src/hotspot/share/gc/g1/concurrentG1RefineThread.cpp
branchhttp-client-branch
changeset 55820 76d033c9908f
parent 55819 18e431209168
parent 47825 13e39ca700d0
child 55821 fa0fc03c0853
equal deleted inserted replaced
55819:18e431209168 55820:76d033c9908f
     1 /*
       
     2  * Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
       
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
       
     4  *
       
     5  * This code is free software; you can redistribute it and/or modify it
       
     6  * under the terms of the GNU General Public License version 2 only, as
       
     7  * published by the Free Software Foundation.
       
     8  *
       
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
       
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
       
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
       
    12  * version 2 for more details (a copy is included in the LICENSE file that
       
    13  * accompanied this code).
       
    14  *
       
    15  * You should have received a copy of the GNU General Public License version
       
    16  * 2 along with this work; if not, write to the Free Software Foundation,
       
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
       
    18  *
       
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
       
    20  * or visit www.oracle.com if you need additional information or have any
       
    21  * questions.
       
    22  *
       
    23  */
       
    24 
       
    25 #include "precompiled.hpp"
       
    26 #include "gc/g1/concurrentG1Refine.hpp"
       
    27 #include "gc/g1/concurrentG1RefineThread.hpp"
       
    28 #include "gc/g1/g1CollectedHeap.inline.hpp"
       
    29 #include "gc/g1/g1RemSet.hpp"
       
    30 #include "gc/shared/suspendibleThreadSet.hpp"
       
    31 #include "logging/log.hpp"
       
    32 #include "memory/resourceArea.hpp"
       
    33 #include "runtime/handles.inline.hpp"
       
    34 #include "runtime/mutexLocker.hpp"
       
    35 
       
    36 ConcurrentG1RefineThread::
       
    37 ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r, ConcurrentG1RefineThread *next,
       
    38                          uint worker_id_offset, uint worker_id,
       
    39                          size_t activate, size_t deactivate) :
       
    40   ConcurrentGCThread(),
       
    41   _worker_id_offset(worker_id_offset),
       
    42   _worker_id(worker_id),
       
    43   _active(false),
       
    44   _next(next),
       
    45   _monitor(NULL),
       
    46   _cg1r(cg1r),
       
    47   _vtime_accum(0.0),
       
    48   _activation_threshold(activate),
       
    49   _deactivation_threshold(deactivate)
       
    50 {
       
    51 
       
    52   // Each thread has its own monitor. The i-th thread is responsible for signaling
       
    53   // to thread i+1 if the number of buffers in the queue exceeds a threshold for this
       
    54   // thread. Monitors are also used to wake up the threads during termination.
       
    55   // The 0th (primary) worker is notified by mutator threads and has a special monitor.
       
    56   if (!is_primary()) {
       
    57     _monitor = new Monitor(Mutex::nonleaf, "Refinement monitor", true,
       
    58                            Monitor::_safepoint_check_never);
       
    59   } else {
       
    60     _monitor = DirtyCardQ_CBL_mon;
       
    61   }
       
    62 
       
    63   // set name
       
    64   set_name("G1 Refine#%d", worker_id);
       
    65   create_and_start();
       
    66 }
       
    67 
       
    68 void ConcurrentG1RefineThread::update_thresholds(size_t activate,
       
    69                                                  size_t deactivate) {
       
    70   assert(deactivate < activate, "precondition");
       
    71   _activation_threshold = activate;
       
    72   _deactivation_threshold = deactivate;
       
    73 }
       
    74 
       
    75 void ConcurrentG1RefineThread::wait_for_completed_buffers() {
       
    76   MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
       
    77   while (!should_terminate() && !is_active()) {
       
    78     _monitor->wait(Mutex::_no_safepoint_check_flag);
       
    79   }
       
    80 }
       
    81 
       
    82 bool ConcurrentG1RefineThread::is_active() {
       
    83   DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
       
    84   return is_primary() ? dcqs.process_completed_buffers() : _active;
       
    85 }
       
    86 
       
    87 void ConcurrentG1RefineThread::activate() {
       
    88   MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
       
    89   if (!is_primary()) {
       
    90     set_active(true);
       
    91   } else {
       
    92     DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
       
    93     dcqs.set_process_completed(true);
       
    94   }
       
    95   _monitor->notify();
       
    96 }
       
    97 
       
    98 void ConcurrentG1RefineThread::deactivate() {
       
    99   MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
       
   100   if (!is_primary()) {
       
   101     set_active(false);
       
   102   } else {
       
   103     DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
       
   104     dcqs.set_process_completed(false);
       
   105   }
       
   106 }
       
   107 
       
   108 void ConcurrentG1RefineThread::run_service() {
       
   109   _vtime_start = os::elapsedVTime();
       
   110 
       
   111   while (!should_terminate()) {
       
   112     // Wait for work
       
   113     wait_for_completed_buffers();
       
   114     if (should_terminate()) {
       
   115       break;
       
   116     }
       
   117 
       
   118     size_t buffers_processed = 0;
       
   119     DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
       
   120     log_debug(gc, refine)("Activated %d, on threshold: " SIZE_FORMAT ", current: " SIZE_FORMAT,
       
   121                           _worker_id, _activation_threshold, dcqs.completed_buffers_num());
       
   122 
       
   123     {
       
   124       SuspendibleThreadSetJoiner sts_join;
       
   125 
       
   126       while (!should_terminate()) {
       
   127         if (sts_join.should_yield()) {
       
   128           sts_join.yield();
       
   129           continue;             // Re-check for termination after yield delay.
       
   130         }
       
   131 
       
   132         size_t curr_buffer_num = dcqs.completed_buffers_num();
       
   133         // If the number of the buffers falls down into the yellow zone,
       
   134         // that means that the transition period after the evacuation pause has ended.
       
   135         if (dcqs.completed_queue_padding() > 0 && curr_buffer_num <= cg1r()->yellow_zone()) {
       
   136           dcqs.set_completed_queue_padding(0);
       
   137         }
       
   138 
       
   139         // Check if we need to activate the next thread.
       
   140         if ((_next != NULL) &&
       
   141             !_next->is_active() &&
       
   142             (curr_buffer_num > _next->_activation_threshold)) {
       
   143           _next->activate();
       
   144         }
       
   145 
       
   146         // Process the next buffer, if there are enough left.
       
   147         if (!dcqs.refine_completed_buffer_concurrently(_worker_id + _worker_id_offset, _deactivation_threshold)) {
       
   148           break; // Deactivate, number of buffers fell below threshold.
       
   149         }
       
   150         ++buffers_processed;
       
   151       }
       
   152     }
       
   153 
       
   154     deactivate();
       
   155     log_debug(gc, refine)("Deactivated %d, off threshold: " SIZE_FORMAT
       
   156                           ", current: " SIZE_FORMAT ", processed: " SIZE_FORMAT,
       
   157                           _worker_id, _deactivation_threshold,
       
   158                           dcqs.completed_buffers_num(),
       
   159                           buffers_processed);
       
   160 
       
   161     if (os::supports_vtime()) {
       
   162       _vtime_accum = (os::elapsedVTime() - _vtime_start);
       
   163     } else {
       
   164       _vtime_accum = 0.0;
       
   165     }
       
   166   }
       
   167 
       
   168   log_debug(gc, refine)("Stopping %d", _worker_id);
       
   169 }
       
   170 
       
   171 void ConcurrentG1RefineThread::stop_service() {
       
   172   MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
       
   173   _monitor->notify();
       
   174 }