jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1MMUTracker.cpp@b9bc732be7c0 (annotated)

src/share/vm/gc_implementation/g1/g1MMUTracker.cpp@b9bc732be7c0 (annotated)

src/share/vm/gc_implementation/g1/g1MMUTracker.cpp

Thu, 10 Jun 2010 08:27:35 -0700

author: jmasa
date: Thu, 10 Jun 2010 08:27:35 -0700
changeset 1949: b9bc732be7c0
parent 1907: c18cbe5936b8
parent 1946: f16f1d7893de
child 2314: f95d63e2154a
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 2001, 2009, 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.
  *
  */
 #include "incls/_precompiled.incl"
 #include "incls/_g1MMUTracker.cpp.incl"
 #define _DISABLE_MMU                             0
 // can't rely on comparing doubles with tolerating a small margin for error
 #define SMALL_MARGIN 0.0000001
 #define is_double_leq_0(_value) ( (_value) < SMALL_MARGIN )
 #define is_double_leq(_val1, _val2) is_double_leq_0((_val1) - (_val2))
 #define is_double_geq(_val1, _val2) is_double_leq_0((_val2) - (_val1))
 /***** ALL TIMES ARE IN SECS!!!!!!! *****/
 G1MMUTracker::G1MMUTracker(double time_slice, double max_gc_time) :
   _time_slice(time_slice),
   _max_gc_time(max_gc_time) { }
 G1MMUTrackerQueue::G1MMUTrackerQueue(double time_slice, double max_gc_time) :
   G1MMUTracker(time_slice, max_gc_time),
   _head_index(0),
   _tail_index(trim_index(_head_index+1)),
   _no_entries(0) { }
 void G1MMUTrackerQueue::remove_expired_entries(double current_time) {
   double limit = current_time - _time_slice;
   while (_no_entries > 0) {
     if (is_double_geq(limit, _array[_tail_index].end_time())) {
       _tail_index = trim_index(_tail_index + 1);
       --_no_entries;
     } else
       return;
   }
   guarantee(_no_entries == 0, "should have no entries in the array");
 }
 double G1MMUTrackerQueue::calculate_gc_time(double current_time) {
   double gc_time = 0.0;
   double limit = current_time - _time_slice;
   for (int i = 0; i < _no_entries; ++i) {
     int index = trim_index(_tail_index + i);
     G1MMUTrackerQueueElem *elem = &_array[index];
     if (elem->end_time() > limit) {
       if (elem->start_time() > limit)
         gc_time += elem->duration();
       else
         gc_time += elem->end_time() - limit;
     }
   }
   return gc_time;
 }
 void G1MMUTrackerQueue::add_pause(double start, double end, bool gc_thread) {
   double longest_allowed = longest_pause_internal(start);
   if (longest_allowed < 0.0)
     longest_allowed = 0.0;
   double duration = end - start;
   remove_expired_entries(end);
   if (_no_entries == QueueLength) {
     // OK, we've filled up the queue. There are a few ways
     // of dealing with this "gracefully"
     //   increase the array size (:-)
     //   remove the oldest entry (this might allow more GC time for
     //     the time slice than what's allowed) - this is what we
     //     currently do
     //   consolidate the two entries with the minimum gap between them
     //     (this might allow less GC time than what's allowed)
     // In the case where ScavengeALot is true, such overflow is not
     // uncommon; in such cases, we can, without much loss of precision
     // or performance (we are GC'ing most of the time anyway!),
     // simply overwrite the oldest entry in the tracker.
     if (G1PolicyVerbose > 1) {
       warning("MMU Tracker Queue overflow. Replacing earliest entry.");
     }
     _head_index = trim_index(_head_index + 1);
     assert(_head_index == _tail_index, "Because we have a full circular buffer");
     _tail_index = trim_index(_tail_index + 1);
   } else {
     _head_index = trim_index(_head_index + 1);
     ++_no_entries;
   }
   _array[_head_index] = G1MMUTrackerQueueElem(start, end);
 }
 // basically the _internal call does not remove expired entries
 // this is for trying things out in the future and a couple
 // of other places (debugging)
 double G1MMUTrackerQueue::longest_pause(double current_time) {
   if (_DISABLE_MMU)
     return _max_gc_time;
   MutexLockerEx x(MMUTracker_lock, Mutex::_no_safepoint_check_flag);
   remove_expired_entries(current_time);
   return longest_pause_internal(current_time);
 }
 double G1MMUTrackerQueue::longest_pause_internal(double current_time) {
   double target_time = _max_gc_time;
   while( 1 ) {
     double gc_time =
       calculate_gc_time(current_time + target_time);
     double diff = target_time + gc_time - _max_gc_time;
     if (!is_double_leq_0(diff)) {
       target_time -= diff;
       if (is_double_leq_0(target_time)) {
         target_time = -1.0;
         break;
       }
     } else {
       break;
     }
   }
   return target_time;
 }
 // basically the _internal call does not remove expired entries
 // this is for trying things out in the future and a couple
 // of other places (debugging)
 double G1MMUTrackerQueue::when_sec(double current_time, double pause_time) {
   if (_DISABLE_MMU)
     return 0.0;
   MutexLockerEx x(MMUTracker_lock, Mutex::_no_safepoint_check_flag);
   remove_expired_entries(current_time);
   return when_internal(current_time, pause_time);
 }
 double G1MMUTrackerQueue::when_internal(double current_time,
                                         double pause_time) {
   // if the pause is over the maximum, just assume that it's the maximum
   double adjusted_pause_time =
     (pause_time > max_gc_time()) ? max_gc_time() : pause_time;
   double earliest_end = current_time + adjusted_pause_time;
   double limit = earliest_end - _time_slice;
   double gc_time = calculate_gc_time(earliest_end);
   double diff = gc_time + adjusted_pause_time - max_gc_time();
   if (is_double_leq_0(diff))
     return 0.0;
   int index = _tail_index;
   while ( 1 ) {
     G1MMUTrackerQueueElem *elem = &_array[index];
     if (elem->end_time() > limit) {
       if (elem->start_time() > limit)
         diff -= elem->duration();
       else
         diff -= elem->end_time() - limit;
       if (is_double_leq_0(diff))
         return  elem->end_time() + diff + _time_slice - adjusted_pause_time - current_time;
     }
     index = trim_index(index+1);
     guarantee(index != trim_index(_head_index + 1), "should not go past head");
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/g1MMUTracker.cpp@b9bc732be7c0 (annotated)

src/share/vm/gc_implementation/g1/g1MMUTracker.cpp