#include <mach-o/loader.h>
#include <libkern/OSAtomic.h>
-#include "dyld_priv.h"
+#include <mach-o/dyld_priv.h>
#if __LP64__
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*);
#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
}
-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)
// 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 ) {
static void
tlv_free(void *storage)
{
- tlv_notify(dyld_tlv_state_deallocated, storage);
free(storage);
}
}
-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
//
}
}
-// 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);
}
// <rdar://problem/13741816>
// 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);
+ }
}
#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()
{
}
projects / apple / dyld.git / blobdiff