src/share/vm/gc_implementation/g1/concurrentMark.cpp

rev 6345 : 8040803: G1: Concurrent mark hangs when mark stack overflows
Reviewed-by: TDB

*** 976,995 ****
    }
  
    if (concurrent()) {
      SuspendibleThreadSet::leave();
    }
!   _first_overflow_barrier_sync.enter();
    if (concurrent()) {
      SuspendibleThreadSet::join();
    }
    // at this point everyone should have synced up and not be doing any
    // more work
  
    if (verbose_low()) {
      gclog_or_tty->print_cr("[%u] leaving first barrier", worker_id);
    }
  
    // If we're executing the concurrent phase of marking, reset the marking
    // state; otherwise the marking state is reset after reference processing,
    // during the remark pause.
    // If we reset here as a result of an overflow during the remark we will
--- 976,1007 ----
    }
  
    if (concurrent()) {
      SuspendibleThreadSet::leave();
    }
! 
!   bool barrier_aborted = !_first_overflow_barrier_sync.enter();
! 
    if (concurrent()) {
      SuspendibleThreadSet::join();
    }
    // at this point everyone should have synced up and not be doing any
    // more work
  
    if (verbose_low()) {
+     if (barrier_aborted) {
+       gclog_or_tty->print_cr("[%u] aborted first barrier", worker_id);
+     } else {
        gclog_or_tty->print_cr("[%u] leaving first barrier", worker_id);
      }
+   }
+ 
+   if (barrier_aborted) {
+     // If the barrier aborted we ignore the overflow condition and
+     // just abort the whole marking phase as quickly as possible.
+     return;
+   }
  
    // If we're executing the concurrent phase of marking, reset the marking
    // state; otherwise the marking state is reset after reference processing,
    // during the remark pause.
    // If we reset here as a result of an overflow during the remark we will
*** 1024,1042 ****
    }
  
    if (concurrent()) {
      SuspendibleThreadSet::leave();
    }
!   _second_overflow_barrier_sync.enter();
    if (concurrent()) {
      SuspendibleThreadSet::join();
    }
    // at this point everything should be re-initialized and ready to go
  
    if (verbose_low()) {
      gclog_or_tty->print_cr("[%u] leaving second barrier", worker_id);
    }
  }
  
  #ifndef PRODUCT
  void ForceOverflowSettings::init() {
    _num_remaining = G1ConcMarkForceOverflow;
--- 1036,1060 ----
    }
  
    if (concurrent()) {
      SuspendibleThreadSet::leave();
    }
! 
!   bool barrier_aborted = !_second_overflow_barrier_sync.enter();
! 
    if (concurrent()) {
      SuspendibleThreadSet::join();
    }
    // at this point everything should be re-initialized and ready to go
  
    if (verbose_low()) {
+     if (barrier_aborted) {
+       gclog_or_tty->print_cr("[%u] aborted second barrier", worker_id);
+     } else {
        gclog_or_tty->print_cr("[%u] leaving second barrier", worker_id);
      }
+   }
  }
  
  #ifndef PRODUCT
  void ForceOverflowSettings::init() {
    _num_remaining = G1ConcMarkForceOverflow;
*** 3238,3247 ****
--- 3256,3267 ----
    // Empty mark stack
    reset_marking_state();
    for (uint i = 0; i < _max_worker_id; ++i) {
      _tasks[i]->clear_region_fields();
    }
+   _first_overflow_barrier_sync.abort();
+   _second_overflow_barrier_sync.abort();
    _has_aborted = true;
  
    SATBMarkQueueSet& satb_mq_set = JavaThread::satb_mark_queue_set();
    satb_mq_set.abandon_partial_marking();
    // This can be called either during or outside marking, we'll read