src/share/vm/memory/metaspace.cpp

rev 4526 : 8013129: Possible deadlock with Metaspace locks due to mixed usage of safepoint aware and non-safepoint aware locking
Summary: Change Metaspace::deallocate to take lock with _no_safepoint_check_flag
Reviewed-by:

*** 2943,2953 ****
  
  void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
    if (SafepointSynchronize::is_at_safepoint()) {
      assert(Thread::current()->is_VM_thread(), "should be the VM thread");
      // Don't take Heap_lock
!     MutexLocker ml(vsm()->lock());
      if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
        // Dark matter.  Too small for dictionary.
  #ifdef ASSERT
        Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
  #endif
--- 2943,2953 ----
  
  void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
    if (SafepointSynchronize::is_at_safepoint()) {
      assert(Thread::current()->is_VM_thread(), "should be the VM thread");
      // Don't take Heap_lock
!     MutexLockerEx ml(vsm()->lock(), Mutex::_no_safepoint_check_flag);
      if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
        // Dark matter.  Too small for dictionary.
  #ifdef ASSERT
        Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
  #endif
*** 2957,2967 ****
         class_vsm()->deallocate(ptr, word_size);
      } else {
        vsm()->deallocate(ptr, word_size);
      }
    } else {
!     MutexLocker ml(vsm()->lock());
  
      if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
        // Dark matter.  Too small for dictionary.
  #ifdef ASSERT
        Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
--- 2957,2967 ----
         class_vsm()->deallocate(ptr, word_size);
      } else {
        vsm()->deallocate(ptr, word_size);
      }
    } else {
!     MutexLockerEx ml(vsm()->lock(), Mutex::_no_safepoint_check_flag);
  
      if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
        // Dark matter.  Too small for dictionary.
  #ifdef ASSERT
        Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);