -typedef struct malloc_chunk* sbinptr; /* The type of bins of chunks */ -typedef unsigned int bindex_t; /* Described below */ -typedef unsigned int binmap_t; /* Described below */ -typedef unsigned int flag_t; /* The type of various bit flag sets */ - -/* ------------------- Chunks sizes and alignments ----------------------- */ - -#define MCHUNK_SIZE (sizeof(mchunk)) - -#if FOOTERS -#define CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) -#else /* FOOTERS */ -#define CHUNK_OVERHEAD (SIZE_T_SIZE) -#endif /* FOOTERS */ - -/* MMapped chunks need a second word of overhead ... */ -#define MMAP_CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) -/* ... and additional padding for fake next-chunk at foot */ -#define MMAP_FOOT_PAD (FOUR_SIZE_T_SIZES) - -/* The smallest size we can malloc is an aligned minimal chunk */ -#define MIN_CHUNK_SIZE\ - ((MCHUNK_SIZE + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) - -/* conversion from malloc headers to user pointers, and back */ -#define chunk2mem(p) ((void*)((char*)(p) + TWO_SIZE_T_SIZES)) -#define mem2chunk(mem) ((mchunkptr)((char*)(mem) - TWO_SIZE_T_SIZES)) -/* chunk associated with aligned address A */ -#define align_as_chunk(A) (mchunkptr)((A) + align_offset(chunk2mem(A))) - -/* Bounds on request (not chunk) sizes. */ -#define MAX_REQUEST ((-MIN_CHUNK_SIZE) << 2) -#define MIN_REQUEST (MIN_CHUNK_SIZE - CHUNK_OVERHEAD - SIZE_T_ONE) - -/* pad request bytes into a usable size */ -#define pad_request(req) \ - (((req) + CHUNK_OVERHEAD + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) - -/* pad request, checking for minimum (but not maximum) */ -#define request2size(req) \ - (((req) < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(req)) - - -/* ------------------ Operations on head and foot fields ----------------- */ - -/* - The head field of a chunk is or'ed with PINUSE_BIT when previous - adjacent chunk in use, and or'ed with CINUSE_BIT if this chunk is in - use. If the chunk was obtained with mmap, the prev_foot field has - IS_MMAPPED_BIT set, otherwise holding the offset of the base of the - mmapped region to the base of the chunk. -*/ - -#define PINUSE_BIT (SIZE_T_ONE) -#define CINUSE_BIT (SIZE_T_TWO) -#define INUSE_BITS (PINUSE_BIT|CINUSE_BIT) - -/* Head value for fenceposts */ -#define FENCEPOST_HEAD (INUSE_BITS|SIZE_T_SIZE) - -/* extraction of fields from head words */ -#define cinuse(p) ((p)->head & CINUSE_BIT) -#define pinuse(p) ((p)->head & PINUSE_BIT) -#define chunksize(p) ((p)->head & ~(INUSE_BITS)) - -#define clear_pinuse(p) ((p)->head &= ~PINUSE_BIT) -#define clear_cinuse(p) ((p)->head &= ~CINUSE_BIT) - -/* Treat space at ptr +/- offset as a chunk */ -#define chunk_plus_offset(p, s) ((mchunkptr)(((char*)(p)) + (s))) -#define chunk_minus_offset(p, s) ((mchunkptr)(((char*)(p)) - (s))) - -/* Ptr to next or previous physical malloc_chunk. */ -#define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->head & ~INUSE_BITS))) -#define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_foot) )) - -/* extract next chunk's pinuse bit */ -#define next_pinuse(p) ((next_chunk(p)->head) & PINUSE_BIT) - -/* Get/set size at footer */ -#define get_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot) -#define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot = (s)) - -/* Set size, pinuse bit, and foot */ -#define set_size_and_pinuse_of_free_chunk(p, s)\ - ((p)->head = (s|PINUSE_BIT), set_foot(p, s)) - -/* Set size, pinuse bit, foot, and clear next pinuse */ -#define set_free_with_pinuse(p, s, n)\ - (clear_pinuse(n), set_size_and_pinuse_of_free_chunk(p, s)) - -#define is_mmapped(p)\ - (!((p)->head & PINUSE_BIT) && ((p)->prev_foot & IS_MMAPPED_BIT)) - -/* Get the internal overhead associated with chunk p */ -#define overhead_for(p)\ - (is_mmapped(p)? MMAP_CHUNK_OVERHEAD : CHUNK_OVERHEAD) - -/* Return true if malloced space is not necessarily cleared */ -#if MMAP_CLEARS -#define calloc_must_clear(p) (!is_mmapped(p)) -#else /* MMAP_CLEARS */ -#define calloc_must_clear(p) (1) -#endif /* MMAP_CLEARS */ - -/* ---------------------- Overlaid data structures ----------------------- */ - -/* - When chunks are not in use, they are treated as nodes of either - lists or trees. - - "Small" chunks are stored in circular doubly-linked lists, and look - like this: - - chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Size of previous chunk | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - `head:' | Size of chunk, in bytes |P| - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Forward pointer to next chunk in list | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Back pointer to previous chunk in list | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Unused space (may be 0 bytes long) . - . . - . | -nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - `foot:' | Size of chunk, in bytes | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - - Larger chunks are kept in a form of bitwise digital trees (aka - tries) keyed on chunksizes. Because malloc_tree_chunks are only for - free chunks greater than 256 bytes, their size doesn't impose any - constraints on user chunk sizes. Each node looks like: - - chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Size of previous chunk | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - `head:' | Size of chunk, in bytes |P| - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Forward pointer to next chunk of same size | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Back pointer to previous chunk of same size | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Pointer to left child (child[0]) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Pointer to right child (child[1]) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Pointer to parent | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | bin index of this chunk | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Unused space . - . | -nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - `foot:' | Size of chunk, in bytes | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - - Each tree holding treenodes is a tree of unique chunk sizes. Chunks - of the same size are arranged in a circularly-linked list, with only - the oldest chunk (the next to be used, in our FIFO ordering) - actually in the tree. (Tree members are distinguished by a non-null - parent pointer.) If a chunk with the same size an an existing node - is inserted, it is linked off the existing node using pointers that - work in the same way as fd/bk pointers of small chunks. - - Each tree contains a power of 2 sized range of chunk sizes (the - smallest is 0x100 <= x < 0x180), which is is divided in half at each - tree level, with the chunks in the smaller half of the range (0x100 - <= x < 0x140 for the top nose) in the left subtree and the larger - half (0x140 <= x < 0x180) in the right subtree. This is, of course, - done by inspecting individual bits. - - Using these rules, each node's left subtree contains all smaller - sizes than its right subtree. However, the node at the root of each - subtree has no particular ordering relationship to either. (The - dividing line between the subtree sizes is based on trie relation.) - If we remove the last chunk of a given size from the interior of the - tree, we need to replace it with a leaf node. The tree ordering - rules permit a node to be replaced by any leaf below it. - - The smallest chunk in a tree (a common operation in a best-fit - allocator) can be found by walking a path to the leftmost leaf in - the tree. Unlike a usual binary tree, where we follow left child - pointers until we reach a null, here we follow the right child - pointer any time the left one is null, until we reach a leaf with - both child pointers null. The smallest chunk in the tree will be - somewhere along that path. - - The worst case number of steps to add, find, or remove a node is - bounded by the number of bits differentiating chunks within - bins. Under current bin calculations, this ranges from 6 up to 21 - (for 32 bit sizes) or up to 53 (for 64 bit sizes). The typical case - is of course much better. -*/ - -struct malloc_tree_chunk { - /* The first four fields must be compatible with malloc_chunk */ - size_t prev_foot; - size_t head; - struct malloc_tree_chunk* fd; - struct malloc_tree_chunk* bk; - - struct malloc_tree_chunk* child[2]; - struct malloc_tree_chunk* parent; - bindex_t index; -}; - -typedef struct malloc_tree_chunk tchunk; -typedef struct malloc_tree_chunk* tchunkptr; -typedef struct malloc_tree_chunk* tbinptr; /* The type of bins of trees */ - -/* A little helper macro for trees */ -#define leftmost_child(t) ((t)->child[0] != 0? (t)->child[0] : (t)->child[1]) - -/* ----------------------------- Segments -------------------------------- */ - -/* - Each malloc space may include non-contiguous segments, held in a - list headed by an embedded malloc_segment record representing the - top-most space. Segments also include flags holding properties of - the space. Large chunks that are directly allocated by mmap are not - included in this list. They are instead independently created and - destroyed without otherwise keeping track of them. - - Segment management mainly comes into play for spaces allocated by - MMAP. Any call to MMAP might or might not return memory that is - adjacent to an existing segment. MORECORE normally contiguously - extends the current space, so this space is almost always adjacent, - which is simpler and faster to deal with. (This is why MORECORE is - used preferentially to MMAP when both are available -- see - sys_alloc.) When allocating using MMAP, we don't use any of the - hinting mechanisms (inconsistently) supported in various - implementations of unix mmap, or distinguish reserving from - committing memory. Instead, we just ask for space, and exploit - contiguity when we get it. It is probably possible to do - better than this on some systems, but no general scheme seems - to be significantly better. - - Management entails a simpler variant of the consolidation scheme - used for chunks to reduce fragmentation -- new adjacent memory is - normally prepended or appended to an existing segment. However, - there are limitations compared to chunk consolidation that mostly - reflect the fact that segment processing is relatively infrequent - (occurring only when getting memory from system) and that we - don't expect to have huge numbers of segments: - - * Segments are not indexed, so traversal requires linear scans. (It - would be possible to index these, but is not worth the extra - overhead and complexity for most programs on most platforms.) - * New segments are only appended to old ones when holding top-most - memory; if they cannot be prepended to others, they are held in - different segments. - - Except for the top-most segment of an mstate, each segment record - is kept at the tail of its segment. Segments are added by pushing - segment records onto the list headed by &mstate.seg for the - containing mstate. - - Segment flags control allocation/merge/deallocation policies: - * If EXTERN_BIT set, then we did not allocate this segment, - and so should not try to deallocate or merge with others. - (This currently holds only for the initial segment passed - into create_mspace_with_base.) - * If IS_MMAPPED_BIT set, the segment may be merged with - other surrounding mmapped segments and trimmed/de-allocated - using munmap. - * If neither bit is set, then the segment was obtained using - MORECORE so can be merged with surrounding MORECORE'd segments - and deallocated/trimmed using MORECORE with negative arguments. -*/ - -struct malloc_segment { - char* base; /* base address */ - size_t size; /* allocated size */ - struct malloc_segment* next; /* ptr to next segment */ -#if FFI_MMAP_EXEC_WRIT - /* The mmap magic is supposed to store the address of the executable - segment at the very end of the requested block. */ - -# define mmap_exec_offset(b,s) (*(ptrdiff_t*)((b)+(s)-sizeof(ptrdiff_t))) - - /* We can only merge segments if their corresponding executable - segments are at identical offsets. */ -# define check_segment_merge(S,b,s) \ - (mmap_exec_offset((b),(s)) == (S)->exec_offset) - -# define add_segment_exec_offset(p,S) ((char*)(p) + (S)->exec_offset) -# define sub_segment_exec_offset(p,S) ((char*)(p) - (S)->exec_offset) - - /* The removal of sflags only works with HAVE_MORECORE == 0. */ - -# define get_segment_flags(S) (IS_MMAPPED_BIT) -# define set_segment_flags(S,v) \ - (((v) != IS_MMAPPED_BIT) ? (ABORT, (v)) : \ - (((S)->exec_offset = \ - mmap_exec_offset((S)->base, (S)->size)), \ - (mmap_exec_offset((S)->base + (S)->exec_offset, (S)->size) != \ - (S)->exec_offset) ? (ABORT, (v)) : \ - (mmap_exec_offset((S)->base, (S)->size) = 0), (v))) - - /* We use an offset here, instead of a pointer, because then, when - base changes, we don't have to modify this. On architectures - with segmented addresses, this might not work. */ - ptrdiff_t exec_offset; -#else - -# define get_segment_flags(S) ((S)->sflags) -# define set_segment_flags(S,v) ((S)->sflags = (v)) -# define check_segment_merge(S,b,s) (1) - - flag_t sflags; /* mmap and extern flag */ -#endif -}; - -#define is_mmapped_segment(S) (get_segment_flags(S) & IS_MMAPPED_BIT) -#define is_extern_segment(S) (get_segment_flags(S) & EXTERN_BIT) - -typedef struct malloc_segment msegment; -typedef struct malloc_segment* msegmentptr; - -/* ---------------------------- malloc_state ----------------------------- */ - -/* - A malloc_state holds all of the bookkeeping for a space. - The main fields are: - - Top - The topmost chunk of the currently active segment. Its size is - cached in topsize. The actual size of topmost space is - topsize+TOP_FOOT_SIZE, which includes space reserved for adding - fenceposts and segment records if necessary when getting more - space from the system. The size at which to autotrim top is - cached from mparams in trim_check, except that it is disabled if - an autotrim fails. - - Designated victim (dv) - This is the preferred chunk for servicing small requests that - don't have exact fits. It is normally the chunk split off most - recently to service another small request. Its size is cached in - dvsize. The link fields of this chunk are not maintained since it - is not kept in a bin. - - SmallBins - An array of bin headers for free chunks. These bins hold chunks - with sizes less than MIN_LARGE_SIZE bytes. Each bin contains - chunks of all the same size, spaced 8 bytes apart. To simplify - use in double-linked lists, each bin header acts as a malloc_chunk - pointing to the real first node, if it exists (else pointing to - itself). This avoids special-casing for headers. But to avoid - waste, we allocate only the fd/bk pointers of bins, and then use - repositioning tricks to treat these as the fields of a chunk. - - TreeBins - Treebins are pointers to the roots of trees holding a range of - sizes. There are 2 equally spaced treebins for each power of two - from TREE_SHIFT to TREE_SHIFT+16. The last bin holds anything - larger. - - Bin maps - There is one bit map for small bins ("smallmap") and one for - treebins ("treemap). Each bin sets its bit when non-empty, and - clears the bit when empty. Bit operations are then used to avoid - bin-by-bin searching -- nearly all "search" is done without ever - looking at bins that won't be selected. The bit maps - conservatively use 32 bits per map word, even if on 64bit system. - For a good description of some of the bit-based techniques used - here, see Henry S. Warren Jr's book "Hacker's Delight" (and - supplement at http://hackersdelight.org/). Many of these are - intended to reduce the branchiness of paths through malloc etc, as - well as to reduce the number of memory locations read or written. - - Segments - A list of segments headed by an embedded malloc_segment record - representing the initial space. - - Address check support - The least_addr field is the least address ever obtained from - MORECORE or MMAP. Attempted frees and reallocs of any address less - than this are trapped (unless INSECURE is defined). - - Magic tag - A cross-check field that should always hold same value as mparams.magic. - - Flags - Bits recording whether to use MMAP, locks, or contiguous MORECORE - - Statistics - Each space keeps track of current and maximum system memory - obtained via MORECORE or MMAP. - - Locking - If USE_LOCKS is defined, the "mutex" lock is acquired and released - around every public call using this mspace. -*/ - -/* Bin types, widths and sizes */ -#define NSMALLBINS (32U) -#define NTREEBINS (32U) -#define SMALLBIN_SHIFT (3U) -#define SMALLBIN_WIDTH (SIZE_T_ONE << SMALLBIN_SHIFT) -#define TREEBIN_SHIFT (8U) -#define MIN_LARGE_SIZE (SIZE_T_ONE << TREEBIN_SHIFT) -#define MAX_SMALL_SIZE (MIN_LARGE_SIZE - SIZE_T_ONE) -#define MAX_SMALL_REQUEST (MAX_SMALL_SIZE - CHUNK_ALIGN_MASK - CHUNK_OVERHEAD) - -struct malloc_state { - binmap_t smallmap; - binmap_t treemap; - size_t dvsize; - size_t topsize; - char* least_addr; - mchunkptr dv; - mchunkptr top; - size_t trim_check; - size_t magic; - mchunkptr smallbins[(NSMALLBINS+1)*2]; - tbinptr treebins[NTREEBINS]; - size_t footprint; - size_t max_footprint; - flag_t mflags; -#if USE_LOCKS - MLOCK_T mutex; /* locate lock among fields that rarely change */ -#endif /* USE_LOCKS */ - msegment seg; -}; - -typedef struct malloc_state* mstate; - -/* ------------- Global malloc_state and malloc_params ------------------- */ - -/* - malloc_params holds global properties, including those that can be - dynamically set using mallopt. There is a single instance, mparams, - initialized in init_mparams. -*/ - -struct malloc_params { - size_t magic; - size_t page_size; - size_t granularity; - size_t mmap_threshold; - size_t trim_threshold; - flag_t default_mflags; -}; - -static struct malloc_params mparams; - -/* The global malloc_state used for all non-"mspace" calls */ -static struct malloc_state _gm_; -#define gm (&_gm_) -#define is_global(M) ((M) == &_gm_) -#define is_initialized(M) ((M)->top != 0) - -/* -------------------------- system alloc setup ------------------------- */ - -/* Operations on mflags */ - -#define use_lock(M) ((M)->mflags & USE_LOCK_BIT) -#define enable_lock(M) ((M)->mflags |= USE_LOCK_BIT) -#define disable_lock(M) ((M)->mflags &= ~USE_LOCK_BIT) - -#define use_mmap(M) ((M)->mflags & USE_MMAP_BIT) -#define enable_mmap(M) ((M)->mflags |= USE_MMAP_BIT) -#define disable_mmap(M) ((M)->mflags &= ~USE_MMAP_BIT) - -#define use_noncontiguous(M) ((M)->mflags & USE_NONCONTIGUOUS_BIT) -#define disable_contiguous(M) ((M)->mflags |= USE_NONCONTIGUOUS_BIT) - -#define set_lock(M,L)\ - ((M)->mflags = (L)?\ - ((M)->mflags | USE_LOCK_BIT) :\ - ((M)->mflags & ~USE_LOCK_BIT)) - -/* page-align a size */ -#define page_align(S)\ - (((S) + (mparams.page_size)) & ~(mparams.page_size - SIZE_T_ONE)) - -/* granularity-align a size */ -#define granularity_align(S)\ - (((S) + (mparams.granularity)) & ~(mparams.granularity - SIZE_T_ONE)) - -#define is_page_aligned(S)\ - (((size_t)(S) & (mparams.page_size - SIZE_T_ONE)) == 0) -#define is_granularity_aligned(S)\ - (((size_t)(S) & (mparams.granularity - SIZE_T_ONE)) == 0) - -/* True if segment S holds address A */ -#define segment_holds(S, A)\ - ((char*)(A) >= S->base && (char*)(A) < S->base + S->size) - -/* Return segment holding given address */ -static msegmentptr segment_holding(mstate m, char* addr) { - msegmentptr sp = &m->seg; - for (;;) { - if (addr >= sp->base && addr < sp->base + sp->size) - return sp; - if ((sp = sp->next) == 0) - return 0; - } -} - -/* Return true if segment contains a segment link */ -static int has_segment_link(mstate m, msegmentptr ss) { - msegmentptr sp = &m->seg; - for (;;) { - if ((char*)sp >= ss->base && (char*)sp < ss->base + ss->size) - return 1; - if ((sp = sp->next) == 0) - return 0; - } -} - -#ifndef MORECORE_CANNOT_TRIM -#define should_trim(M,s) ((s) > (M)->trim_check) -#else /* MORECORE_CANNOT_TRIM */ -#define should_trim(M,s) (0) -#endif /* MORECORE_CANNOT_TRIM */ - -/* - TOP_FOOT_SIZE is padding at the end of a segment, including space - that may be needed to place segment records and fenceposts when new - noncontiguous segments are added. -*/ -#define TOP_FOOT_SIZE\ - (align_offset(chunk2mem(0))+pad_request(sizeof(struct malloc_segment))+MIN_CHUNK_SIZE) - - -/* ------------------------------- Hooks -------------------------------- */ - -/* - PREACTION should be defined to return 0 on success, and nonzero on - failure. If you are not using locking, you can redefine these to do - anything you like. -*/ - -#if USE_LOCKS - -/* Ensure locks are initialized */ -#define GLOBALLY_INITIALIZE() (mparams.page_size == 0 && init_mparams()) - -#define PREACTION(M) ((GLOBALLY_INITIALIZE() || use_lock(M))? ACQUIRE_LOCK(&(M)->mutex) : 0) -#define POSTACTION(M) { if (use_lock(M)) RELEASE_LOCK(&(M)->mutex); } -#else /* USE_LOCKS */ - -#ifndef PREACTION -#define PREACTION(M) (0) -#endif /* PREACTION */ - -#ifndef POSTACTION -#define POSTACTION(M) -#endif /* POSTACTION */ - -#endif /* USE_LOCKS */ - -/* - CORRUPTION_ERROR_ACTION is triggered upon detected bad addresses. - USAGE_ERROR_ACTION is triggered on detected bad frees and - reallocs. The argument p is an address that might have triggered the - fault. It is ignored by the two predefined actions, but might be - useful in custom actions that try to help diagnose errors. -*/ - -#if PROCEED_ON_ERROR - -/* A count of the number of corruption errors causing resets */ -int malloc_corruption_error_count; - -/* default corruption action */ -static void reset_on_error(mstate m); - -#define CORRUPTION_ERROR_ACTION(m) reset_on_error(m) -#define USAGE_ERROR_ACTION(m, p) - -#else /* PROCEED_ON_ERROR */ - -#ifndef CORRUPTION_ERROR_ACTION -#define CORRUPTION_ERROR_ACTION(m) ABORT -#endif /* CORRUPTION_ERROR_ACTION */ - -#ifndef USAGE_ERROR_ACTION -#define USAGE_ERROR_ACTION(m,p) ABORT -#endif /* USAGE_ERROR_ACTION */ - -#endif /* PROCEED_ON_ERROR */ - -/* -------------------------- Debugging setup ---------------------------- */ - -#if ! DEBUG - -#define check_free_chunk(M,P) -#define check_inuse_chunk(M,P) -#define check_malloced_chunk(M,P,N) -#define check_mmapped_chunk(M,P) -#define check_malloc_state(M) -#define check_top_chunk(M,P) - -#else /* DEBUG */ -#define check_free_chunk(M,P) do_check_free_chunk(M,P) -#define check_inuse_chunk(M,P) do_check_inuse_chunk(M,P) -#define check_top_chunk(M,P) do_check_top_chunk(M,P) -#define check_malloced_chunk(M,P,N) do_check_malloced_chunk(M,P,N) -#define check_mmapped_chunk(M,P) do_check_mmapped_chunk(M,P) -#define check_malloc_state(M) do_check_malloc_state(M) - -static void do_check_any_chunk(mstate m, mchunkptr p); -static void do_check_top_chunk(mstate m, mchunkptr p); -static void do_check_mmapped_chunk(mstate m, mchunkptr p); -static void do_check_inuse_chunk(mstate m, mchunkptr p); -static void do_check_free_chunk(mstate m, mchunkptr p); -static void do_check_malloced_chunk(mstate m, void* mem, size_t s); -static void do_check_tree(mstate m, tchunkptr t); -static void do_check_treebin(mstate m, bindex_t i); -static void do_check_smallbin(mstate m, bindex_t i); -static void do_check_malloc_state(mstate m); -static int bin_find(mstate m, mchunkptr x); -static size_t traverse_and_check(mstate m); -#endif /* DEBUG */ - -/* ---------------------------- Indexing Bins ---------------------------- */ - -#define is_small(s) (((s) >> SMALLBIN_SHIFT) < NSMALLBINS) -#define small_index(s) ((s) >> SMALLBIN_SHIFT) -#define small_index2size(i) ((i) << SMALLBIN_SHIFT) -#define MIN_SMALL_INDEX (small_index(MIN_CHUNK_SIZE)) - -/* addressing by index. See above about smallbin repositioning */ -#define smallbin_at(M, i) ((sbinptr)((char*)&((M)->smallbins[(i)<<1]))) -#define treebin_at(M,i) (&((M)->treebins[i])) - -/* assign tree index for size S to variable I */ -#if defined(__GNUC__) && defined(i386) -#define compute_tree_index(S, I)\ -{\ - size_t X = S >> TREEBIN_SHIFT;\ - if (X == 0)\ - I = 0;\ - else if (X > 0xFFFF)\ - I = NTREEBINS-1;\ - else {\ - unsigned int K;\ - __asm__("bsrl %1,%0\n\t" : "=r" (K) : "rm" (X));\ - I = (bindex_t)((K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1)));\ - }\ -} -#else /* GNUC */ -#define compute_tree_index(S, I)\ -{\ - size_t X = S >> TREEBIN_SHIFT;\ - if (X == 0)\ - I = 0;\ - else if (X > 0xFFFF)\ - I = NTREEBINS-1;\ - else {\ - unsigned int Y = (unsigned int)X;\ - unsigned int N = ((Y - 0x100) >> 16) & 8;\ - unsigned int K = (((Y <<= N) - 0x1000) >> 16) & 4;\ - N += K;\ - N += K = (((Y <<= K) - 0x4000) >> 16) & 2;\ - K = 14 - N + ((Y <<= K) >> 15);\ - I = (K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1));\ - }\ -} -#endif /* GNUC */ - -/* Bit representing maximum resolved size in a treebin at i */ -#define bit_for_tree_index(i) \ - (i == NTREEBINS-1)? (SIZE_T_BITSIZE-1) : (((i) >> 1) + TREEBIN_SHIFT - 2) - -/* Shift placing maximum resolved bit in a treebin at i as sign bit */ -#define leftshift_for_tree_index(i) \ - ((i == NTREEBINS-1)? 0 : \ - ((SIZE_T_BITSIZE-SIZE_T_ONE) - (((i) >> 1) + TREEBIN_SHIFT - 2))) - -/* The size of the smallest chunk held in bin with index i */ -#define minsize_for_tree_index(i) \ - ((SIZE_T_ONE << (((i) >> 1) + TREEBIN_SHIFT)) | \ - (((size_t)((i) & SIZE_T_ONE)) << (((i) >> 1) + TREEBIN_SHIFT - 1))) - - -/* ------------------------ Operations on bin maps ----------------------- */ - -/* bit corresponding to given index */ -#define idx2bit(i) ((binmap_t)(1) << (i)) - -/* Mark/Clear bits with given index */ -#define mark_smallmap(M,i) ((M)->smallmap |= idx2bit(i)) -#define clear_smallmap(M,i) ((M)->smallmap &= ~idx2bit(i)) -#define smallmap_is_marked(M,i) ((M)->smallmap & idx2bit(i)) - -#define mark_treemap(M,i) ((M)->treemap |= idx2bit(i)) -#define clear_treemap(M,i) ((M)->treemap &= ~idx2bit(i)) -#define treemap_is_marked(M,i) ((M)->treemap & idx2bit(i)) - -/* index corresponding to given bit */ - -#if defined(__GNUC__) && defined(i386) -#define compute_bit2idx(X, I)\ -{\ - unsigned int J;\ - __asm__("bsfl %1,%0\n\t" : "=r" (J) : "rm" (X));\ - I = (bindex_t)J;\ -} - -#else /* GNUC */ -#if USE_BUILTIN_FFS -#define compute_bit2idx(X, I) I = ffs(X)-1 - -#else /* USE_BUILTIN_FFS */ -#define compute_bit2idx(X, I)\ -{\ - unsigned int Y = X - 1;\ - unsigned int K = Y >> (16-4) & 16;\ - unsigned int N = K; Y >>= K;\ - N += K = Y >> (8-3) & 8; Y >>= K;\ - N += K = Y >> (4-2) & 4; Y >>= K;\ - N += K = Y >> (2-1) & 2; Y >>= K;\ - N += K = Y >> (1-0) & 1; Y >>= K;\ - I = (bindex_t)(N + Y);\ -} -#endif /* USE_BUILTIN_FFS */ -#endif /* GNUC */ - -/* isolate the least set bit of a bitmap */ -#define least_bit(x) ((x) & -(x)) - -/* mask with all bits to left of least bit of x on */ -#define left_bits(x) ((x<<1) | -(x<<1)) - -/* mask with all bits to left of or equal to least bit of x on */ -#define same_or_left_bits(x) ((x) | -(x)) - - -/* ----------------------- Runtime Check Support ------------------------- */ - -/* - For security, the main invariant is that malloc/free/etc never - writes to a static address other than malloc_state, unless static - malloc_state itself has been corrupted, which cannot occur via - malloc (because of these checks). In essence this means that we - believe all pointers, sizes, maps etc held in malloc_state, but - check all of those linked or offsetted from other embedded data - structures. These checks are interspersed with main code in a way - that tends to minimize their run-time cost. - - When FOOTERS is defined, in addition to range checking, we also - verify footer fields of inuse chunks, which can be used guarantee - that the mstate controlling malloc/free is intact. This is a - streamlined version of the approach described by William Robertson - et al in "Run-time Detection of Heap-based Overflows" LISA'03 - http://www.usenix.org/events/lisa03/tech/robertson.html The footer - of an inuse chunk holds the xor of its mstate and a random seed, - that is checked upon calls to free() and realloc(). This is - (probablistically) unguessable from outside the program, but can be - computed by any code successfully malloc'ing any chunk, so does not - itself provide protection against code that has already broken - security through some other means. Unlike Robertson et al, we - always dynamically check addresses of all offset chunks (previous, - next, etc). This turns out to be cheaper than relying on hashes. -*/ - -#if !INSECURE -/* Check if address a is at least as high as any from MORECORE or MMAP */ -#define ok_address(M, a) ((char*)(a) >= (M)->least_addr) -/* Check if address of next chunk n is higher than base chunk p */ -#define ok_next(p, n) ((char*)(p) < (char*)(n)) -/* Check if p has its cinuse bit on */ -#define ok_cinuse(p) cinuse(p) -/* Check if p has its pinuse bit on */ -#define ok_pinuse(p) pinuse(p) - -#else /* !INSECURE */ -#define ok_address(M, a) (1) -#define ok_next(b, n) (1) -#define ok_cinuse(p) (1) -#define ok_pinuse(p) (1) -#endif /* !INSECURE */ - -#if (FOOTERS && !INSECURE) -/* Check if (alleged) mstate m has expected magic field */ -#define ok_magic(M) ((M)->magic == mparams.magic) -#else /* (FOOTERS && !INSECURE) */ -#define ok_magic(M) (1) -#endif /* (FOOTERS && !INSECURE) */ - - -/* In gcc, use __builtin_expect to minimize impact of checks */ -#if !INSECURE -#if defined(__GNUC__) && __GNUC__ >= 3 -#define RTCHECK(e) __builtin_expect(e, 1) -#else /* GNUC */ -#define RTCHECK(e) (e) -#endif /* GNUC */ -#else /* !INSECURE */ -#define RTCHECK(e) (1) -#endif /* !INSECURE */ - -/* macros to set up inuse chunks with or without footers */ - -#if !FOOTERS - -#define mark_inuse_foot(M,p,s) - -/* Set cinuse bit and pinuse bit of next chunk */ -#define set_inuse(M,p,s)\ - ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ - ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) - -/* Set cinuse and pinuse of this chunk and pinuse of next chunk */ -#define set_inuse_and_pinuse(M,p,s)\ - ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ - ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) - -/* Set size, cinuse and pinuse bit of this chunk */ -#define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ - ((p)->head = (s|PINUSE_BIT|CINUSE_BIT)) - -#else /* FOOTERS */ - -/* Set foot of inuse chunk to be xor of mstate and seed */ -#define mark_inuse_foot(M,p,s)\ - (((mchunkptr)((char*)(p) + (s)))->prev_foot = ((size_t)(M) ^ mparams.magic)) - -#define get_mstate_for(p)\ - ((mstate)(((mchunkptr)((char*)(p) +\ - (chunksize(p))))->prev_foot ^ mparams.magic)) - -#define set_inuse(M,p,s)\ - ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ - (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT), \ - mark_inuse_foot(M,p,s)) - -#define set_inuse_and_pinuse(M,p,s)\ - ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ - (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT),\ - mark_inuse_foot(M,p,s)) - -#define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ - ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ - mark_inuse_foot(M, p, s)) - -#endif /* !FOOTERS */ - -/* ---------------------------- setting mparams -------------------------- */ - -/* Initialize mparams */ -static int init_mparams(void) { - if (mparams.page_size == 0) { - size_t s; - - mparams.mmap_threshold = DEFAULT_MMAP_THRESHOLD; - mparams.trim_threshold = DEFAULT_TRIM_THRESHOLD; -#if MORECORE_CONTIGUOUS - mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT; -#else /* MORECORE_CONTIGUOUS */ - mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT|USE_NONCONTIGUOUS_BIT; -#endif /* MORECORE_CONTIGUOUS */ - -#if (FOOTERS && !INSECURE) - { -#if USE_DEV_RANDOM - int fd; - unsigned char buf[sizeof(size_t)]; - /* Try to use /dev/urandom, else fall back on using time */ - if ((fd = open("/dev/urandom", O_RDONLY)) >= 0 && - read(fd, buf, sizeof(buf)) == sizeof(buf)) { - s = *((size_t *) buf); - close(fd); - } - else -#endif /* USE_DEV_RANDOM */ - s = (size_t)(time(0) ^ (size_t)0x55555555U); - - s |= (size_t)8U; /* ensure nonzero */ - s &= ~(size_t)7U; /* improve chances of fault for bad values */ - - } -#else /* (FOOTERS && !INSECURE) */ - s = (size_t)0x58585858U; -#endif /* (FOOTERS && !INSECURE) */ - ACQUIRE_MAGIC_INIT_LOCK(); - if (mparams.magic == 0) { - mparams.magic = s; - /* Set up lock for main malloc area */ - INITIAL_LOCK(&gm->mutex); - gm->mflags = mparams.default_mflags; - } - RELEASE_MAGIC_INIT_LOCK(); - -#if !defined(WIN32) && !defined(__OS2__) - mparams.page_size = malloc_getpagesize; - mparams.granularity = ((DEFAULT_GRANULARITY != 0)? - DEFAULT_GRANULARITY : mparams.page_size); -#elif defined (__OS2__) - /* if low-memory is used, os2munmap() would break - if it were anything other than 64k */ - mparams.page_size = 4096u; - mparams.granularity = 65536u; -#else /* WIN32 */ - { - SYSTEM_INFO system_info; - GetSystemInfo(&system_info); - mparams.page_size = system_info.dwPageSize; - mparams.granularity = system_info.dwAllocationGranularity; - } -#endif /* WIN32 */ - - /* Sanity-check configuration: - size_t must be unsigned and as wide as pointer type. - ints must be at least 4 bytes. - alignment must be at least 8. - Alignment, min chunk size, and page size must all be powers of 2. - */ - if ((sizeof(size_t) != sizeof(char*)) || - (MAX_SIZE_T < MIN_CHUNK_SIZE) || - (sizeof(int) < 4) || - (MALLOC_ALIGNMENT < (size_t)8U) || - ((MALLOC_ALIGNMENT & (MALLOC_ALIGNMENT-SIZE_T_ONE)) != 0) || - ((MCHUNK_SIZE & (MCHUNK_SIZE-SIZE_T_ONE)) != 0) || - ((mparams.granularity & (mparams.granularity-SIZE_T_ONE)) != 0) || - ((mparams.page_size & (mparams.page_size-SIZE_T_ONE)) != 0)) - ABORT; - } - return 0; -} - -/* support for mallopt */ -static int change_mparam(int param_number, int value) { - size_t val = (size_t)value; - init_mparams(); - switch(param_number) { - case M_TRIM_THRESHOLD: - mparams.trim_threshold = val; - return 1; - case M_GRANULARITY: - if (val >= mparams.page_size && ((val & (val-1)) == 0)) { - mparams.granularity = val; - return 1; - } - else - return 0; - case M_MMAP_THRESHOLD: - mparams.mmap_threshold = val; - return 1; - default: - return 0; - } -} - -#if DEBUG -/* ------------------------- Debugging Support --------------------------- */ - -/* Check properties of any chunk, whether free, inuse, mmapped etc */ -static void do_check_any_chunk(mstate m, mchunkptr p) { - assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); - assert(ok_address(m, p)); -} - -/* Check properties of top chunk */ -static void do_check_top_chunk(mstate m, mchunkptr p) { - msegmentptr sp = segment_holding(m, (char*)p); - size_t sz = chunksize(p); - assert(sp != 0); - assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); - assert(ok_address(m, p)); - assert(sz == m->topsize); - assert(sz > 0); - assert(sz == ((sp->base + sp->size) - (char*)p) - TOP_FOOT_SIZE); - assert(pinuse(p)); - assert(!next_pinuse(p)); -} - -/* Check properties of (inuse) mmapped chunks */ -static void do_check_mmapped_chunk(mstate m, mchunkptr p) { - size_t sz = chunksize(p); - size_t len = (sz + (p->prev_foot & ~IS_MMAPPED_BIT) + MMAP_FOOT_PAD); - assert(is_mmapped(p)); - assert(use_mmap(m)); - assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); - assert(ok_address(m, p)); - assert(!is_small(sz)); - assert((len & (mparams.page_size-SIZE_T_ONE)) == 0); - assert(chunk_plus_offset(p, sz)->head == FENCEPOST_HEAD); - assert(chunk_plus_offset(p, sz+SIZE_T_SIZE)->head == 0); -} - -/* Check properties of inuse chunks */ -static void do_check_inuse_chunk(mstate m, mchunkptr p) { - do_check_any_chunk(m, p); - assert(cinuse(p)); - assert(next_pinuse(p)); - /* If not pinuse and not mmapped, previous chunk has OK offset */ - assert(is_mmapped(p) || pinuse(p) || next_chunk(prev_chunk(p)) == p); - if (is_mmapped(p)) - do_check_mmapped_chunk(m, p); -} - -/* Check properties of free chunks */ -static void do_check_free_chunk(mstate m, mchunkptr p) { - size_t sz = p->head & ~(PINUSE_BIT|CINUSE_BIT); - mchunkptr next = chunk_plus_offset(p, sz); - do_check_any_chunk(m, p); - assert(!cinuse(p)); - assert(!next_pinuse(p)); - assert (!is_mmapped(p)); - if (p != m->dv && p != m->top) { - if (sz >= MIN_CHUNK_SIZE) { - assert((sz & CHUNK_ALIGN_MASK) == 0); - assert(is_aligned(chunk2mem(p))); - assert(next->prev_foot == sz); - assert(pinuse(p)); - assert (next == m->top || cinuse(next)); - assert(p->fd->bk == p); - assert(p->bk->fd == p); - } - else /* markers are always of size SIZE_T_SIZE */ - assert(sz == SIZE_T_SIZE); - } -} - -/* Check properties of malloced chunks at the point they are malloced */ -static void do_check_malloced_chunk(mstate m, void* mem, size_t s) { - if (mem != 0) { - mchunkptr p = mem2chunk(mem); - size_t sz = p->head & ~(PINUSE_BIT|CINUSE_BIT); - do_check_inuse_chunk(m, p); - assert((sz & CHUNK_ALIGN_MASK) == 0); - assert(sz >= MIN_CHUNK_SIZE); - assert(sz >= s); - /* unless mmapped, size is less than MIN_CHUNK_SIZE more than request */ - assert(is_mmapped(p) || sz < (s + MIN_CHUNK_SIZE)); - } -} - -/* Check a tree and its subtrees. */ -static void do_check_tree(mstate m, tchunkptr t) { - tchunkptr head = 0; - tchunkptr u = t; - bindex_t tindex = t->index; - size_t tsize = chunksize(t); - bindex_t idx; - compute_tree_index(tsize, idx); - assert(tindex == idx); - assert(tsize >= MIN_LARGE_SIZE); - assert(tsize >= minsize_for_tree_index(idx)); - assert((idx == NTREEBINS-1) || (tsize < minsize_for_tree_index((idx+1)))); - - do { /* traverse through chain of same-sized nodes */ - do_check_any_chunk(m, ((mchunkptr)u)); - assert(u->index == tindex); - assert(chunksize(u) == tsize); - assert(!cinuse(u)); - assert(!next_pinuse(u)); - assert(u->fd->bk == u); - assert(u->bk->fd == u); - if (u->parent == 0) { - assert(u->child[0] == 0); - assert(u->child[1] == 0); - } - else { - assert(head == 0); /* only one node on chain has parent */ - head = u; - assert(u->parent != u); - assert (u->parent->child[0] == u || - u->parent->child[1] == u || - *((tbinptr*)(u->parent)) == u); - if (u->child[0] != 0) { - assert(u->child[0]->parent == u); - assert(u->child[0] != u); - do_check_tree(m, u->child[0]); - } - if (u->child[1] != 0) { - assert(u->child[1]->parent == u); - assert(u->child[1] != u); - do_check_tree(m, u->child[1]); - } - if (u->child[0] != 0 && u->child[1] != 0) { - assert(chunksize(u->child[0]) < chunksize(u->child[1])); - } - } - u = u->fd; - } while (u != t); - assert(head != 0); -} - -/* Check all the chunks in a treebin. */ -static void do_check_treebin(mstate m, bindex_t i) { - tbinptr* tb = treebin_at(m, i); - tchunkptr t = *tb; - int empty = (m->treemap & (1U << i)) == 0; - if (t == 0) - assert(empty); - if (!empty) - do_check_tree(m, t); -} - -/* Check all the chunks in a smallbin. */ -static void do_check_smallbin(mstate m, bindex_t i) { - sbinptr b = smallbin_at(m, i); - mchunkptr p = b->bk; - unsigned int empty = (m->smallmap & (1U << i)) == 0; - if (p == b) - assert(empty); - if (!empty) { - for (; p != b; p = p->bk) { - size_t size = chunksize(p); - mchunkptr q; - /* each chunk claims to be free */ - do_check_free_chunk(m, p); - /* chunk belongs in bin */ - assert(small_index(size) == i); - assert(p->bk == b || chunksize(p->bk) == chunksize(p)); - /* chunk is followed by an inuse chunk */ - q = next_chunk(p); - if (q->head != FENCEPOST_HEAD) - do_check_inuse_chunk(m, q); - } - } -} - -/* Find x in a bin. Used in other check functions. */ -static int bin_find(mstate m, mchunkptr x) { - size_t size = chunksize(x); - if (is_small(size)) { - bindex_t sidx = small_index(size); - sbinptr b = smallbin_at(m, sidx); - if (smallmap_is_marked(m, sidx)) { - mchunkptr p = b; - do { - if (p == x) - return 1; - } while ((p = p->fd) != b); - } - } - else { - bindex_t tidx; - compute_tree_index(size, tidx); - if (treemap_is_marked(m, tidx)) { - tchunkptr t = *treebin_at(m, tidx); - size_t sizebits = size << leftshift_for_tree_index(tidx); - while (t != 0 && chunksize(t) != size) { - t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; - sizebits <<= 1; - } - if (t != 0) { - tchunkptr u = t; - do { - if (u == (tchunkptr)x) - return 1; - } while ((u = u->fd) != t); - } - } - } - return 0; -} - -/* Traverse each chunk and check it; return total */ -static size_t traverse_and_check(mstate m) { - size_t sum = 0; - if (is_initialized(m)) { - msegmentptr s = &m->seg; - sum += m->topsize + TOP_FOOT_SIZE; - while (s != 0) { - mchunkptr q = align_as_chunk(s->base); - mchunkptr lastq = 0; - assert(pinuse(q)); - while (segment_holds(s, q) && - q != m->top && q->head != FENCEPOST_HEAD) { - sum += chunksize(q); - if (cinuse(q)) { - assert(!bin_find(m, q)); - do_check_inuse_chunk(m, q); - } - else { - assert(q == m->dv || bin_find(m, q)); - assert(lastq == 0 || cinuse(lastq)); /* Not 2 consecutive free */ - do_check_free_chunk(m, q); - } - lastq = q; - q = next_chunk(q); - } - s = s->next; - } - } - return sum; -} - -/* Check all properties of malloc_state. */ -static void do_check_malloc_state(mstate m) { - bindex_t i; - size_t total; - /* check bins */ - for (i = 0; i < NSMALLBINS; ++i) - do_check_smallbin(m, i); - for (i = 0; i < NTREEBINS; ++i) - do_check_treebin(m, i); - - if (m->dvsize != 0) { /* check dv chunk */ - do_check_any_chunk(m, m->dv); - assert(m->dvsize == chunksize(m->dv)); - assert(m->dvsize >= MIN_CHUNK_SIZE); - assert(bin_find(m, m->dv) == 0); - } - - if (m->top != 0) { /* check top chunk */ - do_check_top_chunk(m, m->top); - assert(m->topsize == chunksize(m->top)); - assert(m->topsize > 0); - assert(bin_find(m, m->top) == 0); - } - - total = traverse_and_check(m); - assert(total <= m->footprint); - assert(m->footprint <= m->max_footprint); -} -#endif /* DEBUG */ - -/* ----------------------------- statistics ------------------------------ */ - -#if !NO_MALLINFO -static struct mallinfo internal_mallinfo(mstate m) { - struct mallinfo nm = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; - if (!PREACTION(m)) { - check_malloc_state(m); - if (is_initialized(m)) { - size_t nfree = SIZE_T_ONE; /* top always free */ - size_t mfree = m->topsize + TOP_FOOT_SIZE; - size_t sum = mfree; - msegmentptr s = &m->seg; - while (s != 0) { - mchunkptr q = align_as_chunk(s->base); - while (segment_holds(s, q) && - q != m->top && q->head != FENCEPOST_HEAD) { - size_t sz = chunksize(q); - sum += sz; - if (!cinuse(q)) { - mfree += sz; - ++nfree; - } - q = next_chunk(q); - } - s = s->next; - } - - nm.arena = sum; - nm.ordblks = nfree; - nm.hblkhd = m->footprint - sum; - nm.usmblks = m->max_footprint; - nm.uordblks = m->footprint - mfree; - nm.fordblks = mfree; - nm.keepcost = m->topsize; - } - - POSTACTION(m); - } - return nm; -} -#endif /* !NO_MALLINFO */ - -static void internal_malloc_stats(mstate m) { - if (!PREACTION(m)) { - size_t maxfp = 0; - size_t fp = 0; - size_t used = 0; - check_malloc_state(m); - if (is_initialized(m)) { - msegmentptr s = &m->seg; - maxfp = m->max_footprint; - fp = m->footprint; - used = fp - (m->topsize + TOP_FOOT_SIZE); - - while (s != 0) { - mchunkptr q = align_as_chunk(s->base); - while (segment_holds(s, q) && - q != m->top && q->head != FENCEPOST_HEAD) { - if (!cinuse(q)) - used -= chunksize(q); - q = next_chunk(q); - } - s = s->next; - } - } - - fprintf(stderr, "max system bytes = %10lu\n", (unsigned long)(maxfp)); - fprintf(stderr, "system bytes = %10lu\n", (unsigned long)(fp)); - fprintf(stderr, "in use bytes = %10lu\n", (unsigned long)(used)); - - POSTACTION(m); - } -} - -/* ----------------------- Operations on smallbins ----------------------- */ - -/* - Various forms of linking and unlinking are defined as macros. Even - the ones for trees, which are very long but have very short typical - paths. This is ugly but reduces reliance on inlining support of - compilers. -*/ - -/* Link a free chunk into a smallbin */ -#define insert_small_chunk(M, P, S) {\ - bindex_t I = small_index(S);\ - mchunkptr B = smallbin_at(M, I);\ - mchunkptr F = B;\ - assert(S >= MIN_CHUNK_SIZE);\ - if (!smallmap_is_marked(M, I))\ - mark_smallmap(M, I);\ - else if (RTCHECK(ok_address(M, B->fd)))\ - F = B->fd;\ - else {\ - CORRUPTION_ERROR_ACTION(M);\ - }\ - B->fd = P;\ - F->bk = P;\ - P->fd = F;\ - P->bk = B;\ -} - -/* Unlink a chunk from a smallbin */ -#define unlink_small_chunk(M, P, S) {\ - mchunkptr F = P->fd;\ - mchunkptr B = P->bk;\ - bindex_t I = small_index(S);\ - assert(P != B);\ - assert(P != F);\ - assert(chunksize(P) == small_index2size(I));\ - if (F == B)\ - clear_smallmap(M, I);\ - else if (RTCHECK((F == smallbin_at(M,I) || ok_address(M, F)) &&\ - (B == smallbin_at(M,I) || ok_address(M, B)))) {\ - F->bk = B;\ - B->fd = F;\ - }\ - else {\ - CORRUPTION_ERROR_ACTION(M);\ - }\ -} - -/* Unlink the first chunk from a smallbin */ -#define unlink_first_small_chunk(M, B, P, I) {\ - mchunkptr F = P->fd;\ - assert(P != B);\ - assert(P != F);\ - assert(chunksize(P) == small_index2size(I));\ - if (B == F)\ - clear_smallmap(M, I);\ - else if (RTCHECK(ok_address(M, F))) {\ - B->fd = F;\ - F->bk = B;\ - }\ - else {\ - CORRUPTION_ERROR_ACTION(M);\ - }\ -} - -/* Replace dv node, binning the old one */ -/* Used only when dvsize known to be small */ -#define replace_dv(M, P, S) {\ - size_t DVS = M->dvsize;\ - if (DVS != 0) {\ - mchunkptr DV = M->dv;\ - assert(is_small(DVS));\ - insert_small_chunk(M, DV, DVS);\ - }\ - M->dvsize = S;\ - M->dv = P;\ -} - -/* ------------------------- Operations on trees ------------------------- */ - -/* Insert chunk into tree */ -#define insert_large_chunk(M, X, S) {\ - tbinptr* H;\ - bindex_t I;\ - compute_tree_index(S, I);\ - H = treebin_at(M, I);\ - X->index = I;\ - X->child[0] = X->child[1] = 0;\ - if (!treemap_is_marked(M, I)) {\ - mark_treemap(M, I);\ - *H = X;\ - X->parent = (tchunkptr)H;\ - X->fd = X->bk = X;\ - }\ - else {\ - tchunkptr T = *H;\ - size_t K = S << leftshift_for_tree_index(I);\ - for (;;) {\ - if (chunksize(T) != S) {\ - tchunkptr* C = &(T->child[(K >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]);\ - K <<= 1;\ - if (*C != 0)\ - T = *C;\ - else if (RTCHECK(ok_address(M, C))) {\ - *C = X;\ - X->parent = T;\ - X->fd = X->bk = X;\ - break;\ - }\ - else {\ - CORRUPTION_ERROR_ACTION(M);\ - break;\ - }\ - }\ - else {\ - tchunkptr F = T->fd;\ - if (RTCHECK(ok_address(M, T) && ok_address(M, F))) {\ - T->fd = F->bk = X;\ - X->fd = F;\ - X->bk = T;\ - X->parent = 0;\ - break;\ - }\ - else {\ - CORRUPTION_ERROR_ACTION(M);\ - break;\ - }\ - }\ - }\ - }\ -} - -/* - Unlink steps: - - 1. If x is a chained node, unlink it from its same-sized fd/bk links - and choose its bk node as its replacement. - 2. If x was the last node of its size, but not a leaf node, it must - be replaced with a leaf node (not merely one with an open left or - right), to make sure that lefts and rights of descendents - correspond properly to bit masks. We use the rightmost descendent - of x. We could use any other leaf, but this is easy to locate and - tends to counteract removal of leftmosts elsewhere, and so keeps - paths shorter than minimally guaranteed. This doesn't loop much - because on average a node in a tree is near the bottom. - 3. If x is the base of a chain (i.e., has parent links) relink - x's parent and children to x's replacement (or null if none). -*/ - -#define unlink_large_chunk(M, X) {\ - tchunkptr XP = X->parent;\ - tchunkptr R;\ - if (X->bk != X) {\ - tchunkptr F = X->fd;\ - R = X->bk;\ - if (RTCHECK(ok_address(M, F))) {\ - F->bk = R;\ - R->fd = F;\ - }\ - else {\ - CORRUPTION_ERROR_ACTION(M);\ - }\ - }\ - else {\ - tchunkptr* RP;\ - if (((R = *(RP = &(X->child[1]))) != 0) ||\ - ((R = *(RP = &(X->child[0]))) != 0)) {\ - tchunkptr* CP;\ - while ((*(CP = &(R->child[1])) != 0) ||\ - (*(CP = &(R->child[0])) != 0)) {\ - R = *(RP = CP);\ - }\ - if (RTCHECK(ok_address(M, RP)))\ - *RP = 0;\ - else {\ - CORRUPTION_ERROR_ACTION(M);\ - }\ - }\ - }\ - if (XP != 0) {\ - tbinptr* H = treebin_at(M, X->index);\ - if (X == *H) {\ - if ((*H = R) == 0) \ - clear_treemap(M, X->index);\ - }\ - else if (RTCHECK(ok_address(M, XP))) {\ - if (XP->child[0] == X) \ - XP->child[0] = R;\ - else \ - XP->child[1] = R;\ - }\ - else\ - CORRUPTION_ERROR_ACTION(M);\ - if (R != 0) {\ - if (RTCHECK(ok_address(M, R))) {\ - tchunkptr C0, C1;\ - R->parent = XP;\ - if ((C0 = X->child[0]) != 0) {\ - if (RTCHECK(ok_address(M, C0))) {\ - R->child[0] = C0;\ - C0->parent = R;\ - }\ - else\ - CORRUPTION_ERROR_ACTION(M);\ - }\ - if ((C1 = X->child[1]) != 0) {\ - if (RTCHECK(ok_address(M, C1))) {\ - R->child[1] = C1;\ - C1->parent = R;\ - }\ - else\ - CORRUPTION_ERROR_ACTION(M);\ - }\ - }\ - else\ - CORRUPTION_ERROR_ACTION(M);\ - }\ - }\ -} - -/* Relays to large vs small bin operations */ - -#define insert_chunk(M, P, S)\ - if (is_small(S)) insert_small_chunk(M, P, S)\ - else { tchunkptr TP = (tchunkptr)(P); insert_large_chunk(M, TP, S); } - -#define unlink_chunk(M, P, S)\ - if (is_small(S)) unlink_small_chunk(M, P, S)\ - else { tchunkptr TP = (tchunkptr)(P); unlink_large_chunk(M, TP); } - - -/* Relays to internal calls to malloc/free from realloc, memalign etc */ - -#if ONLY_MSPACES -#define internal_malloc(m, b) mspace_malloc(m, b) -#define internal_free(m, mem) mspace_free(m,mem); -#else /* ONLY_MSPACES */ -#if MSPACES -#define internal_malloc(m, b)\ - (m == gm)? dlmalloc(b) : mspace_malloc(m, b) -#define internal_free(m, mem)\ - if (m == gm) dlfree(mem); else mspace_free(m,mem); -#else /* MSPACES */ -#define internal_malloc(m, b) dlmalloc(b) -#define internal_free(m, mem) dlfree(mem) -#endif /* MSPACES */ -#endif /* ONLY_MSPACES */ - -/* ----------------------- Direct-mmapping chunks ----------------------- */ - -/* - Directly mmapped chunks are set up with an offset to the start of - the mmapped region stored in the prev_foot field of the chunk. This - allows reconstruction of the required argument to MUNMAP when freed, - and also allows adjustment of the returned chunk to meet alignment - requirements (especially in memalign). There is also enough space - allocated to hold a fake next chunk of size SIZE_T_SIZE to maintain - the PINUSE bit so frees can be checked. -*/ - -/* Malloc using mmap */ -static void* mmap_alloc(mstate m, size_t nb) { - size_t mmsize = granularity_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK); - if (mmsize > nb) { /* Check for wrap around 0 */ - char* mm = (char*)(DIRECT_MMAP(mmsize)); - if (mm != CMFAIL) { - size_t offset = align_offset(chunk2mem(mm)); - size_t psize = mmsize - offset - MMAP_FOOT_PAD; - mchunkptr p = (mchunkptr)(mm + offset); - p->prev_foot = offset | IS_MMAPPED_BIT; - (p)->head = (psize|CINUSE_BIT); - mark_inuse_foot(m, p, psize); - chunk_plus_offset(p, psize)->head = FENCEPOST_HEAD; - chunk_plus_offset(p, psize+SIZE_T_SIZE)->head = 0; - - if (mm < m->least_addr) - m->least_addr = mm; - if ((m->footprint += mmsize) > m->max_footprint) - m->max_footprint = m->footprint; - assert(is_aligned(chunk2mem(p))); - check_mmapped_chunk(m, p); - return chunk2mem(p); - } - } - return 0; -} - -/* Realloc using mmap */ -static mchunkptr mmap_resize(mstate m, mchunkptr oldp, size_t nb) { - size_t oldsize = chunksize(oldp); - if (is_small(nb)) /* Can't shrink mmap regions below small size */ - return 0; - /* Keep old chunk if big enough but not too big */ - if (oldsize >= nb + SIZE_T_SIZE && - (oldsize - nb) <= (mparams.granularity << 1)) - return oldp; - else { - size_t offset = oldp->prev_foot & ~IS_MMAPPED_BIT; - size_t oldmmsize = oldsize + offset + MMAP_FOOT_PAD; - size_t newmmsize = granularity_align(nb + SIX_SIZE_T_SIZES + - CHUNK_ALIGN_MASK); - char* cp = (char*)CALL_MREMAP((char*)oldp - offset, - oldmmsize, newmmsize, 1); - if (cp != CMFAIL) { - mchunkptr newp = (mchunkptr)(cp + offset); - size_t psize = newmmsize - offset - MMAP_FOOT_PAD; - newp->head = (psize|CINUSE_BIT); - mark_inuse_foot(m, newp, psize); - chunk_plus_offset(newp, psize)->head = FENCEPOST_HEAD; - chunk_plus_offset(newp, psize+SIZE_T_SIZE)->head = 0; - - if (cp < m->least_addr) - m->least_addr = cp; - if ((m->footprint += newmmsize - oldmmsize) > m->max_footprint) - m->max_footprint = m->footprint; - check_mmapped_chunk(m, newp); - return newp; - } - } - return 0; -} - -/* -------------------------- mspace management -------------------------- */ - -/* Initialize top chunk and its size */ -static void init_top(mstate m, mchunkptr p, size_t psize) { - /* Ensure alignment */ - size_t offset = align_offset(chunk2mem(p)); - p = (mchunkptr)((char*)p + offset); - psize -= offset; - - m->top = p; - m->topsize = psize; - p->head = psize | PINUSE_BIT; - /* set size of fake trailing chunk holding overhead space only once */ - chunk_plus_offset(p, psize)->head = TOP_FOOT_SIZE; - m->trim_check = mparams.trim_threshold; /* reset on each update */ -} - -/* Initialize bins for a new mstate that is otherwise zeroed out */ -static void init_bins(mstate m) { - /* Establish circular links for smallbins */ - bindex_t i; - for (i = 0; i < NSMALLBINS; ++i) { - sbinptr bin = smallbin_at(m,i); - bin->fd = bin->bk = bin; - } -} - -#if PROCEED_ON_ERROR - -/* default corruption action */ -static void reset_on_error(mstate m) { - int i; - ++malloc_corruption_error_count; - /* Reinitialize fields to forget about all memory */ - m->smallbins = m->treebins = 0; - m->dvsize = m->topsize = 0; - m->seg.base = 0; - m->seg.size = 0; - m->seg.next = 0; - m->top = m->dv = 0; - for (i = 0; i < NTREEBINS; ++i) - *treebin_at(m, i) = 0; - init_bins(m); -} -#endif /* PROCEED_ON_ERROR */ - -/* Allocate chunk and prepend remainder with chunk in successor base. */ -static void* prepend_alloc(mstate m, char* newbase, char* oldbase, - size_t nb) { - mchunkptr p = align_as_chunk(newbase); - mchunkptr oldfirst = align_as_chunk(oldbase); - size_t psize = (char*)oldfirst - (char*)p; - mchunkptr q = chunk_plus_offset(p, nb); - size_t qsize = psize - nb; - set_size_and_pinuse_of_inuse_chunk(m, p, nb); - - assert((char*)oldfirst > (char*)q); - assert(pinuse(oldfirst)); - assert(qsize >= MIN_CHUNK_SIZE); - - /* consolidate remainder with first chunk of old base */ - if (oldfirst == m->top) { - size_t tsize = m->topsize += qsize; - m->top = q; - q->head = tsize | PINUSE_BIT; - check_top_chunk(m, q); - } - else if (oldfirst == m->dv) { - size_t dsize = m->dvsize += qsize; - m->dv = q; - set_size_and_pinuse_of_free_chunk(q, dsize); - } - else { - if (!cinuse(oldfirst)) { - size_t nsize = chunksize(oldfirst); - unlink_chunk(m, oldfirst, nsize); - oldfirst = chunk_plus_offset(oldfirst, nsize); - qsize += nsize; - } - set_free_with_pinuse(q, qsize, oldfirst); - insert_chunk(m, q, qsize); - check_free_chunk(m, q); - } - - check_malloced_chunk(m, chunk2mem(p), nb); - return chunk2mem(p); -} - - -/* Add a segment to hold a new noncontiguous region */ -static void add_segment(mstate m, char* tbase, size_t tsize, flag_t mmapped) { - /* Determine locations and sizes of segment, fenceposts, old top */ - char* old_top = (char*)m->top; - msegmentptr oldsp = segment_holding(m, old_top); - char* old_end = oldsp->base + oldsp->size; - size_t ssize = pad_request(sizeof(struct malloc_segment)); - char* rawsp = old_end - (ssize + FOUR_SIZE_T_SIZES + CHUNK_ALIGN_MASK); - size_t offset = align_offset(chunk2mem(rawsp)); - char* asp = rawsp + offset; - char* csp = (asp < (old_top + MIN_CHUNK_SIZE))? old_top : asp; - mchunkptr sp = (mchunkptr)csp; - msegmentptr ss = (msegmentptr)(chunk2mem(sp)); - mchunkptr tnext = chunk_plus_offset(sp, ssize); - mchunkptr p = tnext; - int nfences = 0; - - /* reset top to new space */ - init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); - - /* Set up segment record */ - assert(is_aligned(ss)); - set_size_and_pinuse_of_inuse_chunk(m, sp, ssize); - *ss = m->seg; /* Push current record */ - m->seg.base = tbase; - m->seg.size = tsize; - set_segment_flags(&m->seg, mmapped); - m->seg.next = ss; - - /* Insert trailing fenceposts */ - for (;;) { - mchunkptr nextp = chunk_plus_offset(p, SIZE_T_SIZE); - p->head = FENCEPOST_HEAD; - ++nfences; - if ((char*)(&(nextp->head)) < old_end) - p = nextp; - else - break; - } - assert(nfences >= 2); - - /* Insert the rest of old top into a bin as an ordinary free chunk */ - if (csp != old_top) { - mchunkptr q = (mchunkptr)old_top; - size_t psize = csp - old_top; - mchunkptr tn = chunk_plus_offset(q, psize); - set_free_with_pinuse(q, psize, tn); - insert_chunk(m, q, psize); - } - - check_top_chunk(m, m->top); -} - -/* -------------------------- System allocation -------------------------- */ - -/* Get memory from system using MORECORE or MMAP */ -static void* sys_alloc(mstate m, size_t nb) { - char* tbase = CMFAIL; - size_t tsize = 0; - flag_t mmap_flag = 0; - - init_mparams(); - - /* Directly map large chunks */ - if (use_mmap(m) && nb >= mparams.mmap_threshold) { - void* mem = mmap_alloc(m, nb); - if (mem != 0) - return mem; - } - - /* - Try getting memory in any of three ways (in most-preferred to - least-preferred order): - 1. A call to MORECORE that can normally contiguously extend memory. - (disabled if not MORECORE_CONTIGUOUS or not HAVE_MORECORE or - or main space is mmapped or a previous contiguous call failed) - 2. A call to MMAP new space (disabled if not HAVE_MMAP). - Note that under the default settings, if MORECORE is unable to - fulfill a request, and HAVE_MMAP is true, then mmap is - used as a noncontiguous system allocator. This is a useful backup - strategy for systems with holes in address spaces -- in this case - sbrk cannot contiguously expand the heap, but mmap may be able to - find space. - 3. A call to MORECORE that cannot usually contiguously extend memory. - (disabled if not HAVE_MORECORE) - */ - - if (MORECORE_CONTIGUOUS && !use_noncontiguous(m)) { - char* br = CMFAIL; - msegmentptr ss = (m->top == 0)? 0 : segment_holding(m, (char*)m->top); - size_t asize = 0; - ACQUIRE_MORECORE_LOCK(); - - if (ss == 0) { /* First time through or recovery */ - char* base = (char*)CALL_MORECORE(0); - if (base != CMFAIL) { - asize = granularity_align(nb + TOP_FOOT_SIZE + SIZE_T_ONE); - /* Adjust to end on a page boundary */ - if (!is_page_aligned(base)) - asize += (page_align((size_t)base) - (size_t)base); - /* Can't call MORECORE if size is negative when treated as signed */ - if (asize < HALF_MAX_SIZE_T && - (br = (char*)(CALL_MORECORE(asize))) == base) { - tbase = base; - tsize = asize; - } - } - } - else { - /* Subtract out existing available top space from MORECORE request. */ - asize = granularity_align(nb - m->topsize + TOP_FOOT_SIZE + SIZE_T_ONE); - /* Use mem here only if it did continuously extend old space */ - if (asize < HALF_MAX_SIZE_T && - (br = (char*)(CALL_MORECORE(asize))) == ss->base+ss->size) { - tbase = br; - tsize = asize; - } - } - - if (tbase == CMFAIL) { /* Cope with partial failure */ - if (br != CMFAIL) { /* Try to use/extend the space we did get */ - if (asize < HALF_MAX_SIZE_T && - asize < nb + TOP_FOOT_SIZE + SIZE_T_ONE) { - size_t esize = granularity_align(nb + TOP_FOOT_SIZE + SIZE_T_ONE - asize); - if (esize < HALF_MAX_SIZE_T) { - char* end = (char*)CALL_MORECORE(esize); - if (end != CMFAIL) - asize += esize; - else { /* Can't use; try to release */ - (void)CALL_MORECORE(-asize); - br = CMFAIL; - } - } - } - } - if (br != CMFAIL) { /* Use the space we did get */ - tbase = br; - tsize = asize; - } - else - disable_contiguous(m); /* Don't try contiguous path in the future */ - } - - RELEASE_MORECORE_LOCK(); - } - - if (HAVE_MMAP && tbase == CMFAIL) { /* Try MMAP */ - size_t req = nb + TOP_FOOT_SIZE + SIZE_T_ONE; - size_t rsize = granularity_align(req); - if (rsize > nb) { /* Fail if wraps around zero */ - char* mp = (char*)(CALL_MMAP(rsize)); - if (mp != CMFAIL) { - tbase = mp; - tsize = rsize; - mmap_flag = IS_MMAPPED_BIT; - } - } - } - - if (HAVE_MORECORE && tbase == CMFAIL) { /* Try noncontiguous MORECORE */ - size_t asize = granularity_align(nb + TOP_FOOT_SIZE + SIZE_T_ONE); - if (asize < HALF_MAX_SIZE_T) { - char* br = CMFAIL; - char* end = CMFAIL; - ACQUIRE_MORECORE_LOCK(); - br = (char*)(CALL_MORECORE(asize)); - end = (char*)(CALL_MORECORE(0)); - RELEASE_MORECORE_LOCK(); - if (br != CMFAIL && end != CMFAIL && br < end) { - size_t ssize = end - br; - if (ssize > nb + TOP_FOOT_SIZE) { - tbase = br; - tsize = ssize; - } - } - } - } - - if (tbase != CMFAIL) { - - if ((m->footprint += tsize) > m->max_footprint) - m->max_footprint = m->footprint; - - if (!is_initialized(m)) { /* first-time initialization */ - m->seg.base = m->least_addr = tbase; - m->seg.size = tsize; - set_segment_flags(&m->seg, mmap_flag); - m->magic = mparams.magic; - init_bins(m); - if (is_global(m)) - init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); - else { - /* Offset top by embedded malloc_state */ - mchunkptr mn = next_chunk(mem2chunk(m)); - init_top(m, mn, (size_t)((tbase + tsize) - (char*)mn) -TOP_FOOT_SIZE); - } - } - - else { - /* Try to merge with an existing segment */ - msegmentptr sp = &m->seg; - while (sp != 0 && tbase != sp->base + sp->size) - sp = sp->next; - if (sp != 0 && - !is_extern_segment(sp) && - check_segment_merge(sp, tbase, tsize) && - (get_segment_flags(sp) & IS_MMAPPED_BIT) == mmap_flag && - segment_holds(sp, m->top)) { /* append */ - sp->size += tsize; - init_top(m, m->top, m->topsize + tsize); - } - else { - if (tbase < m->least_addr) - m->least_addr = tbase; - sp = &m->seg; - while (sp != 0 && sp->base != tbase + tsize) - sp = sp->next; - if (sp != 0 && - !is_extern_segment(sp) && - check_segment_merge(sp, tbase, tsize) && - (get_segment_flags(sp) & IS_MMAPPED_BIT) == mmap_flag) { - char* oldbase = sp->base; - sp->base = tbase; - sp->size += tsize; - return prepend_alloc(m, tbase, oldbase, nb); - } - else - add_segment(m, tbase, tsize, mmap_flag); - } - } - - if (nb < m->topsize) { /* Allocate from new or extended top space */ - size_t rsize = m->topsize -= nb; - mchunkptr p = m->top; - mchunkptr r = m->top = chunk_plus_offset(p, nb); - r->head = rsize | PINUSE_BIT; - set_size_and_pinuse_of_inuse_chunk(m, p, nb); - check_top_chunk(m, m->top); - check_malloced_chunk(m, chunk2mem(p), nb); - return chunk2mem(p); - } - } - - MALLOC_FAILURE_ACTION; - return 0; -} - -/* ----------------------- system deallocation -------------------------- */ - -/* Unmap and unlink any mmapped segments that don't contain used chunks */ -static size_t release_unused_segments(mstate m) { - size_t released = 0; - msegmentptr pred = &m->seg; - msegmentptr sp = pred->next; - while (sp != 0) { - char* base = sp->base; - size_t size = sp->size; - msegmentptr next = sp->next; - if (is_mmapped_segment(sp) && !is_extern_segment(sp)) { - mchunkptr p = align_as_chunk(base); - size_t psize = chunksize(p); - /* Can unmap if first chunk holds entire segment and not pinned */ - if (!cinuse(p) && (char*)p + psize >= base + size - TOP_FOOT_SIZE) { - tchunkptr tp = (tchunkptr)p; - assert(segment_holds(sp, (char*)sp)); - if (p == m->dv) { - m->dv = 0; - m->dvsize = 0; - } - else { - unlink_large_chunk(m, tp); - } - if (CALL_MUNMAP(base, size) == 0) { - released += size; - m->footprint -= size; - /* unlink obsoleted record */ - sp = pred; - sp->next = next; - } - else { /* back out if cannot unmap */ - insert_large_chunk(m, tp, psize); - } - } - } - pred = sp; - sp = next; - } - return released; -} - -static int sys_trim(mstate m, size_t pad) { - size_t released = 0; - if (pad < MAX_REQUEST && is_initialized(m)) { - pad += TOP_FOOT_SIZE; /* ensure enough room for segment overhead */ - - if (m->topsize > pad) { - /* Shrink top space in granularity-size units, keeping at least one */ - size_t unit = mparams.granularity; - size_t extra = ((m->topsize - pad + (unit - SIZE_T_ONE)) / unit - - SIZE_T_ONE) * unit; - msegmentptr sp = segment_holding(m, (char*)m->top); - - if (!is_extern_segment(sp)) { - if (is_mmapped_segment(sp)) { - if (HAVE_MMAP && - sp->size >= extra && - !has_segment_link(m, sp)) { /* can't shrink if pinned */ - size_t newsize = sp->size - extra; - /* Prefer mremap, fall back to munmap */ - if ((CALL_MREMAP(sp->base, sp->size, newsize, 0) != MFAIL) || - (CALL_MUNMAP(sp->base + newsize, extra) == 0)) { - released = extra; - } - } - } - else if (HAVE_MORECORE) { - if (extra >= HALF_MAX_SIZE_T) /* Avoid wrapping negative */ - extra = (HALF_MAX_SIZE_T) + SIZE_T_ONE - unit; - ACQUIRE_MORECORE_LOCK(); - { - /* Make sure end of memory is where we last set it. */ - char* old_br = (char*)(CALL_MORECORE(0)); - if (old_br == sp->base + sp->size) { - char* rel_br = (char*)(CALL_MORECORE(-extra)); - char* new_br = (char*)(CALL_MORECORE(0)); - if (rel_br != CMFAIL && new_br < old_br) - released = old_br - new_br; - } - } - RELEASE_MORECORE_LOCK(); - } - } - - if (released != 0) { - sp->size -= released; - m->footprint -= released; - init_top(m, m->top, m->topsize - released); - check_top_chunk(m, m->top); - } - } - - /* Unmap any unused mmapped segments */ - if (HAVE_MMAP) - released += release_unused_segments(m); - - /* On failure, disable autotrim to avoid repeated failed future calls */ - if (released == 0) - m->trim_check = MAX_SIZE_T; - } - - return (released != 0)? 1 : 0; -} - -/* ---------------------------- malloc support --------------------------- */ - -/* allocate a large request from the best fitting chunk in a treebin */ -static void* tmalloc_large(mstate m, size_t nb) { - tchunkptr v = 0; - size_t rsize = -nb; /* Unsigned negation */ - tchunkptr t; - bindex_t idx; - compute_tree_index(nb, idx); - - if ((t = *treebin_at(m, idx)) != 0) { - /* Traverse tree for this bin looking for node with size == nb */ - size_t sizebits = nb << leftshift_for_tree_index(idx); - tchunkptr rst = 0; /* The deepest untaken right subtree */ - for (;;) { - tchunkptr rt; - size_t trem = chunksize(t) - nb; - if (trem < rsize) { - v = t; - if ((rsize = trem) == 0) - break; - } - rt = t->child[1]; - t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; - if (rt != 0 && rt != t) - rst = rt; - if (t == 0) { - t = rst; /* set t to least subtree holding sizes > nb */ - break; - } - sizebits <<= 1; - } - } - - if (t == 0 && v == 0) { /* set t to root of next non-empty treebin */ - binmap_t leftbits = left_bits(idx2bit(idx)) & m->treemap; - if (leftbits != 0) { - bindex_t i; - binmap_t leastbit = least_bit(leftbits); - compute_bit2idx(leastbit, i); - t = *treebin_at(m, i); - } - } - - while (t != 0) { /* find smallest of tree or subtree */ - size_t trem = chunksize(t) - nb; - if (trem < rsize) { - rsize = trem; - v = t; - } - t = leftmost_child(t); - } - - /* If dv is a better fit, return 0 so malloc will use it */ - if (v != 0 && rsize < (size_t)(m->dvsize - nb)) { - if (RTCHECK(ok_address(m, v))) { /* split */ - mchunkptr r = chunk_plus_offset(v, nb); - assert(chunksize(v) == rsize + nb); - if (RTCHECK(ok_next(v, r))) { - unlink_large_chunk(m, v); - if (rsize < MIN_CHUNK_SIZE) - set_inuse_and_pinuse(m, v, (rsize + nb)); - else { - set_size_and_pinuse_of_inuse_chunk(m, v, nb); - set_size_and_pinuse_of_free_chunk(r, rsize); - insert_chunk(m, r, rsize); - } - return chunk2mem(v); - } - } - CORRUPTION_ERROR_ACTION(m); - } - return 0; -} - -/* allocate a small request from the best fitting chunk in a treebin */ -static void* tmalloc_small(mstate m, size_t nb) { - tchunkptr t, v; - size_t rsize; - bindex_t i; - binmap_t leastbit = least_bit(m->treemap); - compute_bit2idx(leastbit, i); - - v = t = *treebin_at(m, i); - rsize = chunksize(t) - nb; - - while ((t = leftmost_child(t)) != 0) { - size_t trem = chunksize(t) - nb; - if (trem < rsize) { - rsize = trem; - v = t; - } - } - - if (RTCHECK(ok_address(m, v))) { - mchunkptr r = chunk_plus_offset(v, nb); - assert(chunksize(v) == rsize + nb); - if (RTCHECK(ok_next(v, r))) { - unlink_large_chunk(m, v); - if (rsize < MIN_CHUNK_SIZE) - set_inuse_and_pinuse(m, v, (rsize + nb)); - else { - set_size_and_pinuse_of_inuse_chunk(m, v, nb); - set_size_and_pinuse_of_free_chunk(r, rsize); - replace_dv(m, r, rsize); - } - return chunk2mem(v); - } - } - - CORRUPTION_ERROR_ACTION(m); - return 0; -} - -/* --------------------------- realloc support --------------------------- */ - -static void* internal_realloc(mstate m, void* oldmem, size_t bytes) { - if (bytes >= MAX_REQUEST) { - MALLOC_FAILURE_ACTION; - return 0; - } - if (!PREACTION(m)) { - mchunkptr oldp = mem2chunk(oldmem); - size_t oldsize = chunksize(oldp); - mchunkptr next = chunk_plus_offset(oldp, oldsize); - mchunkptr newp = 0; - void* extra = 0; - - /* Try to either shrink or extend into top. Else malloc-copy-free */ - - if (RTCHECK(ok_address(m, oldp) && ok_cinuse(oldp) && - ok_next(oldp, next) && ok_pinuse(next))) { - size_t nb = request2size(bytes); - if (is_mmapped(oldp)) - newp = mmap_resize(m, oldp, nb); - else if (oldsize >= nb) { /* already big enough */ - size_t rsize = oldsize - nb; - newp = oldp; - if (rsize >= MIN_CHUNK_SIZE) { - mchunkptr remainder = chunk_plus_offset(newp, nb); - set_inuse(m, newp, nb); - set_inuse(m, remainder, rsize); - extra = chunk2mem(remainder); - } - } - else if (next == m->top && oldsize + m->topsize > nb) { - /* Expand into top */ - size_t newsize = oldsize + m->topsize; - size_t newtopsize = newsize - nb; - mchunkptr newtop = chunk_plus_offset(oldp, nb); - set_inuse(m, oldp, nb); - newtop->head = newtopsize |PINUSE_BIT; - m->top = newtop; - m->topsize = newtopsize; - newp = oldp; - } - } - else { - USAGE_ERROR_ACTION(m, oldmem); - POSTACTION(m); - return 0; - } - - POSTACTION(m); - - if (newp != 0) { - if (extra != 0) { - internal_free(m, extra); - } - check_inuse_chunk(m, newp); - return chunk2mem(newp); - } - else { - void* newmem = internal_malloc(m, bytes); - if (newmem != 0) { - size_t oc = oldsize - overhead_for(oldp); - memcpy(newmem, oldmem, (oc < bytes)? oc : bytes); - internal_free(m, oldmem); - } - return newmem; - } - } - return 0; -} - -/* --------------------------- memalign support -------------------------- */ - -static void* internal_memalign(mstate m, size_t alignment, size_t bytes) { - if (alignment <= MALLOC_ALIGNMENT) /* Can just use malloc */ - return internal_malloc(m, bytes); - if (alignment < MIN_CHUNK_SIZE) /* must be at least a minimum chunk size */ - alignment = MIN_CHUNK_SIZE; - if ((alignment & (alignment-SIZE_T_ONE)) != 0) {/* Ensure a power of 2 */ - size_t a = MALLOC_ALIGNMENT << 1; - while (a < alignment) a <<= 1; - alignment = a; - } - - if (bytes >= MAX_REQUEST - alignment) { - if (m != 0) { /* Test isn't needed but avoids compiler warning */ - MALLOC_FAILURE_ACTION; - } - } - else { - size_t nb = request2size(bytes); - size_t req = nb + alignment + MIN_CHUNK_SIZE - CHUNK_OVERHEAD; - char* mem = (char*)internal_malloc(m, req); - if (mem != 0) { - void* leader = 0; - void* trailer = 0; - mchunkptr p = mem2chunk(mem); - - if (PREACTION(m)) return 0; - if ((((size_t)(mem)) % alignment) != 0) { /* misaligned */ - /* - Find an aligned spot inside chunk. Since we need to give - back leading space in a chunk of at least MIN_CHUNK_SIZE, if - the first calculation places us at a spot with less than - MIN_CHUNK_SIZE leader, we can move to the next aligned spot. - We've allocated enough total room so that this is always - possible. - */ - char* br = (char*)mem2chunk((size_t)(((size_t)(mem + - alignment - - SIZE_T_ONE)) & - -alignment)); - char* pos = ((size_t)(br - (char*)(p)) >= MIN_CHUNK_SIZE)? - br : br+alignment; - mchunkptr newp = (mchunkptr)pos; - size_t leadsize = pos - (char*)(p); - size_t newsize = chunksize(p) - leadsize; - - if (is_mmapped(p)) { /* For mmapped chunks, just adjust offset */ - newp->prev_foot = p->prev_foot + leadsize; - newp->head = (newsize|CINUSE_BIT); - } - else { /* Otherwise, give back leader, use the rest */ - set_inuse(m, newp, newsize); - set_inuse(m, p, leadsize); - leader = chunk2mem(p); - } - p = newp; - } - - /* Give back spare room at the end */ - if (!is_mmapped(p)) { - size_t size = chunksize(p); - if (size > nb + MIN_CHUNK_SIZE) { - size_t remainder_size = size - nb; - mchunkptr remainder = chunk_plus_offset(p, nb); - set_inuse(m, p, nb); - set_inuse(m, remainder, remainder_size); - trailer = chunk2mem(remainder); - } - } - - assert (chunksize(p) >= nb); - assert((((size_t)(chunk2mem(p))) % alignment) == 0); - check_inuse_chunk(m, p); - POSTACTION(m); - if (leader != 0) { - internal_free(m, leader); - } - if (trailer != 0) { - internal_free(m, trailer); - } - return chunk2mem(p); - } - } - return 0; -} - -/* ------------------------ comalloc/coalloc support --------------------- */ - -static void** ialloc(mstate m, - size_t n_elements, - size_t* sizes, - int opts, - void* chunks[]) { - /* - This provides common support for independent_X routines, handling - all of the combinations that can result. - - The opts arg has: - bit 0 set if all elements are same size (using sizes[0]) - bit 1 set if elements should be zeroed - */ - - size_t element_size; /* chunksize of each element, if all same */ - size_t contents_size; /* total size of elements */ - size_t array_size; /* request size of pointer array */ - void* mem; /* malloced aggregate space */ - mchunkptr p; /* corresponding chunk */ - size_t remainder_size; /* remaining bytes while splitting */ - void** marray; /* either "chunks" or malloced ptr array */ - mchunkptr array_chunk; /* chunk for malloced ptr array */ - flag_t was_enabled; /* to disable mmap */ - size_t size; - size_t i; - - /* compute array length, if needed */ - if (chunks != 0) { - if (n_elements == 0) - return chunks; /* nothing to do */ - marray = chunks; - array_size = 0; - } - else { - /* if empty req, must still return chunk representing empty array */ - if (n_elements == 0) - return (void**)internal_malloc(m, 0); - marray = 0; - array_size = request2size(n_elements * (sizeof(void*))); - } - - /* compute total element size */ - if (opts & 0x1) { /* all-same-size */ - element_size = request2size(*sizes); - contents_size = n_elements * element_size; - } - else { /* add up all the sizes */ - element_size = 0; - contents_size = 0; - for (i = 0; i != n_elements; ++i) - contents_size += request2size(sizes[i]); - } - - size = contents_size + array_size; - - /* - Allocate the aggregate chunk. First disable direct-mmapping so - malloc won't use it, since we would not be able to later - free/realloc space internal to a segregated mmap region. - */ - was_enabled = use_mmap(m); - disable_mmap(m); - mem = internal_malloc(m, size - CHUNK_OVERHEAD); - if (was_enabled) - enable_mmap(m); - if (mem == 0) - return 0; - - if (PREACTION(m)) return 0; - p = mem2chunk(mem); - remainder_size = chunksize(p); - - assert(!is_mmapped(p)); - - if (opts & 0x2) { /* optionally clear the elements */ - memset((size_t*)mem, 0, remainder_size - SIZE_T_SIZE - array_size); - } - - /* If not provided, allocate the pointer array as final part of chunk */ - if (marray == 0) { - size_t array_chunk_size; - array_chunk = chunk_plus_offset(p, contents_size); - array_chunk_size = remainder_size - contents_size; - marray = (void**) (chunk2mem(array_chunk)); - set_size_and_pinuse_of_inuse_chunk(m, array_chunk, array_chunk_size); - remainder_size = contents_size; - } - - /* split out elements */ - for (i = 0; ; ++i) { - marray[i] = chunk2mem(p); - if (i != n_elements-1) { - if (element_size != 0) - size = element_size; - else - size = request2size(sizes[i]); - remainder_size -= size; - set_size_and_pinuse_of_inuse_chunk(m, p, size); - p = chunk_plus_offset(p, size); - } - else { /* the final element absorbs any overallocation slop */ - set_size_and_pinuse_of_inuse_chunk(m, p, remainder_size); - break; - } - } - -#if DEBUG - if (marray != chunks) { - /* final element must have exactly exhausted chunk */ - if (element_size != 0) { - assert(remainder_size == element_size); - } - else { - assert(remainder_size == request2size(sizes[i])); - } - check_inuse_chunk(m, mem2chunk(marray)); - } - for (i = 0; i != n_elements; ++i) - check_inuse_chunk(m, mem2chunk(marray[i])); - -#endif /* DEBUG */ - - POSTACTION(m); - return marray; -} - - -/* -------------------------- public routines ---------------------------- */ - -#if !ONLY_MSPACES - -void* dlmalloc(size_t bytes) { - /* - Basic algorithm: - If a small request (< 256 bytes minus per-chunk overhead): - 1. If one exists, use a remainderless chunk in associated smallbin. - (Remainderless means that there are too few excess bytes to - represent as a chunk.) - 2. If it is big enough, use the dv chunk, which is normally the - chunk adjacent to the one used for the most recent small request. - 3. If one exists, split the smallest available chunk in a bin, - saving remainder in dv. - 4. If it is big enough, use the top chunk. - 5. If available, get memory from system and use it - Otherwise, for a large request: - 1. Find the smallest available binned chunk that fits, and use it - if it is better fitting than dv chunk, splitting if necessary. - 2. If better fitting than any binned chunk, use the dv chunk. - 3. If it is big enough, use the top chunk. - 4. If request size >= mmap threshold, try to directly mmap this chunk. - 5. If available, get memory from system and use it - - The ugly goto's here ensure that postaction occurs along all paths. - */ - - if (!PREACTION(gm)) { - void* mem; - size_t nb; - if (bytes <= MAX_SMALL_REQUEST) { - bindex_t idx; - binmap_t smallbits; - nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes); - idx = small_index(nb); - smallbits = gm->smallmap >> idx; - - if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */ - mchunkptr b, p; - idx += ~smallbits & 1; /* Uses next bin if idx empty */ - b = smallbin_at(gm, idx); - p = b->fd; - assert(chunksize(p) == small_index2size(idx)); - unlink_first_small_chunk(gm, b, p, idx); - set_inuse_and_pinuse(gm, p, small_index2size(idx)); - mem = chunk2mem(p); - check_malloced_chunk(gm, mem, nb); - goto postaction; - } - - else if (nb > gm->dvsize) { - if (smallbits != 0) { /* Use chunk in next nonempty smallbin */ - mchunkptr b, p, r; - size_t rsize; - bindex_t i; - binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx)); - binmap_t leastbit = least_bit(leftbits); - compute_bit2idx(leastbit, i); - b = smallbin_at(gm, i); - p = b->fd; - assert(chunksize(p) == small_index2size(i)); - unlink_first_small_chunk(gm, b, p, i); - rsize = small_index2size(i) - nb; - /* Fit here cannot be remainderless if 4byte sizes */ - if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE) - set_inuse_and_pinuse(gm, p, small_index2size(i)); - else { - set_size_and_pinuse_of_inuse_chunk(gm, p, nb); - r = chunk_plus_offset(p, nb); - set_size_and_pinuse_of_free_chunk(r, rsize); - replace_dv(gm, r, rsize); - } - mem = chunk2mem(p); - check_malloced_chunk(gm, mem, nb); - goto postaction; - } - - else if (gm->treemap != 0 && (mem = tmalloc_small(gm, nb)) != 0) { - check_malloced_chunk(gm, mem, nb); - goto postaction; - } - } - } - else if (bytes >= MAX_REQUEST) - nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */ - else { - nb = pad_request(bytes); - if (gm->treemap != 0 && (mem = tmalloc_large(gm, nb)) != 0) { - check_malloced_chunk(gm, mem, nb); - goto postaction; - } - } - - if (nb <= gm->dvsize) { - size_t rsize = gm->dvsize - nb; - mchunkptr p = gm->dv; - if (rsize >= MIN_CHUNK_SIZE) { /* split dv */ - mchunkptr r = gm->dv = chunk_plus_offset(p, nb); - gm->dvsize = rsize; - set_size_and_pinuse_of_free_chunk(r, rsize); - set_size_and_pinuse_of_inuse_chunk(gm, p, nb); - } - else { /* exhaust dv */ - size_t dvs = gm->dvsize; - gm->dvsize = 0; - gm->dv = 0; - set_inuse_and_pinuse(gm, p, dvs); - } - mem = chunk2mem(p); - check_malloced_chunk(gm, mem, nb); - goto postaction; - } - - else if (nb < gm->topsize) { /* Split top */ - size_t rsize = gm->topsize -= nb; - mchunkptr p = gm->top; - mchunkptr r = gm->top = chunk_plus_offset(p, nb); - r->head = rsize | PINUSE_BIT; - set_size_and_pinuse_of_inuse_chunk(gm, p, nb); - mem = chunk2mem(p); - check_top_chunk(gm, gm->top); - check_malloced_chunk(gm, mem, nb); - goto postaction; - } - - mem = sys_alloc(gm, nb); - - postaction: - POSTACTION(gm); - return mem; - } - - return 0; -} - -void dlfree(void* mem) { - /* - Consolidate freed chunks with preceding or succeeding bordering - free chunks, if they exist, and then place in a bin. Intermixed - with special cases for top, dv, mmapped chunks, and usage errors. - */ - - if (mem != 0) { - mchunkptr p = mem2chunk(mem); -#if FOOTERS - mstate fm = get_mstate_for(p); - if (!ok_magic(fm)) { - USAGE_ERROR_ACTION(fm, p); - return; - } -#else /* FOOTERS */ -#define fm gm -#endif /* FOOTERS */ - if (!PREACTION(fm)) { - check_inuse_chunk(fm, p); - if (RTCHECK(ok_address(fm, p) && ok_cinuse(p))) { - size_t psize = chunksize(p); - mchunkptr next = chunk_plus_offset(p, psize); - if (!pinuse(p)) { - size_t prevsize = p->prev_foot; - if ((prevsize & IS_MMAPPED_BIT) != 0) { - prevsize &= ~IS_MMAPPED_BIT; - psize += prevsize + MMAP_FOOT_PAD; - if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) - fm->footprint -= psize; - goto postaction; - } - else { - mchunkptr prev = chunk_minus_offset(p, prevsize); - psize += prevsize; - p = prev; - if (RTCHECK(ok_address(fm, prev))) { /* consolidate backward */ - if (p != fm->dv) { - unlink_chunk(fm, p, prevsize); - } - else if ((next->head & INUSE_BITS) == INUSE_BITS) { - fm->dvsize = psize; - set_free_with_pinuse(p, psize, next); - goto postaction; - } - } - else - goto erroraction; - } - } - - if (RTCHECK(ok_next(p, next) && ok_pinuse(next))) { - if (!cinuse(next)) { /* consolidate forward */ - if (next == fm->top) { - size_t tsize = fm->topsize += psize; - fm->top = p; - p->head = tsize | PINUSE_BIT; - if (p == fm->dv) { - fm->dv = 0; - fm->dvsize = 0; - } - if (should_trim(fm, tsize)) - sys_trim(fm, 0); - goto postaction; - } - else if (next == fm->dv) { - size_t dsize = fm->dvsize += psize; - fm->dv = p; - set_size_and_pinuse_of_free_chunk(p, dsize); - goto postaction; - } - else { - size_t nsize = chunksize(next); - psize += nsize; - unlink_chunk(fm, next, nsize); - set_size_and_pinuse_of_free_chunk(p, psize); - if (p == fm->dv) { - fm->dvsize = psize; - goto postaction; - } - } - } - else - set_free_with_pinuse(p, psize, next); - insert_chunk(fm, p, psize); - check_free_chunk(fm, p); - goto postaction; - } - } - erroraction: - USAGE_ERROR_ACTION(fm, p); - postaction: - POSTACTION(fm); - } - } -#if !FOOTERS -#undef fm -#endif /* FOOTERS */ -} - -void* dlcalloc(size_t n_elements, size_t elem_size) { - void* mem; - size_t req = 0; - if (n_elements != 0) { - req = n_elements * elem_size; - if (((n_elements | elem_size) & ~(size_t)0xffff) && - (req / n_elements != elem_size)) - req = MAX_SIZE_T; /* force downstream failure on overflow */ - } - mem = dlmalloc(req); - if (mem != 0 && calloc_must_clear(mem2chunk(mem))) - memset(mem, 0, req); - return mem; -} - -void* dlrealloc(void* oldmem, size_t bytes) { - if (oldmem == 0) - return dlmalloc(bytes); -#ifdef REALLOC_ZERO_BYTES_FREES - if (bytes == 0) { - dlfree(oldmem); - return 0; - } -#endif /* REALLOC_ZERO_BYTES_FREES */ - else { -#if ! FOOTERS - mstate m = gm; -#else /* FOOTERS */ - mstate m = get_mstate_for(mem2chunk(oldmem)); - if (!ok_magic(m)) { - USAGE_ERROR_ACTION(m, oldmem); - return 0; - } -#endif /* FOOTERS */ - return internal_realloc(m, oldmem, bytes); - } -} - -void* dlmemalign(size_t alignment, size_t bytes) { - return internal_memalign(gm, alignment, bytes); -} - -void** dlindependent_calloc(size_t n_elements, size_t elem_size, - void* chunks[]) { - size_t sz = elem_size; /* serves as 1-element array */ - return ialloc(gm, n_elements, &sz, 3, chunks); -} - -void** dlindependent_comalloc(size_t n_elements, size_t sizes[], - void* chunks[]) { - return ialloc(gm, n_elements, sizes, 0, chunks); -} - -void* dlvalloc(size_t bytes) { - size_t pagesz; - init_mparams(); - pagesz = mparams.page_size; - return dlmemalign(pagesz, bytes); -} - -void* dlpvalloc(size_t bytes) { - size_t pagesz; - init_mparams(); - pagesz = mparams.page_size; - return dlmemalign(pagesz, (bytes + pagesz - SIZE_T_ONE) & ~(pagesz - SIZE_T_ONE)); -} - -int dlmalloc_trim(size_t pad) { - int result = 0; - if (!PREACTION(gm)) { - result = sys_trim(gm, pad); - POSTACTION(gm); - } - return result; -} - -size_t dlmalloc_footprint(void) { - return gm->footprint; -} - -size_t dlmalloc_max_footprint(void) { - return gm->max_footprint; -} - -#if !NO_MALLINFO -struct mallinfo dlmallinfo(void) { - return internal_mallinfo(gm); -} -#endif /* NO_MALLINFO */ - -void dlmalloc_stats() { - internal_malloc_stats(gm); -} - -size_t dlmalloc_usable_size(void* mem) { - if (mem != 0) { - mchunkptr p = mem2chunk(mem); - if (cinuse(p)) - return chunksize(p) - overhead_for(p); - } - return 0; -} - -int dlmallopt(int param_number, int value) { - return change_mparam(param_number, value); -} - -#endif /* !ONLY_MSPACES */ - -/* ----------------------------- user mspaces ---------------------------- */ - -#if MSPACES - -static mstate init_user_mstate(char* tbase, size_t tsize) { - size_t msize = pad_request(sizeof(struct malloc_state)); - mchunkptr mn; - mchunkptr msp = align_as_chunk(tbase); - mstate m = (mstate)(chunk2mem(msp)); - memset(m, 0, msize); - INITIAL_LOCK(&m->mutex); - msp->head = (msize|PINUSE_BIT|CINUSE_BIT); - m->seg.base = m->least_addr = tbase; - m->seg.size = m->footprint = m->max_footprint = tsize; - m->magic = mparams.magic; - m->mflags = mparams.default_mflags; - disable_contiguous(m); - init_bins(m); - mn = next_chunk(mem2chunk(m)); - init_top(m, mn, (size_t)((tbase + tsize) - (char*)mn) - TOP_FOOT_SIZE); - check_top_chunk(m, m->top); - return m; -} - -mspace create_mspace(size_t capacity, int locked) { - mstate m = 0; - size_t msize = pad_request(sizeof(struct malloc_state)); - init_mparams(); /* Ensure pagesize etc initialized */ - - if (capacity < (size_t) -(msize + TOP_FOOT_SIZE + mparams.page_size)) { - size_t rs = ((capacity == 0)? mparams.granularity : - (capacity + TOP_FOOT_SIZE + msize)); - size_t tsize = granularity_align(rs); - char* tbase = (char*)(CALL_MMAP(tsize)); - if (tbase != CMFAIL) { - m = init_user_mstate(tbase, tsize); - set_segment_flags(&m->seg, IS_MMAPPED_BIT); - set_lock(m, locked); - } - } - return (mspace)m; -} - -mspace create_mspace_with_base(void* base, size_t capacity, int locked) { - mstate m = 0; - size_t msize = pad_request(sizeof(struct malloc_state)); - init_mparams(); /* Ensure pagesize etc initialized */ - - if (capacity > msize + TOP_FOOT_SIZE && - capacity < (size_t) -(msize + TOP_FOOT_SIZE + mparams.page_size)) { - m = init_user_mstate((char*)base, capacity); - set_segment_flags(&m->seg, EXTERN_BIT); - set_lock(m, locked); - } - return (mspace)m; -} - -size_t destroy_mspace(mspace msp) { - size_t freed = 0; - mstate ms = (mstate)msp; - if (ok_magic(ms)) { - msegmentptr sp = &ms->seg; - while (sp != 0) { - char* base = sp->base; - size_t size = sp->size; - flag_t flag = get_segment_flags(sp); - sp = sp->next; - if ((flag & IS_MMAPPED_BIT) && !(flag & EXTERN_BIT) && - CALL_MUNMAP(base, size) == 0) - freed += size; - } - } - else { - USAGE_ERROR_ACTION(ms,ms); - } - return freed; -} - -/* - mspace versions of routines are near-clones of the global - versions. This is not so nice but better than the alternatives. -*/ - - -void* mspace_malloc(mspace msp, size_t bytes) { - mstate ms = (mstate)msp; - if (!ok_magic(ms)) { - USAGE_ERROR_ACTION(ms,ms); - return 0; - } - if (!PREACTION(ms)) { - void* mem; - size_t nb; - if (bytes <= MAX_SMALL_REQUEST) { - bindex_t idx; - binmap_t smallbits; - nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes); - idx = small_index(nb); - smallbits = ms->smallmap >> idx; - - if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */ - mchunkptr b, p; - idx += ~smallbits & 1; /* Uses next bin if idx empty */ - b = smallbin_at(ms, idx); - p = b->fd; - assert(chunksize(p) == small_index2size(idx)); - unlink_first_small_chunk(ms, b, p, idx); - set_inuse_and_pinuse(ms, p, small_index2size(idx)); - mem = chunk2mem(p); - check_malloced_chunk(ms, mem, nb); - goto postaction; - } - - else if (nb > ms->dvsize) { - if (smallbits != 0) { /* Use chunk in next nonempty smallbin */ - mchunkptr b, p, r; - size_t rsize; - bindex_t i; - binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx)); - binmap_t leastbit = least_bit(leftbits); - compute_bit2idx(leastbit, i); - b = smallbin_at(ms, i); - p = b->fd; - assert(chunksize(p) == small_index2size(i)); - unlink_first_small_chunk(ms, b, p, i); - rsize = small_index2size(i) - nb; - /* Fit here cannot be remainderless if 4byte sizes */ - if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE) - set_inuse_and_pinuse(ms, p, small_index2size(i)); - else { - set_size_and_pinuse_of_inuse_chunk(ms, p, nb); - r = chunk_plus_offset(p, nb); - set_size_and_pinuse_of_free_chunk(r, rsize); - replace_dv(ms, r, rsize); - } - mem = chunk2mem(p); - check_malloced_chunk(ms, mem, nb); - goto postaction; - } - - else if (ms->treemap != 0 && (mem = tmalloc_small(ms, nb)) != 0) { - check_malloced_chunk(ms, mem, nb); - goto postaction; - } - } - } - else if (bytes >= MAX_REQUEST) - nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */ - else { - nb = pad_request(bytes); - if (ms->treemap != 0 && (mem = tmalloc_large(ms, nb)) != 0) { - check_malloced_chunk(ms, mem, nb); - goto postaction; - } - } - - if (nb <= ms->dvsize) { - size_t rsize = ms->dvsize - nb; - mchunkptr p = ms->dv; - if (rsize >= MIN_CHUNK_SIZE) { /* split dv */ - mchunkptr r = ms->dv = chunk_plus_offset(p, nb); - ms->dvsize = rsize; - set_size_and_pinuse_of_free_chunk(r, rsize); - set_size_and_pinuse_of_inuse_chunk(ms, p, nb); - } - else { /* exhaust dv */ - size_t dvs = ms->dvsize; - ms->dvsize = 0; - ms->dv = 0; - set_inuse_and_pinuse(ms, p, dvs); - } - mem = chunk2mem(p); - check_malloced_chunk(ms, mem, nb); - goto postaction; - } - - else if (nb < ms->topsize) { /* Split top */ - size_t rsize = ms->topsize -= nb; - mchunkptr p = ms->top; - mchunkptr r = ms->top = chunk_plus_offset(p, nb); - r->head = rsize | PINUSE_BIT; - set_size_and_pinuse_of_inuse_chunk(ms, p, nb); - mem = chunk2mem(p); - check_top_chunk(ms, ms->top); - check_malloced_chunk(ms, mem, nb); - goto postaction; - } - - mem = sys_alloc(ms, nb); - - postaction: - POSTACTION(ms); - return mem; - } - - return 0; -} - -void mspace_free(mspace msp, void* mem) { - if (mem != 0) { - mchunkptr p = mem2chunk(mem); -#if FOOTERS - mstate fm = get_mstate_for(p); -#else /* FOOTERS */ - mstate fm = (mstate)msp; -#endif /* FOOTERS */ - if (!ok_magic(fm)) { - USAGE_ERROR_ACTION(fm, p); - return; - } - if (!PREACTION(fm)) { - check_inuse_chunk(fm, p); - if (RTCHECK(ok_address(fm, p) && ok_cinuse(p))) { - size_t psize = chunksize(p); - mchunkptr next = chunk_plus_offset(p, psize); - if (!pinuse(p)) { - size_t prevsize = p->prev_foot; - if ((prevsize & IS_MMAPPED_BIT) != 0) { - prevsize &= ~IS_MMAPPED_BIT; - psize += prevsize + MMAP_FOOT_PAD; - if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) - fm->footprint -= psize; - goto postaction; - } - else { - mchunkptr prev = chunk_minus_offset(p, prevsize); - psize += prevsize; - p = prev; - if (RTCHECK(ok_address(fm, prev))) { /* consolidate backward */ - if (p != fm->dv) { - unlink_chunk(fm, p, prevsize); - } - else if ((next->head & INUSE_BITS) == INUSE_BITS) { - fm->dvsize = psize; - set_free_with_pinuse(p, psize, next); - goto postaction; - } - } - else - goto erroraction; - } - } - - if (RTCHECK(ok_next(p, next) && ok_pinuse(next))) { - if (!cinuse(next)) { /* consolidate forward */ - if (next == fm->top) { - size_t tsize = fm->topsize += psize; - fm->top = p; - p->head = tsize | PINUSE_BIT; - if (p == fm->dv) { - fm->dv = 0; - fm->dvsize = 0; - } - if (should_trim(fm, tsize)) - sys_trim(fm, 0); - goto postaction; - } - else if (next == fm->dv) { - size_t dsize = fm->dvsize += psize; - fm->dv = p; - set_size_and_pinuse_of_free_chunk(p, dsize); - goto postaction; - } - else { - size_t nsize = chunksize(next); - psize += nsize; - unlink_chunk(fm, next, nsize); - set_size_and_pinuse_of_free_chunk(p, psize); - if (p == fm->dv) { - fm->dvsize = psize; - goto postaction; - } - } - } - else - set_free_with_pinuse(p, psize, next); - insert_chunk(fm, p, psize); - check_free_chunk(fm, p); - goto postaction; - } - } - erroraction: - USAGE_ERROR_ACTION(fm, p); - postaction: - POSTACTION(fm); - } - } -} - -void* mspace_calloc(mspace msp, size_t n_elements, size_t elem_size) { - void* mem; - size_t req = 0; - mstate ms = (mstate)msp; - if (!ok_magic(ms)) { - USAGE_ERROR_ACTION(ms,ms); - return 0; - } - if (n_elements != 0) { - req = n_elements * elem_size; - if (((n_elements | elem_size) & ~(size_t)0xffff) && - (req / n_elements != elem_size)) - req = MAX_SIZE_T; /* force downstream failure on overflow */ - } - mem = internal_malloc(ms, req); - if (mem != 0 && calloc_must_clear(mem2chunk(mem))) - memset(mem, 0, req); - return mem; -} - -void* mspace_realloc(mspace msp, void* oldmem, size_t bytes) { - if (oldmem == 0) - return mspace_malloc(msp, bytes); -#ifdef REALLOC_ZERO_BYTES_FREES - if (bytes == 0) { - mspace_free(msp, oldmem); - return 0; - } -#endif /* REALLOC_ZERO_BYTES_FREES */ - else { -#if FOOTERS - mchunkptr p = mem2chunk(oldmem); - mstate ms = get_mstate_for(p); -#else /* FOOTERS */ - mstate ms = (mstate)msp; -#endif /* FOOTERS */ - if (!ok_magic(ms)) { - USAGE_ERROR_ACTION(ms,ms); - return 0; - } - return internal_realloc(ms, oldmem, bytes); - } -} - -void* mspace_memalign(mspace msp, size_t alignment, size_t bytes) { - mstate ms = (mstate)msp; - if (!ok_magic(ms)) { - USAGE_ERROR_ACTION(ms,ms); - return 0; - } - return internal_memalign(ms, alignment, bytes); -} - -void** mspace_independent_calloc(mspace msp, size_t n_elements, - size_t elem_size, void* chunks[]) { - size_t sz = elem_size; /* serves as 1-element array */ - mstate ms = (mstate)msp; - if (!ok_magic(ms)) { - USAGE_ERROR_ACTION(ms,ms); - return 0; - } - return ialloc(ms, n_elements, &sz, 3, chunks); -} - -void** mspace_independent_comalloc(mspace msp, size_t n_elements, - size_t sizes[], void* chunks[]) { - mstate ms = (mstate)msp; - if (!ok_magic(ms)) { - USAGE_ERROR_ACTION(ms,ms); - return 0; - } - return ialloc(ms, n_elements, sizes, 0, chunks); -} - -int mspace_trim(mspace msp, size_t pad) { - int result = 0; - mstate ms = (mstate)msp; - if (ok_magic(ms)) { - if (!PREACTION(ms)) { - result = sys_trim(ms, pad); - POSTACTION(ms); - } - } - else { - USAGE_ERROR_ACTION(ms,ms); - } - return result; -} - -void mspace_malloc_stats(mspace msp) { - mstate ms = (mstate)msp; - if (ok_magic(ms)) { - internal_malloc_stats(ms); - } - else { - USAGE_ERROR_ACTION(ms,ms); - } -} - -size_t mspace_footprint(mspace msp) { - size_t result; - mstate ms = (mstate)msp; - if (ok_magic(ms)) { - result = ms->footprint; - } - USAGE_ERROR_ACTION(ms,ms); - return result; -} - - -size_t mspace_max_footprint(mspace msp) { - size_t result; - mstate ms = (mstate)msp; - if (ok_magic(ms)) { - result = ms->max_footprint; - } - USAGE_ERROR_ACTION(ms,ms); - return result; -} - - -#if !NO_MALLINFO -struct mallinfo mspace_mallinfo(mspace msp) { - mstate ms = (mstate)msp; - if (!ok_magic(ms)) { - USAGE_ERROR_ACTION(ms,ms); - } - return internal_mallinfo(ms); -} -#endif /* NO_MALLINFO */ - -int mspace_mallopt(int param_number, int value) { - return change_mparam(param_number, value); -} - -#endif /* MSPACES */ - -/* -------------------- Alternative MORECORE functions ------------------- */ - -/* - Guidelines for creating a custom version of MORECORE: - - * For best performance, MORECORE should allocate in multiples of pagesize. - * MORECORE may allocate more memory than requested. (Or even less, - but this will usually result in a malloc failure.) - * MORECORE must not allocate memory when given argument zero, but - instead return one past the end address of memory from previous - nonzero call. - * For best performance, consecutive calls to MORECORE with positive - arguments should return increasing addresses, indicating that - space has been contiguously extended. - * Even though consecutive calls to MORECORE need not return contiguous - addresses, it must be OK for malloc'ed chunks to span multiple - regions in those cases where they do happen to be contiguous. - * MORECORE need not handle negative arguments -- it may instead - just return MFAIL when given negative arguments. - Negative arguments are always multiples of pagesize. MORECORE - must not misinterpret negative args as large positive unsigned - args. You can suppress all such calls from even occurring by defining - MORECORE_CANNOT_TRIM, - - As an example alternative MORECORE, here is a custom allocator - kindly contributed for pre-OSX macOS. It uses virtually but not - necessarily physically contiguous non-paged memory (locked in, - present and won't get swapped out). You can use it by uncommenting - this section, adding some #includes, and setting up the appropriate - defines above: - - #define MORECORE osMoreCore - - There is also a shutdown routine that should somehow be called for - cleanup upon program exit. - - #define MAX_POOL_ENTRIES 100 - #define MINIMUM_MORECORE_SIZE (64 * 1024U) - static int next_os_pool; - void *our_os_pools[MAX_POOL_ENTRIES]; - - void *osMoreCore(int size) - { - void *ptr = 0; - static void *sbrk_top = 0; - - if (size > 0) - { - if (size < MINIMUM_MORECORE_SIZE) - size = MINIMUM_MORECORE_SIZE; - if (CurrentExecutionLevel() == kTaskLevel) - ptr = PoolAllocateResident(size + RM_PAGE_SIZE, 0); - if (ptr == 0) - { - return (void *) MFAIL; - } - // save ptrs so they can be freed during cleanup - our_os_pools[next_os_pool] = ptr; - next_os_pool++; - ptr = (void *) ((((size_t) ptr) + RM_PAGE_MASK) & ~RM_PAGE_MASK); - sbrk_top = (char *) ptr + size; - return ptr; - } - else if (size < 0) - { - // we don't currently support shrink behavior - return (void *) MFAIL; - } - else - { - return sbrk_top; - } - } - - // cleanup any allocated memory pools - // called as last thing before shutting down driver - - void osCleanupMem(void) - { - void **ptr; - - for (ptr = our_os_pools; ptr < &our_os_pools[MAX_POOL_ENTRIES]; ptr++) - if (*ptr) - { - PoolDeallocate(*ptr); - *ptr = 0; - } - } - -*/ - - -/* ----------------------------------------------------------------------- -History: - V2.8.3 Thu Sep 22 11:16:32 2005 Doug Lea (dl at gee) - * Add max_footprint functions - * Ensure all appropriate literals are size_t - * Fix conditional compilation problem for some #define settings - * Avoid concatenating segments with the one provided - in create_mspace_with_base - * Rename some variables to avoid compiler shadowing warnings - * Use explicit lock initialization. - * Better handling of sbrk interference. - * Simplify and fix segment insertion, trimming and mspace_destroy - * Reinstate REALLOC_ZERO_BYTES_FREES option from 2.7.x - * Thanks especially to Dennis Flanagan for help on these. - - V2.8.2 Sun Jun 12 16:01:10 2005 Doug Lea (dl at gee) - * Fix memalign brace error. - - V2.8.1 Wed Jun 8 16:11:46 2005 Doug Lea (dl at gee) - * Fix improper #endif nesting in C++ - * Add explicit casts needed for C++ - - V2.8.0 Mon May 30 14:09:02 2005 Doug Lea (dl at gee) - * Use trees for large bins - * Support mspaces - * Use segments to unify sbrk-based and mmap-based system allocation, - removing need for emulation on most platforms without sbrk. - * Default safety checks - * Optional footer checks. Thanks to William Robertson for the idea. - * Internal code refactoring - * Incorporate suggestions and platform-specific changes. - Thanks to Dennis Flanagan, Colin Plumb, Niall Douglas, - Aaron Bachmann, Emery Berger, and others. - * Speed up non-fastbin processing enough to remove fastbins. - * Remove useless cfree() to avoid conflicts with other apps. - * Remove internal memcpy, memset. Compilers handle builtins better. - * Remove some options that no one ever used and rename others. - - V2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) - * Fix malloc_state bitmap array misdeclaration - - V2.7.1 Thu Jul 25 10:58:03 2002 Doug Lea (dl at gee) - * Allow tuning of FIRST_SORTED_BIN_SIZE - * Use PTR_UINT as type for all ptr->int casts. Thanks to John Belmonte. - * Better detection and support for non-contiguousness of MORECORE. - Thanks to Andreas Mueller, Conal Walsh, and Wolfram Gloger - * Bypass most of malloc if no frees. Thanks To Emery Berger. - * Fix freeing of old top non-contiguous chunk im sysmalloc. - * Raised default trim and map thresholds to 256K. - * Fix mmap-related #defines. Thanks to Lubos Lunak. - * Fix copy macros; added LACKS_FCNTL_H. Thanks to Neal Walfield. - * Branch-free bin calculation - * Default trim and mmap thresholds now 256K. - - V2.7.0 Sun Mar 11 14:14:06 2001 Doug Lea (dl at gee) - * Introduce independent_comalloc and independent_calloc. - Thanks to Michael Pachos for motivation and help. - * Make optional .h file available - * Allow > 2GB requests on 32bit systems. - * new WIN32 sbrk, mmap, munmap, lock code from <Walter@GeNeSys-e.de>. - Thanks also to Andreas Mueller <a.mueller at paradatec.de>, - and Anonymous. - * Allow override of MALLOC_ALIGNMENT (Thanks to Ruud Waij for - helping test this.) - * memalign: check alignment arg - * realloc: don't try to shift chunks backwards, since this - leads to more fragmentation in some programs and doesn't - seem to help in any others. - * Collect all cases in malloc requiring system memory into sysmalloc - * Use mmap as backup to sbrk - * Place all internal state in malloc_state - * Introduce fastbins (although similar to 2.5.1) - * Many minor tunings and cosmetic improvements - * Introduce USE_PUBLIC_MALLOC_WRAPPERS, USE_MALLOC_LOCK - * Introduce MALLOC_FAILURE_ACTION, MORECORE_CONTIGUOUS - Thanks to Tony E. Bennett <tbennett@nvidia.com> and others. - * Include errno.h to support default failure action. - - V2.6.6 Sun Dec 5 07:42:19 1999 Doug Lea (dl at gee) - * return null for negative arguments - * Added Several WIN32 cleanups from Martin C. Fong <mcfong at yahoo.com> - * Add 'LACKS_SYS_PARAM_H' for those systems without 'sys/param.h' - (e.g. WIN32 platforms) - * Cleanup header file inclusion for WIN32 platforms - * Cleanup code to avoid Microsoft Visual C++ compiler complaints - * Add 'USE_DL_PREFIX' to quickly allow co-existence with existing - memory allocation routines - * Set 'malloc_getpagesize' for WIN32 platforms (needs more work) - * Use 'assert' rather than 'ASSERT' in WIN32 code to conform to - usage of 'assert' in non-WIN32 code - * Improve WIN32 'sbrk()' emulation's 'findRegion()' routine to - avoid infinite loop - * Always call 'fREe()' rather than 'free()' - - V2.6.5 Wed Jun 17 15:57:31 1998 Doug Lea (dl at gee) - * Fixed ordering problem with boundary-stamping - - V2.6.3 Sun May 19 08:17:58 1996 Doug Lea (dl at gee) - * Added pvalloc, as recommended by H.J. Liu - * Added 64bit pointer support mainly from Wolfram Gloger - * Added anonymously donated WIN32 sbrk emulation - * Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen - * malloc_extend_top: fix mask error that caused wastage after - foreign sbrks - * Add linux mremap support code from HJ Liu - - V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee) - * Integrated most documentation with the code. - * Add support for mmap, with help from - Wolfram Gloger (Gloger@lrz.uni-muenchen.de). - * Use last_remainder in more cases. - * Pack bins using idea from colin@nyx10.cs.du.edu - * Use ordered bins instead of best-fit threshhold - * Eliminate block-local decls to simplify tracing and debugging. - * Support another case of realloc via move into top - * Fix error occuring when initial sbrk_base not word-aligned. - * Rely on page size for units instead of SBRK_UNIT to - avoid surprises about sbrk alignment conventions. - * Add mallinfo, mallopt. Thanks to Raymond Nijssen - (raymond@es.ele.tue.nl) for the suggestion. - * Add `pad' argument to malloc_trim and top_pad mallopt parameter. - * More precautions for cases where other routines call sbrk, - courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de). - * Added macros etc., allowing use in linux libc from - H.J. Lu (hjl@gnu.ai.mit.edu) - * Inverted this history list - - V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee) - * Re-tuned and fixed to behave more nicely with V2.6.0 changes. - * Removed all preallocation code since under current scheme - the work required to undo bad preallocations exceeds - the work saved in good cases for most test programs. - * No longer use return list or unconsolidated bins since - no scheme using them consistently outperforms those that don't - given above changes. - * Use best fit for very large chunks to prevent some worst-cases. - * Added some support for debugging - - V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee) - * Removed footers when chunks are in use. Thanks to - Paul Wilson (wilson@cs.texas.edu) for the suggestion. - - V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee) - * Added malloc_trim, with help from Wolfram Gloger - (wmglo@Dent.MED.Uni-Muenchen.DE). - - V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g) - - V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g) - * realloc: try to expand in both directions - * malloc: swap order of clean-bin strategy; - * realloc: only conditionally expand backwards - * Try not to scavenge used bins - * Use bin counts as a guide to preallocation - * Occasionally bin return list chunks in first scan - * Add a few optimizations from colin@nyx10.cs.du.edu - - V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g) - * faster bin computation & slightly different binning - * merged all consolidations to one part of malloc proper - (eliminating old malloc_find_space & malloc_clean_bin) - * Scan 2 returns chunks (not just 1) - * Propagate failure in realloc if malloc returns 0 - * Add stuff to allow compilation on non-ANSI compilers - from kpv@research.att.com - - V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu) - * removed potential for odd address access in prev_chunk - * removed dependency on getpagesize.h - * misc cosmetics and a bit more internal documentation - * anticosmetics: mangled names in macros to evade debugger strangeness - * tested on sparc, hp-700, dec-mips, rs6000 - with gcc & native cc (hp, dec only) allowing - Detlefs & Zorn comparison study (in SIGPLAN Notices.) - - Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu) - * Based loosely on libg++-1.2X malloc. (It retains some of the overall - structure of old version, but most details differ.) - -*/ |