874 }

   875 

   876 //////////////////////////////////////////////////////////////////////////////

   877 // thread local storage

   878 

   879 // Restore the thread pointer if the destructor is called. This is in case

   880 // someone from JNI code sets up a destructor with pthread_key_create to run

   881 // detachCurrentThread on thread death. Unless we restore the thread pointer we

   882 // will hang or crash. When detachCurrentThread is called the key will be set

   883 // to null and we will not be called again. If detachCurrentThread is never

   884 // called we could loop forever depending on the pthread implementation.

   885 static void restore_thread_pointer(void* p) {

   886   Thread* thread = (Thread*) p;

   887   os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);

   888 }

   889 

   890 int os::allocate_thread_local_storage() {

   891   pthread_key_t key;

   892   int rslt = pthread_key_create(&key, restore_thread_pointer);

   893   assert(rslt == 0, "cannot allocate thread local storage");

   894   return (int)key;

   895 }

   896 

   897 // Note: This is currently not used by VM, as we don't destroy TLS key

   898 // on VM exit.

   899 void os::free_thread_local_storage(int index) {

   900   int rslt = pthread_key_delete((pthread_key_t)index);

   901   assert(rslt == 0, "invalid index");

   902 }

   903 

   904 void os::thread_local_storage_at_put(int index, void* value) {

   905   int rslt = pthread_setspecific((pthread_key_t)index, value);

   906   assert(rslt == 0, "pthread_setspecific failed");

   907 }

   908 

   909 extern "C" Thread* get_thread() {

   910   return ThreadLocalStorage::thread();