--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,469 @@
+/*
+ * 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 begining 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;
+};