jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp@98cb887364d3 (annotated)

src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp@98cb887364d3 (annotated)

src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp

Fri, 27 Feb 2009 13:27:09 -0800

author: twisti
date: Fri, 27 Feb 2009 13:27:09 -0800
changeset 1040: 98cb887364d3
parent 435: a61af66fc99e
child 1907: c18cbe5936b8
permissions: -rw-r--r--

6810672: Comment typos
Summary: I have collected some typos I have found while looking at the code.
Reviewed-by: kvn, never

 /*
  * Copyright 2004-2006 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 // This class keeps statistical information and computes the
 // size of the heap for the concurrent mark sweep collector.
 //
 // Cost for garbage collector include cost for
 //   minor collection
 //   concurrent collection
 //      stop-the-world component
 //      concurrent component
 //   major compacting collection
 //      uses decaying cost
 // Forward decls
 class elapsedTimer;
 class CMSAdaptiveSizePolicy : public AdaptiveSizePolicy {
  friend class CMSGCAdaptivePolicyCounters;
  friend class CMSCollector;
  private:
   // Total number of processors available
   int _processor_count;
   // Number of processors used by the concurrent phases of GC
   // This number is assumed to be the same for all concurrent
   // phases.
   int _concurrent_processor_count;
   // Time that the mutators run exclusive of a particular
   // phase.  For example, the time the mutators run excluding
   // the time during which the cms collector runs concurrently
   // with the mutators.
   //   Between end of most recent cms reset and start of initial mark
                 // This may be redundant
   double _latest_cms_reset_end_to_initial_mark_start_secs;
   //   Between end of the most recent initial mark and start of remark
   double _latest_cms_initial_mark_end_to_remark_start_secs;
   //   Between end of most recent collection and start of
   //   a concurrent collection
   double _latest_cms_collection_end_to_collection_start_secs;
   //   Times of the concurrent phases of the most recent
   //   concurrent collection
   double _latest_cms_concurrent_marking_time_secs;
   double _latest_cms_concurrent_precleaning_time_secs;
   double _latest_cms_concurrent_sweeping_time_secs;
   //   Between end of most recent STW MSC and start of next STW MSC
   double _latest_cms_msc_end_to_msc_start_time_secs;
   //   Between end of most recent MS and start of next MS
   //   This does not include any time spent during a concurrent
   // collection.
   double _latest_cms_ms_end_to_ms_start;
   //   Between start and end of the initial mark of the most recent
   // concurrent collection.
   double _latest_cms_initial_mark_start_to_end_time_secs;
   //   Between start and end of the remark phase of the most recent
   // concurrent collection
   double _latest_cms_remark_start_to_end_time_secs;
   //   Between start and end of the most recent MS STW marking phase
   double _latest_cms_ms_marking_start_to_end_time_secs;
   // Pause time timers
   static elapsedTimer _STW_timer;
   // Concurrent collection timer.  Used for total of all concurrent phases
   // during 1 collection cycle.
   static elapsedTimer _concurrent_timer;
   // When the size of the generation is changed, the size
   // of the change will rounded up or down (depending on the
   // type of change) by this value.
   size_t _generation_alignment;
   // If this variable is true, the size of the young generation
   // may be changed in order to reduce the pause(s) of the
   // collection of the tenured generation in order to meet the
   // pause time goal.  It is common to change the size of the
   // tenured generation in order to meet the pause time goal
   // for the tenured generation.  With the CMS collector for
   // the tenured generation, the size of the young generation
   // can have an significant affect on the pause times for collecting the
   // tenured generation.
   // This is a duplicate of a variable in PSAdaptiveSizePolicy.  It
   // is duplicated because it is not clear that it is general enough
   // to go into AdaptiveSizePolicy.
   int _change_young_gen_for_maj_pauses;
   // Variable that is set to true after a collection.
   bool _first_after_collection;
   // Fraction of collections that are of each type
   double concurrent_fraction() const;
   double STW_msc_fraction() const;
   double STW_ms_fraction() const;
   // This call cannot be put into the epilogue as long as some
   // of the counters can be set during concurrent phases.
   virtual void clear_generation_free_space_flags();
   void set_first_after_collection() { _first_after_collection = true; }
  protected:
   // Average of the sum of the concurrent times for
   // one collection in seconds.
   AdaptiveWeightedAverage* _avg_concurrent_time;
   // Average time between concurrent collections in seconds.
   AdaptiveWeightedAverage* _avg_concurrent_interval;
   // Average cost of the concurrent part of a collection
   // in seconds.
   AdaptiveWeightedAverage* _avg_concurrent_gc_cost;
   // Average of the initial pause of a concurrent collection in seconds.
   AdaptivePaddedAverage* _avg_initial_pause;
   // Average of the remark pause of a concurrent collection in seconds.
   AdaptivePaddedAverage* _avg_remark_pause;
   // Average of the stop-the-world (STW) (initial mark + remark)
   // times in seconds for concurrent collections.
   AdaptiveWeightedAverage* _avg_cms_STW_time;
   // Average of the STW collection cost for concurrent collections.
   AdaptiveWeightedAverage* _avg_cms_STW_gc_cost;
   // Average of the bytes free at the start of the sweep.
   AdaptiveWeightedAverage* _avg_cms_free_at_sweep;
   // Average of the bytes free at the end of the collection.
   AdaptiveWeightedAverage* _avg_cms_free;
   // Average of the bytes promoted between cms collections.
   AdaptiveWeightedAverage* _avg_cms_promo;
   // stop-the-world (STW) mark-sweep-compact
   // Average of the pause time in seconds for STW mark-sweep-compact
   // collections.
   AdaptiveWeightedAverage* _avg_msc_pause;
   // Average of the interval in seconds between STW mark-sweep-compact
   // collections.
   AdaptiveWeightedAverage* _avg_msc_interval;
   // Average of the collection costs for STW mark-sweep-compact
   // collections.
   AdaptiveWeightedAverage* _avg_msc_gc_cost;
   // Averages for mark-sweep collections.
   // The collection may have started as a background collection
   // that completes in a stop-the-world (STW) collection.
   // Average of the pause time in seconds for mark-sweep
   // collections.
   AdaptiveWeightedAverage* _avg_ms_pause;
   // Average of the interval in seconds between mark-sweep
   // collections.
   AdaptiveWeightedAverage* _avg_ms_interval;
   // Average of the collection costs for mark-sweep
   // collections.
   AdaptiveWeightedAverage* _avg_ms_gc_cost;
   // These variables contain a linear fit of
   // a generation size as the independent variable
   // and a pause time as the dependent variable.
   // For example _remark_pause_old_estimator
   // is a fit of the old generation size as the
   // independent variable and the remark pause
   // as the dependent variable.
   //   remark pause time vs. cms gen size
   LinearLeastSquareFit* _remark_pause_old_estimator;
   //   initial pause time vs. cms gen size
   LinearLeastSquareFit* _initial_pause_old_estimator;
   //   remark pause time vs. young gen size
   LinearLeastSquareFit* _remark_pause_young_estimator;
   //   initial pause time vs. young gen size
   LinearLeastSquareFit* _initial_pause_young_estimator;
   // Accessors
   int processor_count() const { return _processor_count; }
   int concurrent_processor_count() const { return _concurrent_processor_count; }
   AdaptiveWeightedAverage* avg_concurrent_time() const {
     return _avg_concurrent_time;
   }
   AdaptiveWeightedAverage* avg_concurrent_interval() const {
     return _avg_concurrent_interval;
   }
   AdaptiveWeightedAverage* avg_concurrent_gc_cost() const {
     return _avg_concurrent_gc_cost;
   }
   AdaptiveWeightedAverage* avg_cms_STW_time() const {
     return _avg_cms_STW_time;
   }
   AdaptiveWeightedAverage* avg_cms_STW_gc_cost() const {
     return _avg_cms_STW_gc_cost;
   }
   AdaptivePaddedAverage* avg_initial_pause() const {
     return _avg_initial_pause;
   }
   AdaptivePaddedAverage* avg_remark_pause() const {
     return _avg_remark_pause;
   }
   AdaptiveWeightedAverage* avg_cms_free() const {
     return _avg_cms_free;
   }
   AdaptiveWeightedAverage* avg_cms_free_at_sweep() const {
     return _avg_cms_free_at_sweep;
   }
   AdaptiveWeightedAverage* avg_msc_pause() const {
     return _avg_msc_pause;
   }
   AdaptiveWeightedAverage* avg_msc_interval() const {
     return _avg_msc_interval;
   }
   AdaptiveWeightedAverage* avg_msc_gc_cost() const {
     return _avg_msc_gc_cost;
   }
   AdaptiveWeightedAverage* avg_ms_pause() const {
     return _avg_ms_pause;
   }
   AdaptiveWeightedAverage* avg_ms_interval() const {
     return _avg_ms_interval;
   }
   AdaptiveWeightedAverage* avg_ms_gc_cost() const {
     return _avg_ms_gc_cost;
   }
   LinearLeastSquareFit* remark_pause_old_estimator() {
     return _remark_pause_old_estimator;
   }
   LinearLeastSquareFit* initial_pause_old_estimator() {
     return _initial_pause_old_estimator;
   }
   LinearLeastSquareFit* remark_pause_young_estimator() {
     return _remark_pause_young_estimator;
   }
   LinearLeastSquareFit* initial_pause_young_estimator() {
     return _initial_pause_young_estimator;
   }
   // These *slope() methods return the slope
   // m for the linear fit of an independent
   // variable vs. a dependent variable.  For
   // example
   //  remark_pause = m * old_generation_size + c
   // These may be used to determine if an
   // adjustment should be made to achieve a goal.
   // For example, if remark_pause_old_slope() is
   // positive, a reduction of the old generation
   // size has on average resulted in the reduction
   // of the remark pause.
   float remark_pause_old_slope() {
     return _remark_pause_old_estimator->slope();
   }
   float initial_pause_old_slope() {
     return _initial_pause_old_estimator->slope();
   }
   float remark_pause_young_slope() {
     return _remark_pause_young_estimator->slope();
   }
   float initial_pause_young_slope() {
     return _initial_pause_young_estimator->slope();
   }
   // Update estimators
   void update_minor_pause_old_estimator(double minor_pause_in_ms);
   // Fraction of processors used by the concurrent phases.
   double concurrent_processor_fraction();
   // Returns the total times for the concurrent part of the
   // latest collection in seconds.
   double concurrent_collection_time();
   // Return the total times for the concurrent part of the
   // latest collection in seconds where the times of the various
   // concurrent phases are scaled by the processor fraction used
   // during the phase.
   double scaled_concurrent_collection_time();
   // Dimensionless concurrent GC cost for all the concurrent phases.
   double concurrent_collection_cost(double interval_in_seconds);
   // Dimensionless GC cost
   double collection_cost(double pause_in_seconds, double interval_in_seconds);
   virtual GCPolicyKind kind() const { return _gc_cms_adaptive_size_policy; }
   virtual double time_since_major_gc() const;
   // This returns the maximum average for the concurrent, ms, and
   // msc collections.  This is meant to be used for the calculation
   // of the decayed major gc cost and is not in general the
   // average of all the different types of major collections.
   virtual double major_gc_interval_average_for_decay() const;
  public:
   CMSAdaptiveSizePolicy(size_t init_eden_size,
                         size_t init_promo_size,
                         size_t init_survivor_size,
                         double max_gc_minor_pause_sec,
                         double max_gc_pause_sec,
                         uint gc_cost_ratio);
   // The timers for the stop-the-world phases measure a total
   // stop-the-world time.  The timer is started and stopped
   // for each phase but is only reset after the final checkpoint.
   void checkpoint_roots_initial_begin();
   void checkpoint_roots_initial_end(GCCause::Cause gc_cause);
   void checkpoint_roots_final_begin();
   void checkpoint_roots_final_end(GCCause::Cause gc_cause);
   // Methods for gathering information about the
   // concurrent marking phase of the collection.
   // Records the mutator times and
   // resets the concurrent timer.
   void concurrent_marking_begin();
   // Resets concurrent phase timer in the begin methods and
   // saves the time for a phase in the end methods.
   void concurrent_marking_end();
   void concurrent_sweeping_begin();
   void concurrent_sweeping_end();
   // Similar to the above (e.g., concurrent_marking_end()) and
   // is used for both the precleaning an abortable precleaing
   // phases.
   void concurrent_precleaning_begin();
   void concurrent_precleaning_end();
   // Stops the concurrent phases time.  Gathers
   // information and resets the timer.
   void concurrent_phases_end(GCCause::Cause gc_cause,
                               size_t cur_eden,
                               size_t cur_promo);
   // Methods for gather information about STW Mark-Sweep-Compact
   void msc_collection_begin();
   void msc_collection_end(GCCause::Cause gc_cause);
   // Methods for gather information about Mark-Sweep done
   // in the foreground.
   void ms_collection_begin();
   void ms_collection_end(GCCause::Cause gc_cause);
   // Cost for a mark-sweep tenured gen collection done in the foreground
   double ms_gc_cost() const {
     return MAX2(0.0F, _avg_ms_gc_cost->average());
   }
   // Cost of collecting the tenured generation.  Includes
   // concurrent collection and STW collection costs
   double cms_gc_cost() const;
   // Cost of STW mark-sweep-compact tenured gen collection.
   double msc_gc_cost() const {
     return MAX2(0.0F, _avg_msc_gc_cost->average());
   }
   //
   double compacting_gc_cost() const {
     double result = MIN2(1.0, minor_gc_cost() + msc_gc_cost());
     assert(result >= 0.0, "Both minor and major costs are non-negative");
     return result;
   }
    // Restarts the concurrent phases timer.
    void concurrent_phases_resume();
    // Time beginning and end of the marking phase for
    // a synchronous MS collection.  A MS collection
    // that finishes in the foreground can have started
    // in the background.  These methods capture the
    // completion of the marking (after the initial
    // marking) that is done in the foreground.
    void ms_collection_marking_begin();
    void ms_collection_marking_end(GCCause::Cause gc_cause);
    static elapsedTimer* concurrent_timer_ptr() {
      return &_concurrent_timer;
    }
   AdaptiveWeightedAverage* avg_cms_promo() const {
     return _avg_cms_promo;
   }
   int change_young_gen_for_maj_pauses() {
     return _change_young_gen_for_maj_pauses;
   }
   void set_change_young_gen_for_maj_pauses(int v) {
     _change_young_gen_for_maj_pauses = v;
   }
   void clear_internal_time_intervals();
   // Either calculated_promo_size_in_bytes() or promo_size()
   // should be deleted.
   size_t promo_size() { return _promo_size; }
   void set_promo_size(size_t v) { _promo_size = v; }
   // Cost of GC for all types of collections.
   virtual double gc_cost() const;
   size_t generation_alignment() { return _generation_alignment; }
   virtual void compute_young_generation_free_space(size_t cur_eden,
                                                    size_t max_eden_size);
   // Calculates new survivor space size;  returns a new tenuring threshold
   // value. Stores new survivor size in _survivor_size.
   virtual int compute_survivor_space_size_and_threshold(
                                                 bool   is_survivor_overflow,
                                                 int    tenuring_threshold,
                                                 size_t survivor_limit);
   virtual void compute_tenured_generation_free_space(size_t cur_tenured_free,
                                            size_t max_tenured_available,
                                            size_t cur_eden);
   size_t eden_decrement_aligned_down(size_t cur_eden);
   size_t eden_increment_aligned_up(size_t cur_eden);
   size_t adjust_eden_for_pause_time(size_t cur_eden);
   size_t adjust_eden_for_throughput(size_t cur_eden);
   size_t adjust_eden_for_footprint(size_t cur_eden);
   size_t promo_decrement_aligned_down(size_t cur_promo);
   size_t promo_increment_aligned_up(size_t cur_promo);
   size_t adjust_promo_for_pause_time(size_t cur_promo);
   size_t adjust_promo_for_throughput(size_t cur_promo);
   size_t adjust_promo_for_footprint(size_t cur_promo, size_t cur_eden);
   // Scale down the input size by the ratio of the cost to collect the
   // generation to the total GC cost.
   size_t scale_by_gen_gc_cost(size_t base_change, double gen_gc_cost);
   // Return the value and clear it.
   bool get_and_clear_first_after_collection();
   // Printing support
   virtual bool print_adaptive_size_policy_on(outputStream* st) const;
 };

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp@98cb887364d3 (annotated)

src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp