src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp

rev 8068 : 6407976: GC worker number should be unsigned
Reviewed-by: jwilhelm

*** 2904,2915 ****
  
  // The common parts of CMSParInitialMarkTask and CMSParRemarkTask.
  class CMSParMarkTask : public AbstractGangTask {
   protected:
    CMSCollector*     _collector;
!   int               _n_workers;
!   CMSParMarkTask(const char* name, CMSCollector* collector, int n_workers) :
        AbstractGangTask(name),
        _collector(collector),
        _n_workers(n_workers) {}
    // Work method in support of parallel rescan ... of young gen spaces
    void do_young_space_rescan(uint worker_id, OopsInGenClosure* cl,
--- 2904,2915 ----
  
  // The common parts of CMSParInitialMarkTask and CMSParRemarkTask.
  class CMSParMarkTask : public AbstractGangTask {
   protected:
    CMSCollector*     _collector;
!   uint              _n_workers;
!   CMSParMarkTask(const char* name, CMSCollector* collector, uint n_workers) :
        AbstractGangTask(name),
        _collector(collector),
        _n_workers(n_workers) {}
    // Work method in support of parallel rescan ... of young gen spaces
    void do_young_space_rescan(uint worker_id, OopsInGenClosure* cl,
*** 2919,2929 ****
  };
  
  // Parallel initial mark task
  class CMSParInitialMarkTask: public CMSParMarkTask {
   public:
!   CMSParInitialMarkTask(CMSCollector* collector, int n_workers) :
        CMSParMarkTask("Scan roots and young gen for initial mark in parallel",
                       collector, n_workers) {}
    void work(uint worker_id);
  };
  
--- 2919,2929 ----
  };
  
  // Parallel initial mark task
  class CMSParInitialMarkTask: public CMSParMarkTask {
   public:
!   CMSParInitialMarkTask(CMSCollector* collector, uint n_workers) :
        CMSParMarkTask("Scan roots and young gen for initial mark in parallel",
                       collector, n_workers) {}
    void work(uint worker_id);
  };
  
*** 3008,3018 ****
      COMPILER2_PRESENT(DerivedPointerTableDeactivate dpt_deact;)
      if (CMSParallelInitialMarkEnabled && CollectedHeap::use_parallel_gc_threads()) {
        // The parallel version.
        FlexibleWorkGang* workers = gch->workers();
        assert(workers != NULL, "Need parallel worker threads.");
!       int n_workers = workers->active_workers();
        CMSParInitialMarkTask tsk(this, n_workers);
        gch->set_par_threads(n_workers);
        initialize_sequential_subtasks_for_young_gen_rescan(n_workers);
        if (n_workers > 1) {
          StrongRootsScope srs;
--- 3008,3018 ----
      COMPILER2_PRESENT(DerivedPointerTableDeactivate dpt_deact;)
      if (CMSParallelInitialMarkEnabled && CollectedHeap::use_parallel_gc_threads()) {
        // The parallel version.
        FlexibleWorkGang* workers = gch->workers();
        assert(workers != NULL, "Need parallel worker threads.");
!       uint n_workers = workers->active_workers();
        CMSParInitialMarkTask tsk(this, n_workers);
        gch->set_par_threads(n_workers);
        initialize_sequential_subtasks_for_young_gen_rescan(n_workers);
        if (n_workers > 1) {
          StrongRootsScope srs;
*** 3149,3159 ****
  };
  
  // MT Concurrent Marking Task
  class CMSConcMarkingTask: public YieldingFlexibleGangTask {
    CMSCollector* _collector;
!   int           _n_workers;                  // requested/desired # workers
    bool          _result;
    CompactibleFreeListSpace*  _cms_space;
    char          _pad_front[64];   // padding to ...
    HeapWord*     _global_finger;   // ... avoid sharing cache line
    char          _pad_back[64];
--- 3149,3159 ----
  };
  
  // MT Concurrent Marking Task
  class CMSConcMarkingTask: public YieldingFlexibleGangTask {
    CMSCollector* _collector;
!   uint          _n_workers;                  // requested/desired # workers
    bool          _result;
    CompactibleFreeListSpace*  _cms_space;
    char          _pad_front[64];   // padding to ...
    HeapWord*     _global_finger;   // ... avoid sharing cache line
    char          _pad_back[64];
*** 3195,3205 ****
  
    HeapWord** global_finger_addr() { return &_global_finger; }
  
    CMSConcMarkingTerminator* terminator() { return &_term; }
  
!   virtual void set_for_termination(int active_workers) {
      terminator()->reset_for_reuse(active_workers);
    }
  
    void work(uint worker_id);
    bool should_yield() {
--- 3195,3205 ----
  
    HeapWord** global_finger_addr() { return &_global_finger; }
  
    CMSConcMarkingTerminator* terminator() { return &_term; }
  
!   virtual void set_for_termination(uint active_workers) {
      terminator()->reset_for_reuse(active_workers);
    }
  
    void work(uint worker_id);
    bool should_yield() {
*** 3641,3651 ****
    _collector->startTimer();
  }
  
  bool CMSCollector::do_marking_mt() {
    assert(ConcGCThreads > 0 && conc_workers() != NULL, "precondition");
!   int num_workers = AdaptiveSizePolicy::calc_active_conc_workers(
                                         conc_workers()->total_workers(),
                                         conc_workers()->active_workers(),
                                         Threads::number_of_non_daemon_threads());
    conc_workers()->set_active_workers(num_workers);
  
--- 3641,3651 ----
    _collector->startTimer();
  }
  
  bool CMSCollector::do_marking_mt() {
    assert(ConcGCThreads > 0 && conc_workers() != NULL, "precondition");
!   uint num_workers = AdaptiveSizePolicy::calc_active_conc_workers(
                                         conc_workers()->total_workers(),
                                         conc_workers()->active_workers(),
                                         Threads::number_of_non_daemon_threads());
    conc_workers()->set_active_workers(num_workers);
  
*** 4490,4500 ****
   public:
    // A value of 0 passed to n_workers will cause the number of
    // workers to be taken from the active workers in the work gang.
    CMSParRemarkTask(CMSCollector* collector,
                     CompactibleFreeListSpace* cms_space,
!                    int n_workers, FlexibleWorkGang* workers,
                     OopTaskQueueSet* task_queues):
      CMSParMarkTask("Rescan roots and grey objects in parallel",
                     collector, n_workers),
      _cms_space(cms_space),
      _task_queues(task_queues),
--- 4490,4500 ----
   public:
    // A value of 0 passed to n_workers will cause the number of
    // workers to be taken from the active workers in the work gang.
    CMSParRemarkTask(CMSCollector* collector,
                     CompactibleFreeListSpace* cms_space,
!                    uint n_workers, FlexibleWorkGang* workers,
                     OopTaskQueueSet* task_queues):
      CMSParMarkTask("Rescan roots and grey objects in parallel",
                     collector, n_workers),
      _cms_space(cms_space),
      _task_queues(task_queues),
*** 4503,4513 ****
    OopTaskQueueSet* task_queues() { return _task_queues; }
  
    OopTaskQueue* work_queue(int i) { return task_queues()->queue(i); }
  
    ParallelTaskTerminator* terminator() { return &_term; }
!   int n_workers() { return _n_workers; }
  
    void work(uint worker_id);
  
   private:
    // ... of  dirty cards in old space
--- 4503,4513 ----
    OopTaskQueueSet* task_queues() { return _task_queues; }
  
    OopTaskQueue* work_queue(int i) { return task_queues()->queue(i); }
  
    ParallelTaskTerminator* terminator() { return &_term; }
!   uint n_workers() { return _n_workers; }
  
    void work(uint worker_id);
  
   private:
    // ... of  dirty cards in old space
*** 5066,5076 ****
    FlexibleWorkGang* workers = gch->workers();
    assert(workers != NULL, "Need parallel worker threads.");
    // Choose to use the number of GC workers most recently set
    // into "active_workers".  If active_workers is not set, set it
    // to ParallelGCThreads.
!   int n_workers = workers->active_workers();
    if (n_workers == 0) {
      assert(n_workers > 0, "Should have been set during scavenge");
      n_workers = ParallelGCThreads;
      workers->set_active_workers(n_workers);
    }
--- 5066,5076 ----
    FlexibleWorkGang* workers = gch->workers();
    assert(workers != NULL, "Need parallel worker threads.");
    // Choose to use the number of GC workers most recently set
    // into "active_workers".  If active_workers is not set, set it
    // to ParallelGCThreads.
!   uint n_workers = workers->active_workers();
    if (n_workers == 0) {
      assert(n_workers > 0, "Should have been set during scavenge");
      n_workers = ParallelGCThreads;
      workers->set_active_workers(n_workers);
    }
*** 5432,5442 ****
        // may have been a different number of threads doing the discovery
        // and a different number of discovered lists may have Ref objects.
        // That is OK as long as the Reference lists are balanced (see
        // balance_all_queues() and balance_queues()).
        GenCollectedHeap* gch = GenCollectedHeap::heap();
!       int active_workers = ParallelGCThreads;
        FlexibleWorkGang* workers = gch->workers();
        if (workers != NULL) {
          active_workers = workers->active_workers();
          // The expectation is that active_workers will have already
          // been set to a reasonable value.  If it has not been set,
--- 5432,5442 ----
        // may have been a different number of threads doing the discovery
        // and a different number of discovered lists may have Ref objects.
        // That is OK as long as the Reference lists are balanced (see
        // balance_all_queues() and balance_queues()).
        GenCollectedHeap* gch = GenCollectedHeap::heap();
!       uint active_workers = ParallelGCThreads;
        FlexibleWorkGang* workers = gch->workers();
        if (workers != NULL) {
          active_workers = workers->active_workers();
          // The expectation is that active_workers will have already
          // been set to a reasonable value.  If it has not been set,