src/share/vm/gc_implementation/g1/concurrentMarkThread.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:

*** 145,160 ****
              gclog_or_tty->stamp(PrintGCTimeStamps);
              gclog_or_tty->print_cr("[GC concurrent-mark-restart-for-overflow]");
            }
          }
        } while (cm()->restart_for_overflow());
-       double counting_start_time = os::elapsedVTime();
- 
-       // YSR: These look dubious (i.e. redundant) !!! FIX ME
-       slt()->manipulatePLL(SurrogateLockerThread::acquirePLL);
-       slt()->manipulatePLL(SurrogateLockerThread::releaseAndNotifyPLL);
  
        if (!cm()->has_aborted()) {
          double count_start_sec = os::elapsedTime();
          if (PrintGC) {
            gclog_or_tty->date_stamp(PrintGCDateStamps);
            gclog_or_tty->stamp(PrintGCTimeStamps);
--- 145,156 ----
              gclog_or_tty->stamp(PrintGCTimeStamps);
              gclog_or_tty->print_cr("[GC concurrent-mark-restart-for-overflow]");
            }
          }
        } while (cm()->restart_for_overflow());
  
+       double counting_start_time = os::elapsedVTime();
        if (!cm()->has_aborted()) {
          double count_start_sec = os::elapsedTime();
          if (PrintGC) {
            gclog_or_tty->date_stamp(PrintGCDateStamps);
            gclog_or_tty->stamp(PrintGCTimeStamps);
*** 173,182 ****
--- 169,179 ----
              gclog_or_tty->print_cr("[GC concurrent-count-end, %1.7lf]",
                                     count_end_sec - count_start_sec);
            }
          }
        }
+ 
        double end_time = os::elapsedVTime();
        _vtime_count_accum += (end_time - counting_start_time);
        // Update the total virtual time before doing this, since it will try
        // to measure it to get the vtime for this marking.  We purposely
        // neglect the presumably-short "completeCleanup" phase here.
*** 333,347 ****
    }
    set_in_progress();
    clear_started();
  }
  
! // Note: this method, although exported by the ConcurrentMarkSweepThread,
  // which is a non-JavaThread, can only be called by a JavaThread.
  // Currently this is done at vm creation time (post-vm-init) by the
  // main/Primordial (Java)Thread.
! // XXX Consider changing this in the future to allow the CMS thread
  // itself to create this thread?
  void ConcurrentMarkThread::makeSurrogateLockerThread(TRAPS) {
    assert(_slt == NULL, "SLT already created");
    _slt = SurrogateLockerThread::make(THREAD);
  }
--- 330,346 ----
    }
    set_in_progress();
    clear_started();
  }
  
! // Note: this method, although exported by the ConcurrentMarkThread,
  // which is a non-JavaThread, can only be called by a JavaThread.
  // Currently this is done at vm creation time (post-vm-init) by the
  // main/Primordial (Java)Thread.
! // XXX Consider changing this in the future to allow the CM thread
  // itself to create this thread?
  void ConcurrentMarkThread::makeSurrogateLockerThread(TRAPS) {
+   assert(UseG1GC, "SLT thread needed only for concurrent GC");
+   assert(THREAD->is_Java_thread(), "must be a Java thread");
    assert(_slt == NULL, "SLT already created");
    _slt = SurrogateLockerThread::make(THREAD);
  }