diff options
Diffstat (limited to 'lib/builtins/emutls.c')
| -rw-r--r-- | lib/builtins/emutls.c | 494 |
1 files changed, 236 insertions, 258 deletions
diff --git a/lib/builtins/emutls.c b/lib/builtins/emutls.c index ef95a1c26..da58feb7b 100644 --- a/lib/builtins/emutls.c +++ b/lib/builtins/emutls.c @@ -1,37 +1,35 @@ -/* ===---------- emutls.c - Implements __emutls_get_address ---------------=== - * - * The LLVM Compiler Infrastructure - * - * This file is dual licensed under the MIT and the University of Illinois Open - * Source Licenses. See LICENSE.TXT for details. - * - * ===----------------------------------------------------------------------=== - */ +//===---------- emutls.c - Implements __emutls_get_address ---------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + #include <stdint.h> #include <stdlib.h> #include <string.h> #include "int_lib.h" -#include "int_util.h" #ifdef __BIONIC__ -/* There are 4 pthread key cleanup rounds on Bionic. Delay emutls deallocation - to round 2. We need to delay deallocation because: - - Android versions older than M lack __cxa_thread_atexit_impl, so apps - use a pthread key destructor to call C++ destructors. - - Apps might use __thread/thread_local variables in pthread destructors. - We can't wait until the final two rounds, because jemalloc needs two rounds - after the final malloc/free call to free its thread-specific data (see - https://reviews.llvm.org/D46978#1107507). */ +// There are 4 pthread key cleanup rounds on Bionic. Delay emutls deallocation +// to round 2. We need to delay deallocation because: +// - Android versions older than M lack __cxa_thread_atexit_impl, so apps +// use a pthread key destructor to call C++ destructors. +// - Apps might use __thread/thread_local variables in pthread destructors. +// We can't wait until the final two rounds, because jemalloc needs two rounds +// after the final malloc/free call to free its thread-specific data (see +// https://reviews.llvm.org/D46978#1107507). #define EMUTLS_SKIP_DESTRUCTOR_ROUNDS 1 #else #define EMUTLS_SKIP_DESTRUCTOR_ROUNDS 0 #endif typedef struct emutls_address_array { - uintptr_t skip_destructor_rounds; - uintptr_t size; /* number of elements in the 'data' array */ - void* data[]; + uintptr_t skip_destructor_rounds; + uintptr_t size; // number of elements in the 'data' array + void *data[]; } emutls_address_array; static void emutls_shutdown(emutls_address_array *array); @@ -47,359 +45,339 @@ static bool emutls_key_created = false; typedef unsigned int gcc_word __attribute__((mode(word))); typedef unsigned int gcc_pointer __attribute__((mode(pointer))); -/* Default is not to use posix_memalign, so systems like Android - * can use thread local data without heavier POSIX memory allocators. - */ +// Default is not to use posix_memalign, so systems like Android +// can use thread local data without heavier POSIX memory allocators. #ifndef EMUTLS_USE_POSIX_MEMALIGN #define EMUTLS_USE_POSIX_MEMALIGN 0 #endif static __inline void *emutls_memalign_alloc(size_t align, size_t size) { - void *base; + void *base; #if EMUTLS_USE_POSIX_MEMALIGN - if (posix_memalign(&base, align, size) != 0) - abort(); + if (posix_memalign(&base, align, size) != 0) + abort(); #else - #define EXTRA_ALIGN_PTR_BYTES (align - 1 + sizeof(void*)) - char* object; - if ((object = (char*)malloc(EXTRA_ALIGN_PTR_BYTES + size)) == NULL) - abort(); - base = (void*)(((uintptr_t)(object + EXTRA_ALIGN_PTR_BYTES)) - & ~(uintptr_t)(align - 1)); - - ((void**)base)[-1] = object; +#define EXTRA_ALIGN_PTR_BYTES (align - 1 + sizeof(void *)) + char *object; + if ((object = (char *)malloc(EXTRA_ALIGN_PTR_BYTES + size)) == NULL) + abort(); + base = (void *)(((uintptr_t)(object + EXTRA_ALIGN_PTR_BYTES)) & + ~(uintptr_t)(align - 1)); + + ((void **)base)[-1] = object; #endif - return base; + return base; } static __inline void emutls_memalign_free(void *base) { #if EMUTLS_USE_POSIX_MEMALIGN - free(base); + free(base); #else - /* The mallocated address is in ((void**)base)[-1] */ - free(((void**)base)[-1]); + // The mallocated address is in ((void**)base)[-1] + free(((void **)base)[-1]); #endif } static __inline void emutls_setspecific(emutls_address_array *value) { - pthread_setspecific(emutls_pthread_key, (void*) value); + pthread_setspecific(emutls_pthread_key, (void *)value); } -static __inline emutls_address_array* emutls_getspecific() { - return (emutls_address_array*) pthread_getspecific(emutls_pthread_key); +static __inline emutls_address_array *emutls_getspecific() { + return (emutls_address_array *)pthread_getspecific(emutls_pthread_key); } -static void emutls_key_destructor(void* ptr) { - emutls_address_array *array = (emutls_address_array*)ptr; - if (array->skip_destructor_rounds > 0) { - /* emutls is deallocated using a pthread key destructor. These - * destructors are called in several rounds to accommodate destructor - * functions that (re)initialize key values with pthread_setspecific. - * Delay the emutls deallocation to accommodate other end-of-thread - * cleanup tasks like calling thread_local destructors (e.g. the - * __cxa_thread_atexit fallback in libc++abi). - */ - array->skip_destructor_rounds--; - emutls_setspecific(array); - } else { - emutls_shutdown(array); - free(ptr); - } +static void emutls_key_destructor(void *ptr) { + emutls_address_array *array = (emutls_address_array *)ptr; + if (array->skip_destructor_rounds > 0) { + // emutls is deallocated using a pthread key destructor. These + // destructors are called in several rounds to accommodate destructor + // functions that (re)initialize key values with pthread_setspecific. + // Delay the emutls deallocation to accommodate other end-of-thread + // cleanup tasks like calling thread_local destructors (e.g. the + // __cxa_thread_atexit fallback in libc++abi). + array->skip_destructor_rounds--; + emutls_setspecific(array); + } else { + emutls_shutdown(array); + free(ptr); + } } static __inline void emutls_init(void) { - if (pthread_key_create(&emutls_pthread_key, emutls_key_destructor) != 0) - abort(); - emutls_key_created = true; + if (pthread_key_create(&emutls_pthread_key, emutls_key_destructor) != 0) + abort(); + emutls_key_created = true; } static __inline void emutls_init_once(void) { - static pthread_once_t once = PTHREAD_ONCE_INIT; - pthread_once(&once, emutls_init); + static pthread_once_t once = PTHREAD_ONCE_INIT; + pthread_once(&once, emutls_init); } -static __inline void emutls_lock() { - pthread_mutex_lock(&emutls_mutex); -} +static __inline void emutls_lock() { pthread_mutex_lock(&emutls_mutex); } -static __inline void emutls_unlock() { - pthread_mutex_unlock(&emutls_mutex); -} +static __inline void emutls_unlock() { pthread_mutex_unlock(&emutls_mutex); } -#else /* _WIN32 */ +#else // _WIN32 -#include <windows.h> +#include <assert.h> #include <malloc.h> #include <stdio.h> -#include <assert.h> +#include <windows.h> static LPCRITICAL_SECTION emutls_mutex; static DWORD emutls_tls_index = TLS_OUT_OF_INDEXES; typedef uintptr_t gcc_word; -typedef void * gcc_pointer; +typedef void *gcc_pointer; static void win_error(DWORD last_err, const char *hint) { - char *buffer = NULL; - if (FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | - FORMAT_MESSAGE_FROM_SYSTEM | - FORMAT_MESSAGE_MAX_WIDTH_MASK, - NULL, last_err, 0, (LPSTR)&buffer, 1, NULL)) { - fprintf(stderr, "Windows error: %s\n", buffer); - } else { - fprintf(stderr, "Unkown Windows error: %s\n", hint); - } - LocalFree(buffer); + char *buffer = NULL; + if (FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | + FORMAT_MESSAGE_FROM_SYSTEM | + FORMAT_MESSAGE_MAX_WIDTH_MASK, + NULL, last_err, 0, (LPSTR)&buffer, 1, NULL)) { + fprintf(stderr, "Windows error: %s\n", buffer); + } else { + fprintf(stderr, "Unkown Windows error: %s\n", hint); + } + LocalFree(buffer); } static __inline void win_abort(DWORD last_err, const char *hint) { - win_error(last_err, hint); - abort(); + win_error(last_err, hint); + abort(); } static __inline void *emutls_memalign_alloc(size_t align, size_t size) { - void *base = _aligned_malloc(size, align); - if (!base) - win_abort(GetLastError(), "_aligned_malloc"); - return base; + void *base = _aligned_malloc(size, align); + if (!base) + win_abort(GetLastError(), "_aligned_malloc"); + return base; } -static __inline void emutls_memalign_free(void *base) { - _aligned_free(base); -} +static __inline void emutls_memalign_free(void *base) { _aligned_free(base); } static void emutls_exit(void) { - if (emutls_mutex) { - DeleteCriticalSection(emutls_mutex); - _aligned_free(emutls_mutex); - emutls_mutex = NULL; - } - if (emutls_tls_index != TLS_OUT_OF_INDEXES) { - emutls_shutdown((emutls_address_array*)TlsGetValue(emutls_tls_index)); - TlsFree(emutls_tls_index); - emutls_tls_index = TLS_OUT_OF_INDEXES; - } + if (emutls_mutex) { + DeleteCriticalSection(emutls_mutex); + _aligned_free(emutls_mutex); + emutls_mutex = NULL; + } + if (emutls_tls_index != TLS_OUT_OF_INDEXES) { + emutls_shutdown((emutls_address_array *)TlsGetValue(emutls_tls_index)); + TlsFree(emutls_tls_index); + emutls_tls_index = TLS_OUT_OF_INDEXES; + } } -#pragma warning (push) -#pragma warning (disable : 4100) +#pragma warning(push) +#pragma warning(disable : 4100) static BOOL CALLBACK emutls_init(PINIT_ONCE p0, PVOID p1, PVOID *p2) { - emutls_mutex = (LPCRITICAL_SECTION)_aligned_malloc(sizeof(CRITICAL_SECTION), 16); - if (!emutls_mutex) { - win_error(GetLastError(), "_aligned_malloc"); - return FALSE; - } - InitializeCriticalSection(emutls_mutex); - - emutls_tls_index = TlsAlloc(); - if (emutls_tls_index == TLS_OUT_OF_INDEXES) { - emutls_exit(); - win_error(GetLastError(), "TlsAlloc"); - return FALSE; - } - atexit(&emutls_exit); - return TRUE; + emutls_mutex = + (LPCRITICAL_SECTION)_aligned_malloc(sizeof(CRITICAL_SECTION), 16); + if (!emutls_mutex) { + win_error(GetLastError(), "_aligned_malloc"); + return FALSE; + } + InitializeCriticalSection(emutls_mutex); + + emutls_tls_index = TlsAlloc(); + if (emutls_tls_index == TLS_OUT_OF_INDEXES) { + emutls_exit(); + win_error(GetLastError(), "TlsAlloc"); + return FALSE; + } + atexit(&emutls_exit); + return TRUE; } static __inline void emutls_init_once(void) { - static INIT_ONCE once; - InitOnceExecuteOnce(&once, emutls_init, NULL, NULL); + static INIT_ONCE once; + InitOnceExecuteOnce(&once, emutls_init, NULL, NULL); } -static __inline void emutls_lock() { - EnterCriticalSection(emutls_mutex); -} +static __inline void emutls_lock() { EnterCriticalSection(emutls_mutex); } -static __inline void emutls_unlock() { - LeaveCriticalSection(emutls_mutex); -} +static __inline void emutls_unlock() { LeaveCriticalSection(emutls_mutex); } static __inline void emutls_setspecific(emutls_address_array *value) { - if (TlsSetValue(emutls_tls_index, (LPVOID) value) == 0) - win_abort(GetLastError(), "TlsSetValue"); + if (TlsSetValue(emutls_tls_index, (LPVOID)value) == 0) + win_abort(GetLastError(), "TlsSetValue"); } -static __inline emutls_address_array* emutls_getspecific() { - LPVOID value = TlsGetValue(emutls_tls_index); - if (value == NULL) { - const DWORD err = GetLastError(); - if (err != ERROR_SUCCESS) - win_abort(err, "TlsGetValue"); - } - return (emutls_address_array*) value; +static __inline emutls_address_array *emutls_getspecific() { + LPVOID value = TlsGetValue(emutls_tls_index); + if (value == NULL) { + const DWORD err = GetLastError(); + if (err != ERROR_SUCCESS) + win_abort(err, "TlsGetValue"); + } + return (emutls_address_array *)value; } -/* Provide atomic load/store functions for emutls_get_index if built with MSVC. - */ +// Provide atomic load/store functions for emutls_get_index if built with MSVC. #if !defined(__ATOMIC_RELEASE) #include <intrin.h> enum { __ATOMIC_ACQUIRE = 2, __ATOMIC_RELEASE = 3 }; static __inline uintptr_t __atomic_load_n(void *ptr, unsigned type) { - assert(type == __ATOMIC_ACQUIRE); - // These return the previous value - but since we do an OR with 0, - // it's equivalent to a plain load. + assert(type == __ATOMIC_ACQUIRE); + // These return the previous value - but since we do an OR with 0, + // it's equivalent to a plain load. #ifdef _WIN64 - return InterlockedOr64(ptr, 0); + return InterlockedOr64(ptr, 0); #else - return InterlockedOr(ptr, 0); + return InterlockedOr(ptr, 0); #endif } static __inline void __atomic_store_n(void *ptr, uintptr_t val, unsigned type) { - assert(type == __ATOMIC_RELEASE); - InterlockedExchangePointer((void *volatile *)ptr, (void *)val); + assert(type == __ATOMIC_RELEASE); + InterlockedExchangePointer((void *volatile *)ptr, (void *)val); } -#endif /* __ATOMIC_RELEASE */ +#endif // __ATOMIC_RELEASE -#pragma warning (pop) +#pragma warning(pop) -#endif /* _WIN32 */ +#endif // _WIN32 -static size_t emutls_num_object = 0; /* number of allocated TLS objects */ +static size_t emutls_num_object = 0; // number of allocated TLS objects -/* Free the allocated TLS data - */ +// Free the allocated TLS data static void emutls_shutdown(emutls_address_array *array) { - if (array) { - uintptr_t i; - for (i = 0; i < array->size; ++i) { - if (array->data[i]) - emutls_memalign_free(array->data[i]); - } + if (array) { + uintptr_t i; + for (i = 0; i < array->size; ++i) { + if (array->data[i]) + emutls_memalign_free(array->data[i]); } + } } -/* For every TLS variable xyz, - * there is one __emutls_control variable named __emutls_v.xyz. - * If xyz has non-zero initial value, __emutls_v.xyz's "value" - * will point to __emutls_t.xyz, which has the initial value. - */ +// For every TLS variable xyz, +// there is one __emutls_control variable named __emutls_v.xyz. +// If xyz has non-zero initial value, __emutls_v.xyz's "value" +// will point to __emutls_t.xyz, which has the initial value. typedef struct __emutls_control { - /* Must use gcc_word here, instead of size_t, to match GCC. When - gcc_word is larger than size_t, the upper extra bits are all - zeros. We can use variables of size_t to operate on size and - align. */ - gcc_word size; /* size of the object in bytes */ - gcc_word align; /* alignment of the object in bytes */ - union { - uintptr_t index; /* data[index-1] is the object address */ - void* address; /* object address, when in single thread env */ - } object; - void* value; /* null or non-zero initial value for the object */ + // Must use gcc_word here, instead of size_t, to match GCC. When + // gcc_word is larger than size_t, the upper extra bits are all + // zeros. We can use variables of size_t to operate on size and + // align. + gcc_word size; // size of the object in bytes + gcc_word align; // alignment of the object in bytes + union { + uintptr_t index; // data[index-1] is the object address + void *address; // object address, when in single thread env + } object; + void *value; // null or non-zero initial value for the object } __emutls_control; -/* Emulated TLS objects are always allocated at run-time. */ +// Emulated TLS objects are always allocated at run-time. static __inline void *emutls_allocate_object(__emutls_control *control) { - /* Use standard C types, check with gcc's emutls.o. */ - COMPILE_TIME_ASSERT(sizeof(uintptr_t) == sizeof(gcc_pointer)); - COMPILE_TIME_ASSERT(sizeof(uintptr_t) == sizeof(void*)); - - size_t size = control->size; - size_t align = control->align; - void* base; - if (align < sizeof(void*)) - align = sizeof(void*); - /* Make sure that align is power of 2. */ - if ((align & (align - 1)) != 0) - abort(); - - base = emutls_memalign_alloc(align, size); - if (control->value) - memcpy(base, control->value, size); - else - memset(base, 0, size); - return base; -} + // Use standard C types, check with gcc's emutls.o. + COMPILE_TIME_ASSERT(sizeof(uintptr_t) == sizeof(gcc_pointer)); + COMPILE_TIME_ASSERT(sizeof(uintptr_t) == sizeof(void *)); + + size_t size = control->size; + size_t align = control->align; + void *base; + if (align < sizeof(void *)) + align = sizeof(void *); + // Make sure that align is power of 2. + if ((align & (align - 1)) != 0) + abort(); + base = emutls_memalign_alloc(align, size); + if (control->value) + memcpy(base, control->value, size); + else + memset(base, 0, size); + return base; +} -/* Returns control->object.index; set index if not allocated yet. */ +// Returns control->object.index; set index if not allocated yet. static __inline uintptr_t emutls_get_index(__emutls_control *control) { - uintptr_t index = __atomic_load_n(&control->object.index, __ATOMIC_ACQUIRE); + uintptr_t index = __atomic_load_n(&control->object.index, __ATOMIC_ACQUIRE); + if (!index) { + emutls_init_once(); + emutls_lock(); + index = control->object.index; if (!index) { - emutls_init_once(); - emutls_lock(); - index = control->object.index; - if (!index) { - index = ++emutls_num_object; - __atomic_store_n(&control->object.index, index, __ATOMIC_RELEASE); - } - emutls_unlock(); + index = ++emutls_num_object; + __atomic_store_n(&control->object.index, index, __ATOMIC_RELEASE); } - return index; + emutls_unlock(); + } + return index; } -/* Updates newly allocated thread local emutls_address_array. */ +// Updates newly allocated thread local emutls_address_array. static __inline void emutls_check_array_set_size(emutls_address_array *array, uintptr_t size) { - if (array == NULL) - abort(); - array->size = size; - emutls_setspecific(array); + if (array == NULL) + abort(); + array->size = size; + emutls_setspecific(array); } -/* Returns the new 'data' array size, number of elements, - * which must be no smaller than the given index. - */ +// Returns the new 'data' array size, number of elements, +// which must be no smaller than the given index. static __inline uintptr_t emutls_new_data_array_size(uintptr_t index) { - /* Need to allocate emutls_address_array with extra slots - * to store the header. - * Round up the emutls_address_array size to multiple of 16. - */ - uintptr_t header_words = sizeof(emutls_address_array) / sizeof(void *); - return ((index + header_words + 15) & ~((uintptr_t)15)) - header_words; + // Need to allocate emutls_address_array with extra slots + // to store the header. + // Round up the emutls_address_array size to multiple of 16. + uintptr_t header_words = sizeof(emutls_address_array) / sizeof(void *); + return ((index + header_words + 15) & ~((uintptr_t)15)) - header_words; } -/* Returns the size in bytes required for an emutls_address_array with - * N number of elements for data field. - */ +// Returns the size in bytes required for an emutls_address_array with +// N number of elements for data field. static __inline uintptr_t emutls_asize(uintptr_t N) { - return N * sizeof(void *) + sizeof(emutls_address_array); + return N * sizeof(void *) + sizeof(emutls_address_array); } -/* Returns the thread local emutls_address_array. - * Extends its size if necessary to hold address at index. - */ +// Returns the thread local emutls_address_array. +// Extends its size if necessary to hold address at index. static __inline emutls_address_array * emutls_get_address_array(uintptr_t index) { - emutls_address_array* array = emutls_getspecific(); - if (array == NULL) { - uintptr_t new_size = emutls_new_data_array_size(index); - array = (emutls_address_array*) malloc(emutls_asize(new_size)); - if (array) { - memset(array->data, 0, new_size * sizeof(void*)); - array->skip_destructor_rounds = EMUTLS_SKIP_DESTRUCTOR_ROUNDS; - } - emutls_check_array_set_size(array, new_size); - } else if (index > array->size) { - uintptr_t orig_size = array->size; - uintptr_t new_size = emutls_new_data_array_size(index); - array = (emutls_address_array*) realloc(array, emutls_asize(new_size)); - if (array) - memset(array->data + orig_size, 0, - (new_size - orig_size) * sizeof(void*)); - emutls_check_array_set_size(array, new_size); + emutls_address_array *array = emutls_getspecific(); + if (array == NULL) { + uintptr_t new_size = emutls_new_data_array_size(index); + array = (emutls_address_array *)malloc(emutls_asize(new_size)); + if (array) { + memset(array->data, 0, new_size * sizeof(void *)); + array->skip_destructor_rounds = EMUTLS_SKIP_DESTRUCTOR_ROUNDS; } - return array; + emutls_check_array_set_size(array, new_size); + } else if (index > array->size) { + uintptr_t orig_size = array->size; + uintptr_t new_size = emutls_new_data_array_size(index); + array = (emutls_address_array *)realloc(array, emutls_asize(new_size)); + if (array) + memset(array->data + orig_size, 0, + (new_size - orig_size) * sizeof(void *)); + emutls_check_array_set_size(array, new_size); + } + return array; } -void* __emutls_get_address(__emutls_control* control) { - uintptr_t index = emutls_get_index(control); - emutls_address_array* array = emutls_get_address_array(index--); - if (array->data[index] == NULL) - array->data[index] = emutls_allocate_object(control); - return array->data[index]; +void *__emutls_get_address(__emutls_control *control) { + uintptr_t index = emutls_get_index(control); + emutls_address_array *array = emutls_get_address_array(index--); + if (array->data[index] == NULL) + array->data[index] = emutls_allocate_object(control); + return array->data[index]; } #ifdef __BIONIC__ -/* Called by Bionic on dlclose to delete the emutls pthread key. */ -__attribute__((visibility("hidden"))) -void __emutls_unregister_key(void) { - if (emutls_key_created) { - pthread_key_delete(emutls_pthread_key); - emutls_key_created = false; - } +// Called by Bionic on dlclose to delete the emutls pthread key. +__attribute__((visibility("hidden"))) void __emutls_unregister_key(void) { + if (emutls_key_created) { + pthread_key_delete(emutls_pthread_key); + emutls_key_created = false; + } } #endif |