src/share/vm/gc_implementation/shared/allocationStats.hpp - platform/external/jetbrains/jdk8u_hotspot - Git at Google

 /*
  * Copyright (c) 2001, 2014, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */

 #ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP

 #include "utilities/macros.hpp"
 #include "memory/allocation.hpp"
 #include "utilities/globalDefinitions.hpp"
 #include "gc_implementation/shared/gcUtil.hpp"

 class AllocationStats VALUE_OBJ_CLASS_SPEC {
   // A duration threshold (in ms) used to filter
   // possibly unreliable samples.
   static float _threshold;

   // We measure the demand between the end of the previous sweep and
   // beginning of this sweep:
   //   Count(end_last_sweep) - Count(start_this_sweep)
   //     + split_births(between) - split_deaths(between)
   // The above number divided by the time since the end of the
   // previous sweep gives us a time rate of demand for blocks
   // of this size. We compute a padded average of this rate as
   // our current estimate for the time rate of demand for blocks
   // of this size. Similarly, we keep a padded average for the time
   // between sweeps. Our current estimate for demand for blocks of
   // this size is then simply computed as the product of these two
   // estimates.
   AdaptivePaddedAverage _demand_rate_estimate;

   ssize_t     _desired;         // Demand stimate computed as described above
   ssize_t     _coal_desired;     // desired +/- small-percent for tuning coalescing

   ssize_t     _surplus;         // count - (desired +/- small-percent),
                                 // used to tune splitting in best fit
   ssize_t     _bfr_surp;         // surplus at start of current sweep
   ssize_t     _prev_sweep;       // count from end of previous sweep
   ssize_t     _before_sweep;     // count from before current sweep
   ssize_t     _coal_births;      // additional chunks from coalescing
   ssize_t     _coal_deaths;      // loss from coalescing
   ssize_t     _split_births;     // additional chunks from splitting
   ssize_t     _split_deaths;     // loss from splitting
   size_t      _returned_bytes;   // number of bytes returned to list.
  public:
   void initialize(bool split_birth = false) {
     AdaptivePaddedAverage* dummy =
       new (&_demand_rate_estimate) AdaptivePaddedAverage(CMS_FLSWeight,
                                                          CMS_FLSPadding);
     _desired = 0;
     _coal_desired = 0;
     _surplus = 0;
     _bfr_surp = 0;
     _prev_sweep = 0;
     _before_sweep = 0;
     _coal_births = 0;
     _coal_deaths = 0;
     _split_births = (split_birth ? 1 : 0);
     _split_deaths = 0;
     _returned_bytes = 0;
   }

   AllocationStats() {
     initialize();
   }

   // The rate estimate is in blocks per second.
   void compute_desired(size_t count,
                        float inter_sweep_current,
                        float inter_sweep_estimate,
                        float intra_sweep_estimate) {
     // If the latest inter-sweep time is below our granularity
     // of measurement, we may call in here with
     // inter_sweep_current == 0. However, even for suitably small
     // but non-zero inter-sweep durations, we may not trust the accuracy
     // of accumulated data, since it has not been "integrated"
     // (read "low-pass-filtered") long enough, and would be
     // vulnerable to noisy glitches. In such cases, we
     // ignore the current sample and use currently available
     // historical estimates.
     assert(prev_sweep() + split_births() + coal_births()        // "Total Production Stock"
            >= split_deaths() + coal_deaths() + (ssize_t)count, // "Current stock + depletion"
            "Conservation Principle");
     if (inter_sweep_current > _threshold) {
       ssize_t demand = prev_sweep() - (ssize_t)count + split_births() + coal_births()
                        - split_deaths() - coal_deaths();
       assert(demand >= 0,
              err_msg("Demand (" SSIZE_FORMAT ") should be non-negative for "
                      PTR_FORMAT " (size=" SIZE_FORMAT ")",
                      demand, p2i(this), count));
       // Defensive: adjust for imprecision in event counting
       if (demand < 0) {
         demand = 0;
       }
       float old_rate = _demand_rate_estimate.padded_average();
       float rate = ((float)demand)/inter_sweep_current;
       _demand_rate_estimate.sample(rate);
       float new_rate = _demand_rate_estimate.padded_average();
       ssize_t old_desired = _desired;
       float delta_ise = (CMSExtrapolateSweep ? intra_sweep_estimate : 0.0);
       _desired = (ssize_t)(new_rate * (inter_sweep_estimate + delta_ise));
       if (PrintFLSStatistics > 1) {
         gclog_or_tty->print_cr(
         "demand: " SSIZE_FORMAT ", old_rate: %f, current_rate: %f, new_rate: %f, old_desired: " SSIZE_FORMAT ", new_desired: " SSIZE_FORMAT,
                            demand,     old_rate,             rate,     new_rate,                 old_desired,                   _desired);
       }
     }
   }

   ssize_t desired() const { return _desired; }
   void set_desired(ssize_t v) { _desired = v; }

   ssize_t coal_desired() const { return _coal_desired; }
   void set_coal_desired(ssize_t v) { _coal_desired = v; }

   ssize_t surplus() const { return _surplus; }
   void set_surplus(ssize_t v) { _surplus = v; }
   void increment_surplus() { _surplus++; }
   void decrement_surplus() { _surplus--; }

   ssize_t bfr_surp() const { return _bfr_surp; }
   void set_bfr_surp(ssize_t v) { _bfr_surp = v; }
   ssize_t prev_sweep() const { return _prev_sweep; }
   void set_prev_sweep(ssize_t v) { _prev_sweep = v; }
   ssize_t before_sweep() const { return _before_sweep; }
   void set_before_sweep(ssize_t v) { _before_sweep = v; }

   ssize_t coal_births() const { return _coal_births; }
   void set_coal_births(ssize_t v) { _coal_births = v; }
   void increment_coal_births() { _coal_births++; }

   ssize_t coal_deaths() const { return _coal_deaths; }
   void set_coal_deaths(ssize_t v) { _coal_deaths = v; }
   void increment_coal_deaths() { _coal_deaths++; }

   ssize_t split_births() const { return _split_births; }
   void set_split_births(ssize_t v) { _split_births = v; }
   void increment_split_births() { _split_births++; }

   ssize_t split_deaths() const { return _split_deaths; }
   void set_split_deaths(ssize_t v) { _split_deaths = v; }
   void increment_split_deaths() { _split_deaths++; }

   NOT_PRODUCT(
     size_t returned_bytes() const { return _returned_bytes; }
     void set_returned_bytes(size_t v) { _returned_bytes = v; }
   )
 };

 #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP
	/*
	* Copyright (c) 2001, 2014, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*
	*/

	#ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP
	#define SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP

	#include "utilities/macros.hpp"
	#include "memory/allocation.hpp"
	#include "utilities/globalDefinitions.hpp"
	#include "gc_implementation/shared/gcUtil.hpp"

	class AllocationStats VALUE_OBJ_CLASS_SPEC {
	// A duration threshold (in ms) used to filter
	// possibly unreliable samples.
	static float _threshold;

	// We measure the demand between the end of the previous sweep and
	// beginning of this sweep:
	// Count(end_last_sweep) - Count(start_this_sweep)
	// + split_births(between) - split_deaths(between)
	// The above number divided by the time since the end of the
	// previous sweep gives us a time rate of demand for blocks
	// of this size. We compute a padded average of this rate as
	// our current estimate for the time rate of demand for blocks
	// of this size. Similarly, we keep a padded average for the time
	// between sweeps. Our current estimate for demand for blocks of
	// this size is then simply computed as the product of these two
	// estimates.
	AdaptivePaddedAverage _demand_rate_estimate;

	ssize_t _desired; // Demand stimate computed as described above
	ssize_t _coal_desired; // desired +/- small-percent for tuning coalescing

	ssize_t _surplus; // count - (desired +/- small-percent),
	// used to tune splitting in best fit
	ssize_t _bfr_surp; // surplus at start of current sweep
	ssize_t _prev_sweep; // count from end of previous sweep
	ssize_t _before_sweep; // count from before current sweep
	ssize_t _coal_births; // additional chunks from coalescing
	ssize_t _coal_deaths; // loss from coalescing
	ssize_t _split_births; // additional chunks from splitting
	ssize_t _split_deaths; // loss from splitting
	size_t _returned_bytes; // number of bytes returned to list.
	public:
	void initialize(bool split_birth = false) {
	AdaptivePaddedAverage* dummy =
	new (&_demand_rate_estimate) AdaptivePaddedAverage(CMS_FLSWeight,
	CMS_FLSPadding);
	_desired = 0;
	_coal_desired = 0;
	_surplus = 0;
	_bfr_surp = 0;
	_prev_sweep = 0;
	_before_sweep = 0;
	_coal_births = 0;
	_coal_deaths = 0;
	_split_births = (split_birth ? 1 : 0);
	_split_deaths = 0;
	_returned_bytes = 0;
	}

	AllocationStats() {
	initialize();
	}

	// The rate estimate is in blocks per second.
	void compute_desired(size_t count,
	float inter_sweep_current,
	float inter_sweep_estimate,
	float intra_sweep_estimate) {
	// If the latest inter-sweep time is below our granularity
	// of measurement, we may call in here with
	// inter_sweep_current == 0. However, even for suitably small
	// but non-zero inter-sweep durations, we may not trust the accuracy
	// of accumulated data, since it has not been "integrated"
	// (read "low-pass-filtered") long enough, and would be
	// vulnerable to noisy glitches. In such cases, we
	// ignore the current sample and use currently available
	// historical estimates.
	assert(prev_sweep() + split_births() + coal_births() // "Total Production Stock"
	>= split_deaths() + coal_deaths() + (ssize_t)count, // "Current stock + depletion"
	"Conservation Principle");
	if (inter_sweep_current > _threshold) {
	ssize_t demand = prev_sweep() - (ssize_t)count + split_births() + coal_births()
	- split_deaths() - coal_deaths();
	assert(demand >= 0,
	err_msg("Demand (" SSIZE_FORMAT ") should be non-negative for "
	PTR_FORMAT " (size=" SIZE_FORMAT ")",
	demand, p2i(this), count));
	// Defensive: adjust for imprecision in event counting
	if (demand < 0) {
	demand = 0;
	}
	float old_rate = _demand_rate_estimate.padded_average();
	float rate = ((float)demand)/inter_sweep_current;
	_demand_rate_estimate.sample(rate);
	float new_rate = _demand_rate_estimate.padded_average();
	ssize_t old_desired = _desired;
	float delta_ise = (CMSExtrapolateSweep ? intra_sweep_estimate : 0.0);
	_desired = (ssize_t)(new_rate * (inter_sweep_estimate + delta_ise));
	if (PrintFLSStatistics > 1) {
	gclog_or_tty->print_cr(
	"demand: " SSIZE_FORMAT ", old_rate: %f, current_rate: %f, new_rate: %f, old_desired: " SSIZE_FORMAT ", new_desired: " SSIZE_FORMAT,
	demand, old_rate, rate, new_rate, old_desired, _desired);
	}
	}
	}

	ssize_t desired() const { return _desired; }
	void set_desired(ssize_t v) { _desired = v; }

	ssize_t coal_desired() const { return _coal_desired; }
	void set_coal_desired(ssize_t v) { _coal_desired = v; }

	ssize_t surplus() const { return _surplus; }
	void set_surplus(ssize_t v) { _surplus = v; }
	void increment_surplus() { _surplus++; }
	void decrement_surplus() { _surplus--; }

	ssize_t bfr_surp() const { return _bfr_surp; }
	void set_bfr_surp(ssize_t v) { _bfr_surp = v; }
	ssize_t prev_sweep() const { return _prev_sweep; }
	void set_prev_sweep(ssize_t v) { _prev_sweep = v; }
	ssize_t before_sweep() const { return _before_sweep; }
	void set_before_sweep(ssize_t v) { _before_sweep = v; }

	ssize_t coal_births() const { return _coal_births; }
	void set_coal_births(ssize_t v) { _coal_births = v; }
	void increment_coal_births() { _coal_births++; }

	ssize_t coal_deaths() const { return _coal_deaths; }
	void set_coal_deaths(ssize_t v) { _coal_deaths = v; }
	void increment_coal_deaths() { _coal_deaths++; }

	ssize_t split_births() const { return _split_births; }
	void set_split_births(ssize_t v) { _split_births = v; }
	void increment_split_births() { _split_births++; }

	ssize_t split_deaths() const { return _split_deaths; }
	void set_split_deaths(ssize_t v) { _split_deaths = v; }
	void increment_split_deaths() { _split_deaths++; }

	NOT_PRODUCT(
	size_t returned_bytes() const { return _returned_bytes; }
	void set_returned_bytes(size_t v) { _returned_bytes = v; }
	)
	};

	#endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_ALLOCATIONSTATS_HPP