Index: compiler-rt/trunk/lib/builtins/CMakeLists.txt =================================================================== --- compiler-rt/trunk/lib/builtins/CMakeLists.txt +++ compiler-rt/trunk/lib/builtins/CMakeLists.txt @@ -139,6 +139,12 @@ umodsi3.c umodti3.c) +if(NOT WIN32) + set(GENERIC_SOURCES + ${GENERIC_SOURCES} + emutls.c) +endif() + if (HAVE_UNWIND_H) set(GENERIC_SOURCES ${GENERIC_SOURCES} Index: compiler-rt/trunk/lib/builtins/README.txt =================================================================== --- compiler-rt/trunk/lib/builtins/README.txt +++ compiler-rt/trunk/lib/builtins/README.txt @@ -220,7 +220,9 @@ // for use with some implementations of assert() in void __eprintf(const char* format, const char* assertion_expression, const char* line, const char* file); - + +// for systems with emulated thread local storage +void* __emutls_get_address(struct __emutls_control*); // Power PC specific functions Index: compiler-rt/trunk/lib/builtins/emutls.c =================================================================== --- compiler-rt/trunk/lib/builtins/emutls.c +++ compiler-rt/trunk/lib/builtins/emutls.c @@ -0,0 +1,181 @@ +/* ===---------- 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. + * + * ===----------------------------------------------------------------------=== + */ +#include +#include +#include +#include + +#include "int_util.h" + +/* 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 + +/* 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 { + size_t size; /* size of the object in bytes */ + size_t 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; + +static inline void* emutls_memalign_alloc(size_t align, size_t size) { + void *base; +#if EMUTLS_USE_POSIX_MEMALIGN + if (posix_memalign(&base, align, size) != 0) + abort(); +#else + #define EXTRA_ALIGN_PTR_BYTES (align - 1 + sizeof(void*)) + char* object; + if ((object = 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; +} + +static inline void emutls_memalign_free(void* base) { +#if EMUTLS_USE_POSIX_MEMALIGN + free(base); +#else + /* The mallocated address is in ((void**)base)[-1] */ + free(((void**)base)[-1]); +#endif +} + +/* 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. */ + typedef unsigned int gcc_word __attribute__((mode(word))); + typedef unsigned int gcc_pointer __attribute__((mode(pointer))); + COMPILE_TIME_ASSERT(sizeof(size_t) == sizeof(gcc_word)); + 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; + if (align < sizeof(void*)) + align = sizeof(void*); + /* Make sure that align is power of 2. */ + if ((align & (align - 1)) != 0) + abort(); + + void* base = emutls_memalign_alloc(align, size); + if (control->value) + memcpy(base, control->value, size); + else + memset(base, 0, size); + return base; +} + +static pthread_mutex_t emutls_mutex = PTHREAD_MUTEX_INITIALIZER; + +static size_t emutls_num_object = 0; /* number of allocated TLS objects */ + +typedef struct emutls_address_array { + uintptr_t size; /* number of elements in the 'data' array */ + void* data[]; +} emutls_address_array; + +static pthread_key_t emutls_pthread_key; + +static void emutls_key_destructor(void* ptr) { + emutls_address_array* array = (emutls_address_array*)ptr; + uintptr_t i; + for (i = 0; i < array->size; ++i) { + if (array->data[i]) + emutls_memalign_free(array->data[i]); + } + free(ptr); +} + +static void emutls_init(void) { + if (pthread_key_create(&emutls_pthread_key, emutls_key_destructor) != 0) + abort(); +} + +/* 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); + if (!index) { + static pthread_once_t once = PTHREAD_ONCE_INIT; + pthread_once(&once, emutls_init); + pthread_mutex_lock(&emutls_mutex); + index = control->object.index; + if (!index) { + index = ++emutls_num_object; + __atomic_store_n(&control->object.index, index, __ATOMIC_RELEASE); + } + pthread_mutex_unlock(&emutls_mutex); + } + return index; +} + +/* 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; + pthread_setspecific(emutls_pthread_key, (void*)array); +} + +/* 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 one extra slot + * to store the data array size. + * Round up the emutls_address_array size to multiple of 16. + */ + return ((index + 1 + 15) & ~((uintptr_t)15)) - 1; +} + +/* 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 = pthread_getspecific(emutls_pthread_key); + if (array == NULL) { + uintptr_t new_size = emutls_new_data_array_size(index); + array = calloc(new_size + 1, sizeof(void*)); + 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 = realloc(array, (new_size + 1) * sizeof(void*)); + 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 - 1] == NULL) + array->data[index - 1] = emutls_allocate_object(control); + return array->data[index - 1]; +} Index: compiler-rt/trunk/lib/builtins/int_util.h =================================================================== --- compiler-rt/trunk/lib/builtins/int_util.h +++ compiler-rt/trunk/lib/builtins/int_util.h @@ -26,4 +26,9 @@ void compilerrt_abort_impl(const char *file, int line, const char *function) __attribute__((noreturn)); +#define COMPILE_TIME_ASSERT(expr) COMPILE_TIME_ASSERT1(expr, __COUNTER__) +#define COMPILE_TIME_ASSERT1(expr, cnt) COMPILE_TIME_ASSERT2(expr, cnt) +#define COMPILE_TIME_ASSERT2(expr, cnt) \ + typedef char ct_assert_##cnt[(expr) ? 1 : -1] __attribute__((unused)) + #endif /* INT_UTIL_H */