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Diffstat (limited to 'mmalloc/mmap-sup.c')
| -rw-r--r-- | mmalloc/mmap-sup.c | 210 |
1 files changed, 0 insertions, 210 deletions
diff --git a/mmalloc/mmap-sup.c b/mmalloc/mmap-sup.c deleted file mode 100644 index 56146e29522..00000000000 --- a/mmalloc/mmap-sup.c +++ /dev/null @@ -1,210 +0,0 @@ -/* Support for an sbrk-like function that uses mmap. - Copyright 1992, 2000 Free Software Foundation, Inc. - - Contributed by Fred Fish at Cygnus Support. fnf@cygnus.com - -This file is part of the GNU C Library. - -The GNU C Library is free software; you can redistribute it and/or -modify it under the terms of the GNU Library General Public License as -published by the Free Software Foundation; either version 2 of the -License, or (at your option) any later version. - -The GNU C Library is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -Library General Public License for more details. - -You should have received a copy of the GNU Library General Public -License along with the GNU C Library; see the file COPYING.LIB. If -not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, -Boston, MA 02111-1307, USA. */ - -#if defined(HAVE_MMAP) - -#ifdef HAVE_UNISTD_H -#include <unistd.h> /* Prototypes for lseek */ -#endif -#include <stdio.h> -#include <fcntl.h> -#include <sys/mman.h> - -#ifndef SEEK_SET -#define SEEK_SET 0 -#endif - -#include "mmprivate.h" - -/* Cache the pagesize for the current host machine. Note that if the host - does not readily provide a getpagesize() function, we need to emulate it - elsewhere, not clutter up this file with lots of kluges to try to figure - it out. */ - -static size_t pagesize; -#if NEED_DECLARATION_GETPAGESIZE -extern int getpagesize PARAMS ((void)); -#endif - -#define PAGE_ALIGN(addr) (caddr_t) (((long)(addr) + pagesize - 1) & \ - ~(pagesize - 1)) - -/* Get core for the memory region specified by MDP, using SIZE as the - amount to either add to or subtract from the existing region. Works - like sbrk(), but using mmap(). */ - -PTR -__mmalloc_mmap_morecore (mdp, size) - struct mdesc *mdp; - int size; -{ - PTR result = NULL; - off_t foffset; /* File offset at which new mapping will start */ - size_t mapbytes; /* Number of bytes to map */ - caddr_t moveto; /* Address where we wish to move "break value" to */ - caddr_t mapto; /* Address we actually mapped to */ - char buf = 0; /* Single byte to write to extend mapped file */ - - if (pagesize == 0) - { - pagesize = getpagesize (); - } - if (size == 0) - { - /* Just return the current "break" value. */ - result = mdp -> breakval; - } - else if (size < 0) - { - /* We are deallocating memory. If the amount requested would cause - us to try to deallocate back past the base of the mmap'd region - then do nothing, and return NULL. Otherwise, deallocate the - memory and return the old break value. */ - if (mdp -> breakval + size >= mdp -> base) - { - result = (PTR) mdp -> breakval; - mdp -> breakval += size; - moveto = PAGE_ALIGN (mdp -> breakval); - munmap (moveto, (size_t) (mdp -> top - moveto)); - mdp -> top = moveto; - } - } - else - { - /* We are allocating memory. Make sure we have an open file - descriptor and then go on to get the memory. */ - if (mdp -> fd < 0) - { - result = NULL; - } - else if (mdp -> breakval + size > mdp -> top) - { - /* The request would move us past the end of the currently - mapped memory, so map in enough more memory to satisfy - the request. This means we also have to grow the mapped-to - file by an appropriate amount, since mmap cannot be used - to extend a file. */ - moveto = PAGE_ALIGN (mdp -> breakval + size); - mapbytes = moveto - mdp -> top; - foffset = mdp -> top - mdp -> base; - /* FIXME: Test results of lseek() and write() */ - lseek (mdp -> fd, foffset + mapbytes - 1, SEEK_SET); - write (mdp -> fd, &buf, 1); - if (mdp -> base == 0) - { - /* Let mmap pick the map start address */ - mapto = mmap (0, mapbytes, PROT_READ | PROT_WRITE, - MAP_SHARED, mdp -> fd, foffset); - if (mapto != (caddr_t) -1) - { - mdp -> base = mdp -> breakval = mapto; - mdp -> top = mdp -> base + mapbytes; - result = (PTR) mdp -> breakval; - mdp -> breakval += size; - } - } - else - { - mapto = mmap (mdp -> top, mapbytes, PROT_READ | PROT_WRITE, - MAP_SHARED | MAP_FIXED, mdp -> fd, foffset); - if (mapto == mdp -> top) - { - mdp -> top = moveto; - result = (PTR) mdp -> breakval; - mdp -> breakval += size; - } - } - } - else - { - result = (PTR) mdp -> breakval; - mdp -> breakval += size; - } - } - return (result); -} - -PTR -__mmalloc_remap_core (mdp) - struct mdesc *mdp; -{ - caddr_t base; - - /* FIXME: Quick hack, needs error checking and other attention. */ - - base = mmap (mdp -> base, mdp -> top - mdp -> base, - PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, - mdp -> fd, 0); - return ((PTR) base); -} - -PTR -mmalloc_findbase (size) - int size; -{ - int fd; - int flags; - caddr_t base = NULL; - -#ifdef MAP_ANONYMOUS - flags = MAP_SHARED | MAP_ANONYMOUS; - fd = -1; -#else -#ifdef MAP_FILE - flags = MAP_SHARED | MAP_FILE; -#else - flags = MAP_SHARED; -#endif - fd = open ("/dev/zero", O_RDWR); - if (fd != -1) - { - return ((PTR) NULL); - } -#endif - base = mmap (0, size, PROT_READ | PROT_WRITE, flags, fd, 0); - if (base != (caddr_t) -1) - { - munmap (base, (size_t) size); - } - if (fd != -1) - { - close (fd); - } - if (base == 0) - { - /* Don't allow mapping at address zero. We use that value - to signal an error return, and besides, it is useful to - catch NULL pointers if it is unmapped. Instead start - at the next page boundary. */ - base = (caddr_t) getpagesize (); - } - else if (base == (caddr_t) -1) - { - base = NULL; - } - return ((PTR) base); -} - -#else /* defined(HAVE_MMAP) */ -/* Prevent "empty translation unit" warnings from the idiots at X3J11. */ -static char ansi_c_idiots = 69; -#endif /* defined(HAVE_MMAP) */ |