src/share/vm/classfile/systemDictionary.cpp

rev 12604 : 8173743: Failures during class definition can lead to memory leaks in metaspace
Reviewed-by: dholmes, coleenp, acorn, ddmitriev

*** 1150,1174 ****
  
    assert(k.not_null(), "no klass created");
    Symbol* h_name = k->name();
    assert(class_name == NULL || class_name == h_name, "name mismatch");
  
-   bool define_succeeded = false;
    // Add class just loaded
    // If a class loader supports parallel classloading handle parallel define requests
    // find_or_define_instance_class may return a different InstanceKlass
    if (is_parallelCapable(class_loader)) {
!     instanceKlassHandle defined_k = find_or_define_instance_class(h_name, class_loader, k, CHECK_NULL);
!     if (k() == defined_k()) {
!       // we have won over other concurrent threads (if any) that are
!       // competing to define the same class.
!       define_succeeded = true;
!     }
      k = defined_k;
    } else {
!     define_instance_class(k, CHECK_NULL);
!     define_succeeded = true;
    }
  
    // Make sure we have an entry in the SystemDictionary on success
    debug_only( {
      MutexLocker mu(SystemDictionary_lock, THREAD);
--- 1150,1178 ----
  
    assert(k.not_null(), "no klass created");
    Symbol* h_name = k->name();
    assert(class_name == NULL || class_name == h_name, "name mismatch");
  
    // Add class just loaded
    // If a class loader supports parallel classloading handle parallel define requests
    // find_or_define_instance_class may return a different InstanceKlass
    if (is_parallelCapable(class_loader)) {
!     instanceKlassHandle defined_k = find_or_define_instance_class(h_name, class_loader, k, THREAD);
!     if (defined_k.not_null() && defined_k() != k()) {
!       // If a parallel capable class loader already defined this class, register 'k' for cleanup.
!       loader_data->add_to_deallocate_list(k());
        k = defined_k;
+     }
    } else {
!     define_instance_class(k, THREAD);
!   }
! 
!   // If defining the class throws an exception register 'k' for cleanup.
!   if (HAS_PENDING_EXCEPTION) {
!     assert(k.not_null(), "Must have an instance klass here!");
!     loader_data->add_to_deallocate_list(k());
!     return NULL;
    }
  
    // Make sure we have an entry in the SystemDictionary on success
    debug_only( {
      MutexLocker mu(SystemDictionary_lock, THREAD);