X-Git-Url: https://git.saurik.com/apple/dyld.git/blobdiff_plain/10b92d3b56e938a5c1f5e708ddd1c5d0c2c807d1..refs/heads/master:/src/threadLocalVariables.c diff --git a/src/threadLocalVariables.c b/src/threadLocalVariables.c index a0b3661..bb3c5ff 100644 --- a/src/threadLocalVariables.c +++ b/src/threadLocalVariables.c @@ -34,7 +34,7 @@ #include #include -#include "dyld_priv.h" +#include #if __LP64__ @@ -49,30 +49,6 @@ typedef struct section macho_section; #endif -#ifndef S_THREAD_LOCAL_REGULAR -#define S_THREAD_LOCAL_REGULAR 0x11 -#endif - -#ifndef S_THREAD_LOCAL_ZEROFILL -#define S_THREAD_LOCAL_ZEROFILL 0x12 -#endif - -#ifndef S_THREAD_LOCAL_VARIABLES -#define S_THREAD_LOCAL_VARIABLES 0x13 -#endif - -#ifndef S_THREAD_LOCAL_VARIABLE_POINTERS -#define S_THREAD_LOCAL_VARIABLE_POINTERS 0x14 -#endif - -#ifndef S_THREAD_LOCAL_INIT_FUNCTION_POINTERS -#define S_THREAD_LOCAL_INIT_FUNCTION_POINTERS 0x15 -#endif - -#ifndef MH_HAS_TLV_DESCRIPTORS - #define MH_HAS_TLV_DESCRIPTORS 0x800000 -#endif - typedef void (*TermFunc)(void*); @@ -80,14 +56,14 @@ typedef void (*TermFunc)(void*); #if __has_feature(tls) || __arm64__ || __arm__ -typedef struct TLVHandler { - struct TLVHandler *next; - dyld_tlv_state_change_handler handler; - enum dyld_tlv_states state; -} TLVHandler; - -// lock-free prepend-only linked list -static TLVHandler * volatile tlv_handlers = NULL; +// +// Info about thread-local variable storage. +// +typedef struct { + size_t info_size; // sizeof(dyld_tlv_info) + void * tlv_addr; // Base address of TLV storage + size_t tlv_size; // Byte size of TLV storage +} dyld_tlv_info; struct TLVDescriptor @@ -148,23 +124,6 @@ static const struct mach_header* tlv_get_image_for_key(pthread_key_t key) } -static void -tlv_notify(enum dyld_tlv_states state, void *buffer) -{ - if (!tlv_handlers) return; - - // Always use malloc_size() to ensure allocated and deallocated states - // send the same size. tlv_free() doesn't have anything else recorded. - dyld_tlv_info info = { sizeof(info), buffer, malloc_size(buffer) }; - - for (TLVHandler *h = tlv_handlers; h != NULL; h = h->next) { - if (h->state == state && h->handler) { - h->handler(h->state, &info); - } - } -} - - // called lazily when TLV is first accessed __attribute__((visibility("hidden"))) void* tlv_allocate_and_initialize_for_key(pthread_key_t key) @@ -224,9 +183,6 @@ void* tlv_allocate_and_initialize_for_key(pthread_key_t key) // set this thread's value for key to be the new buffer. pthread_setspecific(key, buffer); - - // send tlv state notifications - tlv_notify(dyld_tlv_state_allocated, buffer); // second pass, run initializers if ( hasInitializers ) { @@ -259,7 +215,6 @@ void* tlv_allocate_and_initialize_for_key(pthread_key_t key) static void tlv_free(void *storage) { - tlv_notify(dyld_tlv_state_deallocated, storage); free(storage); } @@ -318,39 +273,6 @@ static void tlv_load_notification(const struct mach_header* mh, intptr_t slide) } -void dyld_register_tlv_state_change_handler(enum dyld_tlv_states state, dyld_tlv_state_change_handler handler) -{ - TLVHandler *h = malloc(sizeof(TLVHandler)); - h->state = state; - h->handler = Block_copy(handler); - - TLVHandler *old; - do { - old = tlv_handlers; - h->next = old; - } while (! OSAtomicCompareAndSwapPtrBarrier(old, h, (void * volatile *)&tlv_handlers)); -} - - -void dyld_enumerate_tlv_storage(dyld_tlv_state_change_handler handler) -{ - pthread_mutex_lock(&tlv_live_image_lock); - unsigned int count = tlv_live_image_used_count; - void *list[count]; - for (unsigned int i = 0; i < count; ++i) { - list[i] = pthread_getspecific(tlv_live_images[i].key); - } - pthread_mutex_unlock(&tlv_live_image_lock); - - for (unsigned int i = 0; i < count; ++i) { - if (list[i]) { - dyld_tlv_info info = { sizeof(info), list[i], malloc_size(list[i]) }; - handler(dyld_tlv_state_allocated, &info); - } - } -} - - // // thread_local terminators // @@ -417,29 +339,52 @@ void _tlv_atexit(TermFunc func, void* objAddr) } } -// called by pthreads when the current thread is going away and -// _tlv_atexit() has been called on the thread. -static void tlv_finalize(void* storage) -{ - struct TLVTerminatorList* list = (struct TLVTerminatorList*)storage; +static void tlv_finalize_list(struct TLVTerminatorList* list) { // destroy in reverse order of construction for(uint32_t i=list->useCount; i > 0 ; --i) { struct TLVTerminatorListEntry* entry = &list->entries[i-1]; if ( entry->termFunc != NULL ) { (*entry->termFunc)(entry->objAddr); } + + // If a new tlv was added via tlv_atexit, then we need to immediately + // destroy it + struct TLVTerminatorList* newlist = (struct TLVTerminatorList*)pthread_getspecific(tlv_terminators_key); + if ( newlist != NULL ) { + // Set the list to NULL so that if yet another tlv is registered, we put it in a new list + pthread_setspecific(tlv_terminators_key, NULL); + tlv_finalize_list(newlist); + } } - free(storage); + free(list); +} + +// called by pthreads when the current thread is going away and +// _tlv_atexit() has been called on the thread. +static void tlv_finalize(void* storage) +{ + // Note, on entry to this function, _tlv_exit set the list to NULL. libpthread + // also set it to NULL before calling us. If new thread locals are added to our + // tlv_terminators_key, then they will be on a new list, but the list we have here + // is one we own and need to destroy it + tlv_finalize_list((struct TLVTerminatorList*)storage); } // // called by exit() before it calls cxa_finalize() so that thread_local // objects are destroyed before global objects. +// Note this is only called on macOS, and by libc. +// iOS only destroys tlv's when each thread is destroyed and libpthread calls +// tlv_finalize as that is the pointer we provided when we created the key void _tlv_exit() { - void* termFuncs = pthread_getspecific(tlv_terminators_key); - if ( termFuncs != NULL ) - tlv_finalize(termFuncs); + void* termFuncs = pthread_getspecific(tlv_terminators_key); + if ( termFuncs != NULL ) { + // Clear the value so that calls to tlv_atexit during tlv_finalize + // will go on to a new list to destroy. + pthread_setspecific(tlv_terminators_key, NULL); + tlv_finalize(termFuncs); + } } @@ -467,16 +412,6 @@ void _tlv_bootstrap() #else - - -void dyld_register_tlv_state_change_handler(enum dyld_tlv_states state, dyld_tlv_state_change_handler handler) -{ -} - -void dyld_enumerate_tlv_storage(dyld_tlv_state_change_handler handler) -{ -} - void _tlv_exit() { }