1.1 --- a/src/share/vm/oops/instanceKlass.cpp Mon Oct 21 17:26:46 2013 -0700
1.2 +++ b/src/share/vm/oops/instanceKlass.cpp Tue Oct 22 14:29:02 2013 -0700
1.3 @@ -498,13 +498,27 @@
1.4
1.5 oop InstanceKlass::init_lock() const {
1.6 // return the init lock from the mirror
1.7 - return java_lang_Class::init_lock(java_mirror());
1.8 + oop lock = java_lang_Class::init_lock(java_mirror());
1.9 + assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
1.10 + "only fully initialized state can have a null lock");
1.11 + return lock;
1.12 +}
1.13 +
1.14 +// Set the initialization lock to null so the object can be GC'ed. Any racing
1.15 +// threads to get this lock will see a null lock and will not lock.
1.16 +// That's okay because they all check for initialized state after getting
1.17 +// the lock and return.
1.18 +void InstanceKlass::fence_and_clear_init_lock() {
1.19 + // make sure previous stores are all done, notably the init_state.
1.20 + OrderAccess::storestore();
1.21 + java_lang_Class::set_init_lock(java_mirror(), NULL);
1.22 + assert(!is_not_initialized(), "class must be initialized now");
1.23 }
1.24
1.25 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
1.26 EXCEPTION_MARK;
1.27 oop init_lock = this_oop->init_lock();
1.28 - ObjectLocker ol(init_lock, THREAD);
1.29 + ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
1.30
1.31 // abort if someone beat us to the initialization
1.32 if (!this_oop->is_not_initialized()) return; // note: not equivalent to is_initialized()
1.33 @@ -523,6 +537,7 @@
1.34 } else {
1.35 // linking successfull, mark class as initialized
1.36 this_oop->set_init_state (fully_initialized);
1.37 + this_oop->fence_and_clear_init_lock();
1.38 // trace
1.39 if (TraceClassInitialization) {
1.40 ResourceMark rm(THREAD);
1.41 @@ -649,7 +664,7 @@
1.42 // verification & rewriting
1.43 {
1.44 oop init_lock = this_oop->init_lock();
1.45 - ObjectLocker ol(init_lock, THREAD);
1.46 + ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
1.47 // rewritten will have been set if loader constraint error found
1.48 // on an earlier link attempt
1.49 // don't verify or rewrite if already rewritten
1.50 @@ -772,7 +787,7 @@
1.51 // Step 1
1.52 {
1.53 oop init_lock = this_oop->init_lock();
1.54 - ObjectLocker ol(init_lock, THREAD);
1.55 + ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
1.56
1.57 Thread *self = THREAD; // it's passed the current thread
1.58
1.59 @@ -920,8 +935,9 @@
1.60
1.61 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
1.62 oop init_lock = this_oop->init_lock();
1.63 - ObjectLocker ol(init_lock, THREAD);
1.64 + ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
1.65 this_oop->set_init_state(state);
1.66 + this_oop->fence_and_clear_init_lock();
1.67 ol.notify_all(CHECK);
1.68 }
1.69
