6988439: Parallel Class Loading test deadlock involving MethodData_lock and Pending List Lock
Summary: Don't acquire methodData_lock while holding pending list lock
Reviewed-by: kvn, never, ysr
--- a/hotspot/src/share/vm/oops/instanceRefKlass.cpp Thu Dec 09 20:12:06 2010 -0500
+++ b/hotspot/src/share/vm/oops/instanceRefKlass.cpp Fri Dec 10 12:13:03 2010 -0500
@@ -457,6 +457,11 @@
}
}
+bool instanceRefKlass::owns_pending_list_lock(JavaThread* thread) {
+ Handle h_lock(thread, java_lang_ref_Reference::pending_list_lock());
+ return ObjectSynchronizer::current_thread_holds_lock(thread, h_lock);
+}
+
void instanceRefKlass::acquire_pending_list_lock(BasicLock *pending_list_basic_lock) {
// we may enter this with pending exception set
PRESERVE_EXCEPTION_MARK; // exceptions are never thrown, needed for TRAPS argument
--- a/hotspot/src/share/vm/oops/instanceRefKlass.hpp Thu Dec 09 20:12:06 2010 -0500
+++ b/hotspot/src/share/vm/oops/instanceRefKlass.hpp Fri Dec 10 12:13:03 2010 -0500
@@ -89,6 +89,7 @@
static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock);
static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock);
+ static bool owns_pending_list_lock(JavaThread* thread);
// Update non-static oop maps so 'referent', 'nextPending' and
// 'discovered' will look like non-oops
--- a/hotspot/src/share/vm/oops/methodOop.cpp Thu Dec 09 20:12:06 2010 -0500
+++ b/hotspot/src/share/vm/oops/methodOop.cpp Fri Dec 10 12:13:03 2010 -0500
@@ -309,6 +309,12 @@
// Build a methodDataOop object to hold information about this method
// collected in the interpreter.
void methodOopDesc::build_interpreter_method_data(methodHandle method, TRAPS) {
+ // Do not profile method if current thread holds the pending list lock,
+ // which avoids deadlock for acquiring the MethodData_lock.
+ if (instanceRefKlass::owns_pending_list_lock((JavaThread*)THREAD)) {
+ return;
+ }
+
// Grab a lock here to prevent multiple
// methodDataOops from being created.
MutexLocker ml(MethodData_lock, THREAD);