archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-08-28 15:24:43 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

8173658: JvmtiExport::post_class_unload() is broken for non-JavaThread initiators

Browse source 
Call extension ClassUnload event as a deferred event from the ServiceThread and remove unsafe arguments

Reviewed-by: sspitsyn, dholmes
This commit is contained in:
Coleen Phillimore 2019-12-02 09:02:17 -05:00
parent b1d915ef80
commit d1d57d9446
9 changed files with 86 additions and 51 deletions
Download patch file Download diff file Expand all files Collapse all files

54
src/hotspot/share/prims/jvmtiExport.cpp
View file

@ -1349,20 +1349,27 @@ void JvmtiExport::post_class_unload(Klass* klass) {
if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
return;
}
Thread *thread = Thread::current();
// postings to the service thread so that it can perform them in a safe
// context and in-order.
MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
ResourceMark rm;
// JvmtiDeferredEvent copies the string.
JvmtiDeferredEvent event = JvmtiDeferredEvent::class_unload_event(klass->name()->as_C_string());
JvmtiDeferredEventQueue::enqueue(event);
}
void JvmtiExport::post_class_unload_internal(const char* name) {
if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
return;
}
assert(Thread::current()->is_service_thread(), "must be called from ServiceThread");
JavaThread *thread = JavaThread::current();
HandleMark hm(thread);
EVT_TRIG_TRACE(EXT_EVENT_CLASS_UNLOAD, ("[?] Trg Class Unload triggered" ));
if (JvmtiEventController::is_enabled((jvmtiEvent)EXT_EVENT_CLASS_UNLOAD)) {
assert(thread->is_VM_thread(), "wrong thread");
// get JavaThread for whom we are proxy
Thread *calling_thread = ((VMThread *)thread)->vm_operation()->calling_thread();
if (!calling_thread->is_Java_thread()) {
// cannot post an event to a non-JavaThread
return;
}
JavaThread *real_thread = (JavaThread *)calling_thread;
JvmtiEnvIterator it;
for (JvmtiEnv* env = it.first(); env != NULL; env = it.next(env)) {
@ -1370,33 +1377,14 @@ void JvmtiExport::post_class_unload(Klass* klass) {
continue;
}
if (env->is_enabled((jvmtiEvent)EXT_EVENT_CLASS_UNLOAD)) {
EVT_TRACE(EXT_EVENT_CLASS_UNLOAD, ("[?] Evt Class Unload sent %s",
klass==NULL? "NULL" : klass->external_name() ));
// do everything manually, since this is a proxy - needs special care
JNIEnv* jni_env = real_thread->jni_environment();
jthread jt = (jthread)JNIHandles::make_local(real_thread, real_thread->threadObj());
jclass jk = (jclass)JNIHandles::make_local(real_thread, klass->java_mirror());
// Before we call the JVMTI agent, we have to set the state in the
// thread for which we are proxying.
JavaThreadState prev_state = real_thread->thread_state();
assert(((Thread *)real_thread)->is_ConcurrentGC_thread() ||
(real_thread->is_Java_thread() && prev_state == _thread_blocked),
"should be ConcurrentGCThread or JavaThread at safepoint");
real_thread->set_thread_state(_thread_in_native);
EVT_TRACE(EXT_EVENT_CLASS_UNLOAD, ("[?] Evt Class Unload sent %s", name));
JvmtiEventMark jem(thread);
JvmtiJavaThreadEventTransition jet(thread);
jvmtiExtensionEvent callback = env->ext_callbacks()->ClassUnload;
if (callback != NULL) {
(*callback)(env->jvmti_external(), jni_env, jt, jk);
(*callback)(env->jvmti_external(), jem.jni_env(), name);
}
assert(real_thread->thread_state() == _thread_in_native,
"JavaThread should be in native");
real_thread->set_thread_state(prev_state);
JNIHandles::destroy_local(jk);
JNIHandles::destroy_local(jt);
}
}
}