jvmtiError
JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) {
#ifdef ASSERT
uint32_t debug_bits = 0;
#endif
assert((SafepointSynchronize::is_at_safepoint() ||
is_thread_fully_suspended(java_thread, false, &debug_bits)),
"at safepoint or target thread is suspended");
oop obj = NULL;
ObjectMonitor *mon = java_thread->current_waiting_monitor();
if (mon == NULL) {
// thread is not doing an Object.wait() call
mon = java_thread->current_pending_monitor();
if (mon != NULL) {
// The thread is trying to enter() or raw_enter() an ObjectMonitor.
obj = (oop)mon->object();
// If obj == NULL, then ObjectMonitor is raw which doesn't count
// as contended for this API
}
// implied else: no contended ObjectMonitor
} else {
// thread is doing an Object.wait() call
obj = (oop)mon->object();
assert(obj != NULL, "Object.wait() should have an object");
}
if (obj == NULL) {
*monitor_ptr = NULL;
} else {
HandleMark hm;
Handle hobj(obj);
*monitor_ptr = jni_reference(calling_thread, hobj);
}
return JVMTI_ERROR_NONE;
}
void DeadlockCycle::print_on(outputStream* st) const {
st->cr();
st->print_cr("Found one Java-level deadlock:");
st->print("=============================");
JavaThread* currentThread;
ObjectMonitor* waitingToLockMonitor;
oop waitingToLockBlocker;
int len = _threads->length();
for (int i = 0; i < len; i++) {
currentThread = _threads->at(i);
waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor();
waitingToLockBlocker = currentThread->current_park_blocker();
st->cr();
st->print_cr("\"%s\":", currentThread->get_thread_name());
const char* owner_desc = ",\n which is held by";
if (waitingToLockMonitor != NULL) {
st->print(" waiting to lock monitor " INTPTR_FORMAT, waitingToLockMonitor);
oop obj = (oop)waitingToLockMonitor->object();
if (obj != NULL) {
st->print(" (object "INTPTR_FORMAT ", a %s)", (address)obj,
(instanceKlass::cast(obj->klass()))->external_name());
if (!currentThread->current_pending_monitor_is_from_java()) {
owner_desc = "\n in JNI, which is held by";
}
} else {
// No Java object associated - a JVMTI raw monitor
owner_desc = " (JVMTI raw monitor),\n which is held by";
}
currentThread = Threads::owning_thread_from_monitor_owner(
(address)waitingToLockMonitor->owner(), false /* no locking needed */);
} else {
st->print(" waiting for ownable synchronizer " INTPTR_FORMAT ", (a %s)",
(address)waitingToLockBlocker,
(instanceKlass::cast(waitingToLockBlocker->klass()))->external_name());
assert(waitingToLockBlocker->is_a(SystemDictionary::abstract_ownable_synchronizer_klass()),
"Must be an AbstractOwnableSynchronizer");
oop ownerObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker);
currentThread = java_lang_Thread::thread(ownerObj);
}
st->print("%s \"%s\"", owner_desc, currentThread->get_thread_name());
}
st->cr();
st->cr();
// Print stack traces
bool oldJavaMonitorsInStackTrace = JavaMonitorsInStackTrace;
JavaMonitorsInStackTrace = true;
st->print_cr("Java stack information for the threads listed above:");
st->print_cr("===================================================");
for (int j = 0; j < len; j++) {
currentThread = _threads->at(j);
st->print_cr("\"%s\":", currentThread->get_thread_name());
currentThread->print_stack_on(st);
}
JavaMonitorsInStackTrace = oldJavaMonitorsInStackTrace;
}
// Save JNI local handles for any objects that this frame owns.
jvmtiError
JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread,
javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, int stack_depth) {
jvmtiError err = JVMTI_ERROR_NONE;
ResourceMark rm;
GrowableArray<MonitorInfo*>* mons = jvf->monitors();
if (mons->is_empty()) {
return err; // this javaVFrame holds no monitors
}
HandleMark hm;
oop wait_obj = NULL;
{
// save object of current wait() call (if any) for later comparison
ObjectMonitor *mon = java_thread->current_waiting_monitor();
if (mon != NULL) {
wait_obj = (oop)mon->object();
}
}
oop pending_obj = NULL;
{
// save object of current enter() call (if any) for later comparison
ObjectMonitor *mon = java_thread->current_pending_monitor();
if (mon != NULL) {
pending_obj = (oop)mon->object();
}
}
for (int i = 0; i < mons->length(); i++) {
MonitorInfo *mi = mons->at(i);
if (mi->owner_is_scalar_replaced()) continue;
oop obj = mi->owner();
if (obj == NULL) {
// this monitor doesn't have an owning object so skip it
continue;
}
if (wait_obj == obj) {
// the thread is waiting on this monitor so it isn't really owned
continue;
}
if (pending_obj == obj) {
// the thread is pending on this monitor so it isn't really owned
continue;
}
if (owned_monitors_list->length() > 0) {
// Our list has at least one object on it so we have to check
// for recursive object locking
bool found = false;
for (int j = 0; j < owned_monitors_list->length(); j++) {
jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor;
oop check = JNIHandles::resolve(jobj);
if (check == obj) {
found = true; // we found the object
break;
}
}
if (found) {
// already have this object so don't include it
continue;
}
}
// add the owning object to our list
jvmtiMonitorStackDepthInfo *jmsdi;
err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
if (err != JVMTI_ERROR_NONE) {
return err;
}
Handle hobj(obj);
jmsdi->monitor = jni_reference(calling_thread, hobj);
jmsdi->stack_depth = stack_depth;
owned_monitors_list->append(jmsdi);
}
return err;
}
// Save global JNI handles for any objects that this thread owns.
void javaVFrame::save_lock_entries(GrowableArray<jobject>* handle_list) {
ResourceMark rm;
GrowableArray<MonitorInfo*>* mons = monitors();
if (mons->is_empty()) {
return; // this javaVFrame holds no monitors
}
HandleMark hm;
oop wait_obj = NULL;
{
// save object of current wait() call (if any) for later comparison
ObjectMonitor *mon = thread()->current_waiting_monitor();
if (mon != NULL) {
wait_obj = (oop)mon->object();
}
}
oop pending_obj = NULL;
{
// save object of current enter() call (if any) for later comparison
ObjectMonitor *mon = thread()->current_pending_monitor();
if (mon != NULL) {
pending_obj = (oop)mon->object();
}
}
for (int i = 0; i < mons->length(); i++) {
MonitorInfo *mi = mons->at(i);
oop obj = mi->owner();
if (obj == NULL) {
// this monitor doesn't have an owning object so skip it
continue;
}
if (wait_obj == obj) {
// the thread is waiting on this monitor so it isn't really owned
continue;
}
if (pending_obj == obj) {
// the thread is pending on this monitor so it isn't really owned
continue;
}
if (handle_list->length() > 0) {
// Our list has at least one object on it so we have to check
// for recursive object locking
bool found = false;
for (int j = 0; j < handle_list->length(); j++) {
jobject jobj = handle_list->at(j);
oop check = JNIHandles::resolve(jobj);
if (check == obj) {
found = true; // we found the object
break;
}
}
if (found) {
// already have this object so don't include it
continue;
}
}
// add the owning object to our list
Handle hobj(obj);
jobject jobj = (jobject)JNIHandles::make_global(hobj);
handle_list->append(jobj);
}
}