src/hotspot/share/gc/g1/g1ConcurrentRefine.hpp

rev 47863 : imported patch 8190426-lazy-init-refinement-threads
rev 47864 : [mq]: 8190426-sangheon-review

*** 28,46 ****
  #include "memory/allocation.hpp"
  #include "utilities/globalDefinitions.hpp"
  
  // Forward decl
  class CardTableEntryClosure;
  class G1ConcurrentRefineThread;
  class outputStream;
  class ThreadClosure;
  
! class G1ConcurrentRefine : public CHeapObj<mtGC> {
    G1ConcurrentRefineThread** _threads;
!   uint _n_worker_threads;
   /*
!   * The value of the update buffer queue length falls into one of 3 zones:
    * green, yellow, red. If the value is in [0, green) nothing is
    * done, the buffers are left unprocessed to enable the caching effect of the
    * dirtied cards. In the yellow zone [green, yellow) the concurrent refinement
    * threads are gradually activated. In [yellow, red) all threads are
    * running. If the length becomes red (max queue length) the mutators start
--- 28,79 ----
  #include "memory/allocation.hpp"
  #include "utilities/globalDefinitions.hpp"
  
  // Forward decl
  class CardTableEntryClosure;
+ class G1ConcurrentRefine;
  class G1ConcurrentRefineThread;
  class outputStream;
  class ThreadClosure;
  
! // Helper class for refinement thread management. Used to start, stop and
! // iterate over them.
! class G1ConcurrentRefineThreadControl VALUE_OBJ_CLASS_SPEC {
!   G1ConcurrentRefine* _cr;
! 
    G1ConcurrentRefineThread** _threads;
!   uint _num_max_threads;
! 
!   // Create the refinement thread for the given worker id.
!   // If initializing is true, ignore InjectGCWorkerCreationFailure.
!   G1ConcurrentRefineThread* create_refinement_thread(uint worker_id, bool initializing);
! public:
!   G1ConcurrentRefineThreadControl();
!   ~G1ConcurrentRefineThreadControl();
! 
!   jint initialize(G1ConcurrentRefine* cr, uint num_max_threads);
! 
!   // If there is a "successor" thread that can be activated given the current id,
!   // activate it.
!   void maybe_activate_next(uint cur_worker_id);
! 
!   void print_on(outputStream* st) const;
!   void worker_threads_do(ThreadClosure* tc);
!   void stop();
! };
! 
! // Controls refinement threads and their activation based on the number of completed
! // buffers currently available in the global dirty card queue.
! // Refinement threads pick work from the queue based on these thresholds. They are activated
! // gradually based on the amount of work to do.
! // Refinement thread n activates thread n+1 if the instance of this class determines there
! // is enough work available. Threads deactivate themselves if the current amount of
! // completed buffers falls below their individual threshold.
! class G1ConcurrentRefine : public CHeapObj<mtGC> {
!   G1ConcurrentRefineThreadControl _thread_control;
    /*
!    * The value of the completed dirty card queue length falls into one of 3 zones:
     * green, yellow, red. If the value is in [0, green) nothing is
     * done, the buffers are left unprocessed to enable the caching effect of the
     * dirtied cards. In the yellow zone [green, yellow) the concurrent refinement
     * threads are gradually activated. In [yellow, red) all threads are
     * running. If the length becomes red (max queue length) the mutators start
*** 50,60 ****
    * is turned off):
    * 1) green = yellow = red = 0. In this case the mutator will process all
    *    buffers. Except for those that are created by the deferred updates
    *    machinery during a collection.
    * 2) green = 0. Means no caching. Can be a good way to minimize the
!   *    amount of time spent updating rsets during a collection.
    */
    size_t _green_zone;
    size_t _yellow_zone;
    size_t _red_zone;
    size_t _min_yellow_zone_size;
--- 83,93 ----
     * is turned off):
     * 1) green = yellow = red = 0. In this case the mutator will process all
     *    buffers. Except for those that are created by the deferred updates
     *    machinery during a collection.
     * 2) green = 0. Means no caching. Can be a good way to minimize the
!    *    amount of time spent updating remembered sets during a collection.
     */
    size_t _green_zone;
    size_t _yellow_zone;
    size_t _red_zone;
    size_t _min_yellow_zone_size;
*** 67,94 ****
    // Update green/yellow/red zone values based on how well goals are being met.
    void update_zones(double update_rs_time,
                      size_t update_rs_processed_buffers,
                      double goal_ms);
  
!   // Update thread thresholds to account for updated zone values.
!   void update_thread_thresholds();
  
!  public:
    ~G1ConcurrentRefine();
  
!   // Returns a G1ConcurrentRefine instance if succeeded to create/initialize G1ConcurrentRefine and G1ConcurrentRefineThreads.
!   // Otherwise, returns NULL with error code.
    static G1ConcurrentRefine* create(jint* ecode);
  
    void stop();
  
    void adjust(double update_rs_time, size_t update_rs_processed_buffers, double goal_ms);
  
    // Iterate over all concurrent refinement threads applying the given closure.
    void threads_do(ThreadClosure *tc);
  
!   static uint thread_num();
  
    void print_threads_on(outputStream* st) const;
  
    size_t green_zone() const      { return _green_zone;  }
    size_t yellow_zone() const     { return _yellow_zone; }
--- 100,135 ----
    // Update green/yellow/red zone values based on how well goals are being met.
    void update_zones(double update_rs_time,
                      size_t update_rs_processed_buffers,
                      double goal_ms);
  
!   static uint worker_id_offset();
!   void maybe_activate_more_threads(uint worker_id, size_t num_cur_buffers);
  
!   jint initialize();
! public:
    ~G1ConcurrentRefine();
  
!   // Returns a G1ConcurrentRefine instance if succeeded to create/initialize the
!   // G1ConcurrentRefine instance. Otherwise, returns NULL with error code.
    static G1ConcurrentRefine* create(jint* ecode);
  
    void stop();
  
+   // Adjust refinement thresholds based on work done during the pause and the goal time.
    void adjust(double update_rs_time, size_t update_rs_processed_buffers, double goal_ms);
  
+   size_t activation_threshold(uint worker_id) const;
+   size_t deactivation_threshold(uint worker_id) const;
+   // Perform a single refinement step. Called by the refinement threads when woken up.
+   bool do_refinement_step(uint worker_id);
+ 
    // Iterate over all concurrent refinement threads applying the given closure.
    void threads_do(ThreadClosure *tc);
  
!   // Maximum number of refinement threads.
!   static uint max_num_threads();
  
    void print_threads_on(outputStream* st) const;
  
    size_t green_zone() const      { return _green_zone;  }
    size_t yellow_zone() const     { return _yellow_zone; }