src/share/vm/gc/shenandoah/shenandoahConcurrentThread.cpp

rev 14452 : [mq]: onebitmap.patch

*** 160,169 ****
--- 160,181 ----
  
    GCIdMark gc_id_mark;
    TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters());
    TraceMemoryManagerStats tmms(false, GCCause::_no_cause_specified);
  
+   // Mark requires clean bitmaps. Clear them here, before diving into STW.
+   // There is a potential race from this moment on to TAMS reset in init mark: the bitmaps
+   // would be clear, but TAMS not yet updated.
+   {
+     GCTraceTime(Info, gc) time("Concurrent cleanup", gc_timer, GCCause::_no_gc, true);
+     ShenandoahGCPhase phase(ShenandoahPhaseTimings::conc_cleanup);
+     ShenandoahGCPhase phase_reset(ShenandoahPhaseTimings::conc_cleanup_reset_bitmaps);
+     WorkGang *workers = heap->workers();
+     ShenandoahPushWorkerScope scope(workers, ConcGCThreads);
+     heap->reset_mark_bitmap(workers);
+   }
+ 
    // Start initial mark under STW:
    {
      // Workers are setup by VM_ShenandoahInitMark
      TraceCollectorStats tcs(heap->monitoring_support()->stw_collection_counters());
      ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause_gross);
*** 310,319 ****
--- 322,342 ----
        ShenandoahGCPhase total(ShenandoahPhaseTimings::total_pause_gross);
        ShenandoahGCPhase final_update_refs_phase(ShenandoahPhaseTimings::final_update_refs_gross);
        VM_ShenandoahFinalUpdateRefs final_update_refs;
        VMThread::execute(&final_update_refs);
      }
+ 
+     if (do_it) {
+       GCTraceTime(Info, gc) time("Concurrent cleanup", gc_timer, GCCause::_no_gc, true);
+       ShenandoahGCPhase phase(ShenandoahPhaseTimings::conc_cleanup);
+       ShenandoahGCPhase phase_recycle(ShenandoahPhaseTimings::conc_cleanup_recycle);
+       heap->recycle_trash();
+     }
+ 
+     // Allocations happen during bitmap cleanup, record peak after the phase:
+     heap->shenandoahPolicy()->record_peak_occupancy();
+ 
    } else {
      // If update-refs were skipped, need to do another verification pass after evacuation.
      if (ShenandoahVerify && !check_cancellation()) {
        VM_ShenandoahVerifyHeapAfterEvacuation verify_after_evacuation;
        VMThread::execute(&verify_after_evacuation);
*** 325,354 ****
  
    if (clear_full_gc) {
      reset_full_gc();
    }
  
-   {
-     GCTraceTime(Info, gc) time("Concurrent cleanup", gc_timer, GCCause::_no_gc, true);
-     ShenandoahGCPhase phase(ShenandoahPhaseTimings::conc_cleanup);
- 
-     {
-       ShenandoahGCPhase phase_recycle(ShenandoahPhaseTimings::conc_cleanup_recycle);
-       heap->recycle_trash();
-     }
- 
-     {
-       ShenandoahGCPhase phase_reset(ShenandoahPhaseTimings::conc_cleanup_reset_bitmaps);
-       WorkGang *workers = heap->workers();
-       ShenandoahPushWorkerScope scope(workers, ConcGCThreads);
-       heap->reset_next_mark_bitmap(workers);
-     }
-   }
- 
-   // Allocations happen during bitmap cleanup, record peak after the phase:
-   heap->shenandoahPolicy()->record_peak_occupancy();
- 
    // Cycle is complete
    heap->shenandoahPolicy()->record_cycle_end();
  
    // TODO: Call this properly with Shenandoah*CycleMark
    heap->set_used_at_last_gc();
--- 348,357 ----