src/hotspot/share/gc/shenandoah/shenandoahPacer.hpp

@@ -25,13 +25,30 @@
  #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHPACER_HPP
  #define SHARE_GC_SHENANDOAH_SHENANDOAHPACER_HPP
  
  #include "gc/shenandoah/shenandoahNumberSeq.hpp"
  #include "gc/shenandoah/shenandoahPadding.hpp"
+ #include "gc/shenandoah/shenandoahSharedVariables.hpp"
  #include "memory/allocation.hpp"
+ #include "runtime/task.hpp"
  
  class ShenandoahHeap;
+ class ShenandoahPacer;
+ 
+ 
+ // Periodic task to notify blocked paced waiters.
+ class ShenandoahPeriodicPacerNotifyTask : public PeriodicTask {
+ private:
+   ShenandoahPacer* const _pacer;
+ public:
+   explicit ShenandoahPeriodicPacerNotifyTask(ShenandoahPacer* pacer) :
+     PeriodicTask(PeriodicTask::min_interval),
+     _pacer(pacer) { }
+ 
+   void task() override;
+ };
+ 
  
  #define PACING_PROGRESS_UNINIT (-1)
  #define PACING_PROGRESS_ZERO   ( 0)
  
  /**

@@ -45,10 +62,11 @@
    ShenandoahHeap* _heap;
    double _last_time;
    TruncatedSeq* _progress_history;
    Monitor* _wait_monitor;
    ShenandoahSharedFlag _need_notify_waiters;
+   ShenandoahPeriodicPacerNotifyTask _notify_waiters_task;
  
    // Set once per phase
    volatile intptr_t _epoch;
    volatile double _tax_rate;
  

@@ -61,19 +79,22 @@
    shenandoah_padding(2);
    volatile intptr_t _progress;
    shenandoah_padding(3);
  
  public:
-   ShenandoahPacer(ShenandoahHeap* heap) :
+   explicit ShenandoahPacer(ShenandoahHeap* heap) :
            _heap(heap),
            _last_time(os::elapsedTime()),
            _progress_history(new TruncatedSeq(5)),
            _wait_monitor(new Monitor(Mutex::safepoint-1, "ShenandoahWaitMonitor_lock", true)),
+           _notify_waiters_task(this),
            _epoch(0),
            _tax_rate(1),
            _budget(0),
-           _progress(PACING_PROGRESS_UNINIT) {}
+           _progress(PACING_PROGRESS_UNINIT) {
+     _notify_waiters_task.enroll();
+   }
  
    void setup_for_idle();
    void setup_for_mark();
    void setup_for_evac();
    void setup_for_updaterefs();