ysr@777: /*
trims@1907:  * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
ysr@777:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@777:  *
ysr@777:  * This code is free software; you can redistribute it and/or modify it
ysr@777:  * under the terms of the GNU General Public License version 2 only, as
ysr@777:  * published by the Free Software Foundation.
ysr@777:  *
ysr@777:  * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@777:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@777:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ysr@777:  * version 2 for more details (a copy is included in the LICENSE file that
ysr@777:  * accompanied this code).
ysr@777:  *
ysr@777:  * You should have received a copy of the GNU General Public License version
ysr@777:  * 2 along with this work; if not, write to the Free Software Foundation,
ysr@777:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@777:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
ysr@777:  *
ysr@777:  */
ysr@777: 
stefank@2314: #include "precompiled.hpp"
stefank@2314: #include "gc_implementation/g1/concurrentG1Refine.hpp"
stefank@2314: #include "gc_implementation/g1/concurrentG1RefineThread.hpp"
stefank@2314: #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
stefank@2314: #include "gc_implementation/g1/g1CollectorPolicy.hpp"
stefank@2314: #include "memory/resourceArea.hpp"
stefank@2314: #include "runtime/handles.inline.hpp"
stefank@2314: #include "runtime/mutexLocker.hpp"
ysr@777: 
ysr@777: ConcurrentG1RefineThread::
iveresov@1230: ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r, ConcurrentG1RefineThread *next,
iveresov@1230:                          int worker_id_offset, int worker_id) :
ysr@777:   ConcurrentGCThread(),
iveresov@1230:   _worker_id_offset(worker_id_offset),
iveresov@1229:   _worker_id(worker_id),
iveresov@1229:   _active(false),
iveresov@1229:   _next(next),
iveresov@1546:   _monitor(NULL),
ysr@777:   _cg1r(cg1r),
iveresov@1546:   _vtime_accum(0.0)
ysr@777: {
iveresov@1546: 
iveresov@1546:   // Each thread has its own monitor. The i-th thread is responsible for signalling
iveresov@1546:   // to thread i+1 if the number of buffers in the queue exceeds a threashold for this
iveresov@1546:   // thread. Monitors are also used to wake up the threads during termination.
iveresov@1546:   // The 0th worker in notified by mutator threads and has a special monitor.
iveresov@1546:   // The last worker is used for young gen rset size sampling.
iveresov@1546:   if (worker_id > 0) {
iveresov@1546:     _monitor = new Monitor(Mutex::nonleaf, "Refinement monitor", true);
iveresov@1546:   } else {
iveresov@1546:     _monitor = DirtyCardQ_CBL_mon;
iveresov@1546:   }
iveresov@1546:   initialize();
ysr@777:   create_and_start();
ysr@777: }
ysr@777: 
iveresov@1546: void ConcurrentG1RefineThread::initialize() {
iveresov@1546:   if (_worker_id < cg1r()->worker_thread_num()) {
iveresov@1546:     // Current thread activation threshold
iveresov@1546:     _threshold = MIN2<int>(cg1r()->thread_threshold_step() * (_worker_id + 1) + cg1r()->green_zone(),
iveresov@1546:                            cg1r()->yellow_zone());
iveresov@1546:     // A thread deactivates once the number of buffer reached a deactivation threshold
iveresov@1546:     _deactivation_threshold = MAX2<int>(_threshold - cg1r()->thread_threshold_step(), cg1r()->green_zone());
iveresov@1546:   } else {
iveresov@1546:     set_active(true);
iveresov@1546:   }
iveresov@1546: }
iveresov@1546: 
ysr@777: void ConcurrentG1RefineThread::sample_young_list_rs_lengths() {
ysr@777:   G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777:   G1CollectorPolicy* g1p = g1h->g1_policy();
ysr@777:   if (g1p->adaptive_young_list_length()) {
ysr@777:     int regions_visited = 0;
johnc@1829:     g1h->young_list()->rs_length_sampling_init();
johnc@1829:     while (g1h->young_list()->rs_length_sampling_more()) {
johnc@1829:       g1h->young_list()->rs_length_sampling_next();
ysr@777:       ++regions_visited;
ysr@777: 
ysr@777:       // we try to yield every time we visit 10 regions
ysr@777:       if (regions_visited == 10) {
ysr@777:         if (_sts.should_yield()) {
ysr@777:           _sts.yield("G1 refine");
ysr@777:           // we just abandon the iteration
ysr@777:           break;
ysr@777:         }
ysr@777:         regions_visited = 0;
ysr@777:       }
ysr@777:     }
ysr@777: 
tonyp@3119:     g1p->revise_young_list_target_length_if_necessary();
ysr@777:   }
ysr@777: }
ysr@777: 
iveresov@1546: void ConcurrentG1RefineThread::run_young_rs_sampling() {
iveresov@1546:   DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
iveresov@1546:   _vtime_start = os::elapsedVTime();
iveresov@1546:   while(!_should_terminate) {
iveresov@1546:     _sts.join();
iveresov@1546:     sample_young_list_rs_lengths();
iveresov@1546:     _sts.leave();
iveresov@1546: 
iveresov@1546:     if (os::supports_vtime()) {
iveresov@1546:       _vtime_accum = (os::elapsedVTime() - _vtime_start);
iveresov@1546:     } else {
iveresov@1546:       _vtime_accum = 0.0;
iveresov@1546:     }
iveresov@1546: 
iveresov@1546:     MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
iveresov@1546:     if (_should_terminate) {
iveresov@1546:       break;
iveresov@1546:     }
tonyp@1717:     _monitor->wait(Mutex::_no_safepoint_check_flag, G1ConcRefinementServiceIntervalMillis);
iveresov@1546:   }
iveresov@1546: }
iveresov@1546: 
iveresov@1546: void ConcurrentG1RefineThread::wait_for_completed_buffers() {
iveresov@1546:   DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
iveresov@1546:   MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
iveresov@1546:   while (!_should_terminate && !is_active()) {
iveresov@1546:     _monitor->wait(Mutex::_no_safepoint_check_flag);
iveresov@1546:   }
iveresov@1546: }
iveresov@1546: 
iveresov@1546: bool ConcurrentG1RefineThread::is_active() {
iveresov@1546:   DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
iveresov@1546:   return _worker_id > 0 ? _active : dcqs.process_completed_buffers();
iveresov@1546: }
iveresov@1546: 
iveresov@1546: void ConcurrentG1RefineThread::activate() {
iveresov@1546:   MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
iveresov@1546:   if (_worker_id > 0) {
tonyp@1717:     if (G1TraceConcRefinement) {
iveresov@1546:       DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
iveresov@1546:       gclog_or_tty->print_cr("G1-Refine-activated worker %d, on threshold %d, current %d",
iveresov@1546:                              _worker_id, _threshold, (int)dcqs.completed_buffers_num());
iveresov@1546:     }
iveresov@1546:     set_active(true);
iveresov@1546:   } else {
iveresov@1546:     DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
iveresov@1546:     dcqs.set_process_completed(true);
iveresov@1546:   }
iveresov@1546:   _monitor->notify();
iveresov@1546: }
iveresov@1546: 
iveresov@1546: void ConcurrentG1RefineThread::deactivate() {
iveresov@1546:   MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
iveresov@1546:   if (_worker_id > 0) {
tonyp@1717:     if (G1TraceConcRefinement) {
iveresov@1546:       DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
iveresov@1546:       gclog_or_tty->print_cr("G1-Refine-deactivated worker %d, off threshold %d, current %d",
iveresov@1546:                              _worker_id, _deactivation_threshold, (int)dcqs.completed_buffers_num());
iveresov@1546:     }
iveresov@1546:     set_active(false);
iveresov@1546:   } else {
iveresov@1546:     DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
iveresov@1546:     dcqs.set_process_completed(false);
iveresov@1546:   }
iveresov@1546: }
iveresov@1546: 
ysr@777: void ConcurrentG1RefineThread::run() {
ysr@777:   initialize_in_thread();
ysr@777:   wait_for_universe_init();
ysr@777: 
iveresov@1546:   if (_worker_id >= cg1r()->worker_thread_num()) {
iveresov@1546:     run_young_rs_sampling();
iveresov@1546:     terminate();
johnc@1829:     return;
iveresov@1546:   }
iveresov@1546: 
iveresov@1546:   _vtime_start = os::elapsedVTime();
ysr@777:   while (!_should_terminate) {
iveresov@1229:     DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
iveresov@1546: 
iveresov@1546:     // Wait for work
iveresov@1546:     wait_for_completed_buffers();
iveresov@1546: 
iveresov@1546:     if (_should_terminate) {
iveresov@1546:       break;
iveresov@1229:     }
iveresov@1229: 
iveresov@1546:     _sts.join();
iveresov@1229: 
iveresov@1546:     do {
iveresov@1546:       int curr_buffer_num = (int)dcqs.completed_buffers_num();
iveresov@1546:       // If the number of the buffers falls down into the yellow zone,
iveresov@1546:       // that means that the transition period after the evacuation pause has ended.
iveresov@1546:       if (dcqs.completed_queue_padding() > 0 && curr_buffer_num <= cg1r()->yellow_zone()) {
iveresov@1546:         dcqs.set_completed_queue_padding(0);
iveresov@1546:       }
iveresov@1229: 
iveresov@1546:       if (_worker_id > 0 && curr_buffer_num <= _deactivation_threshold) {
iveresov@1229:         // If the number of the buffer has fallen below our threshold
iveresov@1229:         // we should deactivate. The predecessor will reactivate this
iveresov@1229:         // thread should the number of the buffers cross the threshold again.
iveresov@1229:         deactivate();
iveresov@1229:         break;
iveresov@1229:       }
iveresov@1229: 
iveresov@1229:       // Check if we need to activate the next thread.
iveresov@1546:       if (_next != NULL && !_next->is_active() && curr_buffer_num > _next->_threshold) {
iveresov@1229:         _next->activate();
iveresov@1229:       }
iveresov@1546:     } while (dcqs.apply_closure_to_completed_buffer(_worker_id + _worker_id_offset, cg1r()->green_zone()));
iveresov@1229: 
iveresov@1546:     // We can exit the loop above while being active if there was a yield request.
iveresov@1546:     if (is_active()) {
iveresov@1546:       deactivate();
iveresov@1229:     }
iveresov@1546: 
ysr@777:     _sts.leave();
iveresov@1229: 
ysr@777:     if (os::supports_vtime()) {
ysr@777:       _vtime_accum = (os::elapsedVTime() - _vtime_start);
ysr@777:     } else {
ysr@777:       _vtime_accum = 0.0;
ysr@777:     }
ysr@777:   }
ysr@777:   assert(_should_terminate, "just checking");
ysr@777:   terminate();
ysr@777: }
ysr@777: 
ysr@777: 
ysr@777: void ConcurrentG1RefineThread::yield() {
tonyp@1717:   if (G1TraceConcRefinement) {
tonyp@1717:     gclog_or_tty->print_cr("G1-Refine-yield");
tonyp@1717:   }
ysr@777:   _sts.yield("G1 refine");
tonyp@1717:   if (G1TraceConcRefinement) {
tonyp@1717:     gclog_or_tty->print_cr("G1-Refine-yield-end");
tonyp@1717:   }
ysr@777: }
ysr@777: 
ysr@777: void ConcurrentG1RefineThread::stop() {
ysr@777:   // it is ok to take late safepoints here, if needed
ysr@777:   {
ysr@777:     MutexLockerEx mu(Terminator_lock);
ysr@777:     _should_terminate = true;
ysr@777:   }
ysr@777: 
ysr@777:   {
iveresov@1546:     MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
iveresov@1546:     _monitor->notify();
ysr@777:   }
ysr@777: 
ysr@777:   {
ysr@777:     MutexLockerEx mu(Terminator_lock);
ysr@777:     while (!_has_terminated) {
ysr@777:       Terminator_lock->wait();
ysr@777:     }
ysr@777:   }
tonyp@1717:   if (G1TraceConcRefinement) {
tonyp@1717:     gclog_or_tty->print_cr("G1-Refine-stop");
tonyp@1717:   }
ysr@777: }
ysr@777: 
tonyp@1454: void ConcurrentG1RefineThread::print() const {
tonyp@1454:   print_on(tty);
ysr@777: }
tonyp@1454: 
tonyp@1454: void ConcurrentG1RefineThread::print_on(outputStream* st) const {
tonyp@1454:   st->print("\"G1 Concurrent Refinement Thread#%d\" ", _worker_id);
tonyp@1454:   Thread::print_on(st);
tonyp@1454:   st->cr();
tonyp@1454: }