src/share/vm/gc_implementation/shared/concurrentGCThread.cpp

rev 2755 : 7099824: G1: we should take the pending list lock before doing the remark pause
Summary: Acquire the pending list lock in the prologue method of G1's
concurrent VM_Operation and release the lock in the epilogue() method.
The locking/unlocking order of the pending list lock and the Heap_lock
should match that in the prologue and epilogue methods of VM_GC_Operation.
Reviewed-by:

*** 222,231 ****
--- 222,233 ----
  
  void SurrogateLockerThread::manipulatePLL(SLT_msg_type msg) {
    MutexLockerEx x(&_monitor, Mutex::_no_safepoint_check_flag);
    assert(_buffer == empty, "Should be empty");
    assert(msg != empty, "empty message");
+   assert(!Heap_lock->owned_by_self(), "Heap_lock owned by requesting thread");
+ 
    _buffer = msg;
    while (_buffer != empty) {
      _monitor.notify();
      _monitor.wait(Mutex::_no_safepoint_check_flag);
    }