dyld-635.2.tar.gz

[apple/dyld.git] / src / threadLocalVariables.c

diff --git a/src/threadLocalVariables.c b/src/threadLocalVariables.c
index 2586455ed2f6462b725b73b1a7b5a3011af114f8..a0b36615ab08c37f9987566bcdd91107bec0ab9a 100644 (file)
--- a/src/threadLocalVariables.c
+++ b/src/threadLocalVariables.c
@@ -73,7 +73,12 @@
        #define MH_HAS_TLV_DESCRIPTORS 0x800000
 #endif
 
-#if __i386__ || __x86_64__
+
+typedef void (*TermFunc)(void*);
+
+
+
+#if __has_feature(tls) || __arm64__ || __arm__
 
 typedef struct TLVHandler {
        struct TLVHandler *next;
@@ -165,9 +170,12 @@ __attribute__((visibility("hidden")))
 void* tlv_allocate_and_initialize_for_key(pthread_key_t key)
 {
        const struct mach_header* mh = tlv_get_image_for_key(key);
+       if ( mh == NULL )
+               return NULL;    // if data structures are screwed up, don't crash
+       
        // first pass, find size and template
        uint8_t*                start = NULL;
-       unsigned long   size;
+       unsigned long   size = 0;
        intptr_t                slide = 0;
        bool                    slideComputed = false;
        bool                    hasInitializers = false;
@@ -206,6 +214,9 @@ void* tlv_allocate_and_initialize_for_key(pthread_key_t key)
                }
                cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
        }
+    // no thread local storage in image: should never happen
+    if ( size == 0 )
+        return NULL;
        
        // allocate buffer and fill with template
        void* buffer = malloc(size);
@@ -229,9 +240,9 @@ void* tlv_allocate_and_initialize_for_key(pthread_key_t key)
                                        if ( (sect->flags & SECTION_TYPE) == S_THREAD_LOCAL_INIT_FUNCTION_POINTERS ) {
                                                typedef void (*InitFunc)(void);
                                                InitFunc* funcs = (InitFunc*)(sect->addr + slide);
-                                               const uint32_t count = sect->size / sizeof(uintptr_t);
-                                               for (uint32_t i=count; i > 0; --i) {
-                                                       InitFunc func = funcs[i-1];
+                                               const size_t count = sect->size / sizeof(uintptr_t);
+                                               for (size_t j=count; j > 0; --j) {
+                                                       InitFunc func = funcs[j-1];
                                                        func();
                                                }
                                        }
@@ -297,17 +308,13 @@ static void tlv_initialize_descriptors(const struct mach_header* mh)
        }
 }
 
-// called by dyld when a image is loaded
-static const char* tlv_load_notification(enum dyld_image_states state, uint32_t infoCount, const struct dyld_image_info info[])
+
+static void tlv_load_notification(const struct mach_header* mh, intptr_t slide)
 {
-       // this is called on all images, even those without TLVs, so we want
-       // this to be fast.  The linker sets MH_HAS_TLV_DESCRIPTORS so we don't
-       // have to search images just to find the don't have TLVs.
-       for (uint32_t i=0; i < infoCount; ++i) {
-               if ( info[i].imageLoadAddress->flags & MH_HAS_TLV_DESCRIPTORS )
-                       tlv_initialize_descriptors(info[i].imageLoadAddress);
-       }
-       return NULL;
+       // This is called on all images, even those without TLVs. So we want this to be fast.
+       // The linker sets MH_HAS_TLV_DESCRIPTORS so we don't have to search images just to find the don't have TLVs.
+       if ( mh->flags & MH_HAS_TLV_DESCRIPTORS )
+               tlv_initialize_descriptors(mh);
 }
 
 
@@ -360,7 +367,6 @@ void dyld_enumerate_tlv_storage(dyld_tlv_state_change_handler handler)
 // destructor key to come before the deallocation key.
 //
 
-typedef void (*TermFunc)(void*);
 struct TLVTerminatorListEntry
 {
     TermFunc    termFunc;
@@ -391,10 +397,10 @@ void _tlv_atexit(TermFunc func, void* objAddr)
         pthread_setspecific(tlv_terminators_key, list);
     }
     else {
-        if ( list->allocCount == list->allocCount ) {
+        if ( list->useCount == list->allocCount ) {
             // handle resizing allocation 
             uint32_t newAllocCount = list->allocCount * 2;
-            uint32_t newAllocSize = offsetof(struct TLVTerminatorList, entries[newAllocCount]);
+            size_t newAllocSize = offsetof(struct TLVTerminatorList, entries[newAllocCount]);
             struct TLVTerminatorList* newlist = (struct TLVTerminatorList*)malloc(newAllocSize);
             newlist->allocCount = newAllocCount;
             newlist->useCount = list->useCount;
@@ -411,13 +417,14 @@ void _tlv_atexit(TermFunc func, void* objAddr)
     }
 }
 
-// called by pthreads when the current thread is going way and 
+// 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;
-    for(uint32_t i=0; i < list->useCount; ++i) {
-        struct TLVTerminatorListEntry* entry = &list->entries[i];
+    // 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);
         }
@@ -425,6 +432,16 @@ static void tlv_finalize(void* storage)
     free(storage);
 }
 
+// <rdar://problem/13741816>
+// called by exit() before it calls cxa_finalize() so that thread_local
+// objects are destroyed before global objects.
+void _tlv_exit()
+{
+       void* termFuncs = pthread_getspecific(tlv_terminators_key);
+       if ( termFuncs != NULL )
+               tlv_finalize(termFuncs);
+}
+
 
 __attribute__((visibility("hidden")))
 void tlv_initializer()
@@ -435,7 +452,8 @@ void tlv_initializer()
     (void)pthread_key_create(&tlv_terminators_key, &tlv_finalize);
        
     // register with dyld for notification when images are loaded
-    dyld_register_image_state_change_handler(dyld_image_state_bound, true, tlv_load_notification);
+       _dyld_register_func_for_add_image(tlv_load_notification);
+
 }
 
 
@@ -446,9 +464,9 @@ void _tlv_bootstrap()
 }
 
 
-// __i386__ || __x86_64__
+
 #else
-// !(__i386__ || __x86_64__)
+
 
 
 void dyld_register_tlv_state_change_handler(enum dyld_tlv_states state, dyld_tlv_state_change_handler handler)
@@ -459,13 +477,21 @@ void dyld_enumerate_tlv_storage(dyld_tlv_state_change_handler handler)
 {
 }
 
+void _tlv_exit()
+{
+}
+
+void _tlv_atexit(TermFunc func, void* objAddr)
+{
+}
+
 __attribute__((visibility("hidden")))
 void tlv_initializer()
 {
 }
 
 
-// !(__i386__ || __x86_64__)
-#endif
+
+#endif // __has_feature(tls)