1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp Thu Jun 05 15:57:56 2008 -0700
1.3 @@ -0,0 +1,246 @@
1.4 +/*
1.5 + * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "incls/_precompiled.incl"
1.29 +#include "incls/_concurrentG1RefineThread.cpp.incl"
1.30 +
1.31 +// ======= Concurrent Mark Thread ========
1.32 +
1.33 +// The CM thread is created when the G1 garbage collector is used
1.34 +
1.35 +ConcurrentG1RefineThread::
1.36 +ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r) :
1.37 + ConcurrentGCThread(),
1.38 + _cg1r(cg1r),
1.39 + _started(false),
1.40 + _in_progress(false),
1.41 + _do_traversal(false),
1.42 + _vtime_accum(0.0),
1.43 + _co_tracker(G1CRGroup),
1.44 + _interval_ms(5.0)
1.45 +{
1.46 + create_and_start();
1.47 +}
1.48 +
1.49 +const long timeout = 200; // ms.
1.50 +
1.51 +void ConcurrentG1RefineThread::traversalBasedRefinement() {
1.52 + _cg1r->wait_for_ConcurrentG1Refine_enabled();
1.53 + MutexLocker x(G1ConcRefine_mon);
1.54 + while (_cg1r->enabled()) {
1.55 + MutexUnlocker ux(G1ConcRefine_mon);
1.56 + ResourceMark rm;
1.57 + HandleMark hm;
1.58 +
1.59 + if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine starting pass");
1.60 + _sts.join();
1.61 + bool no_sleep = _cg1r->refine();
1.62 + _sts.leave();
1.63 + if (!no_sleep) {
1.64 + MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag);
1.65 + // We do this only for the timeout; we don't expect this to be signalled.
1.66 + CGC_lock->wait(Mutex::_no_safepoint_check_flag, timeout);
1.67 + }
1.68 + }
1.69 +}
1.70 +
1.71 +void ConcurrentG1RefineThread::queueBasedRefinement() {
1.72 + DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
1.73 + // Wait for completed log buffers to exist.
1.74 + {
1.75 + MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
1.76 + while (!_do_traversal && !dcqs.process_completed_buffers() &&
1.77 + !_should_terminate) {
1.78 + DirtyCardQ_CBL_mon->wait(Mutex::_no_safepoint_check_flag);
1.79 + }
1.80 + }
1.81 +
1.82 + if (_should_terminate) {
1.83 + return;
1.84 + }
1.85 +
1.86 + // Now we take them off (this doesn't hold locks while it applies
1.87 + // closures.) (If we did a full collection, then we'll do a full
1.88 + // traversal.
1.89 + _sts.join();
1.90 + if (_do_traversal) {
1.91 + (void)_cg1r->refine();
1.92 + switch (_cg1r->get_last_pya()) {
1.93 + case PYA_cancel: case PYA_continue:
1.94 + // Continue was caught and handled inside "refine". If it's still
1.95 + // "continue" when we get here, we're done.
1.96 + _do_traversal = false;
1.97 + break;
1.98 + case PYA_restart:
1.99 + assert(_do_traversal, "Because of Full GC.");
1.100 + break;
1.101 + }
1.102 + } else {
1.103 + int n_logs = 0;
1.104 + int lower_limit = 0;
1.105 + double start_vtime_sec; // only used when G1SmoothConcRefine is on
1.106 + int prev_buffer_num; // only used when G1SmoothConcRefine is on
1.107 +
1.108 + if (G1SmoothConcRefine) {
1.109 + lower_limit = 0;
1.110 + start_vtime_sec = os::elapsedVTime();
1.111 + prev_buffer_num = (int) dcqs.completed_buffers_num();
1.112 + } else {
1.113 + lower_limit = DCQBarrierProcessCompletedThreshold / 4; // For now.
1.114 + }
1.115 + while (dcqs.apply_closure_to_completed_buffer(0, lower_limit)) {
1.116 + double end_vtime_sec;
1.117 + double elapsed_vtime_sec;
1.118 + int elapsed_vtime_ms;
1.119 + int curr_buffer_num;
1.120 +
1.121 + if (G1SmoothConcRefine) {
1.122 + end_vtime_sec = os::elapsedVTime();
1.123 + elapsed_vtime_sec = end_vtime_sec - start_vtime_sec;
1.124 + elapsed_vtime_ms = (int) (elapsed_vtime_sec * 1000.0);
1.125 + curr_buffer_num = (int) dcqs.completed_buffers_num();
1.126 +
1.127 + if (curr_buffer_num > prev_buffer_num ||
1.128 + curr_buffer_num > DCQBarrierProcessCompletedThreshold) {
1.129 + decreaseInterval(elapsed_vtime_ms);
1.130 + } else if (curr_buffer_num < prev_buffer_num) {
1.131 + increaseInterval(elapsed_vtime_ms);
1.132 + }
1.133 + }
1.134 +
1.135 + sample_young_list_rs_lengths();
1.136 + _co_tracker.update(false);
1.137 +
1.138 + if (G1SmoothConcRefine) {
1.139 + start_vtime_sec = os::elapsedVTime();
1.140 + prev_buffer_num = curr_buffer_num;
1.141 +
1.142 + _sts.leave();
1.143 + os::sleep(Thread::current(), (jlong) _interval_ms, false);
1.144 + _sts.join();
1.145 + }
1.146 +
1.147 + n_logs++;
1.148 + }
1.149 + // Make sure we harvest the PYA, if any.
1.150 + (void)_cg1r->get_pya();
1.151 + }
1.152 + _sts.leave();
1.153 +}
1.154 +
1.155 +void ConcurrentG1RefineThread::sample_young_list_rs_lengths() {
1.156 + G1CollectedHeap* g1h = G1CollectedHeap::heap();
1.157 + G1CollectorPolicy* g1p = g1h->g1_policy();
1.158 + if (g1p->adaptive_young_list_length()) {
1.159 + int regions_visited = 0;
1.160 +
1.161 + g1h->young_list_rs_length_sampling_init();
1.162 + while (g1h->young_list_rs_length_sampling_more()) {
1.163 + g1h->young_list_rs_length_sampling_next();
1.164 + ++regions_visited;
1.165 +
1.166 + // we try to yield every time we visit 10 regions
1.167 + if (regions_visited == 10) {
1.168 + if (_sts.should_yield()) {
1.169 + _sts.yield("G1 refine");
1.170 + // we just abandon the iteration
1.171 + break;
1.172 + }
1.173 + regions_visited = 0;
1.174 + }
1.175 + }
1.176 +
1.177 + g1p->check_prediction_validity();
1.178 + }
1.179 +}
1.180 +
1.181 +void ConcurrentG1RefineThread::run() {
1.182 + initialize_in_thread();
1.183 + _vtime_start = os::elapsedVTime();
1.184 + wait_for_universe_init();
1.185 +
1.186 + _co_tracker.enable();
1.187 + _co_tracker.start();
1.188 +
1.189 + while (!_should_terminate) {
1.190 + // wait until started is set.
1.191 + if (G1RSBarrierUseQueue) {
1.192 + queueBasedRefinement();
1.193 + } else {
1.194 + traversalBasedRefinement();
1.195 + }
1.196 + _sts.join();
1.197 + _co_tracker.update();
1.198 + _sts.leave();
1.199 + if (os::supports_vtime()) {
1.200 + _vtime_accum = (os::elapsedVTime() - _vtime_start);
1.201 + } else {
1.202 + _vtime_accum = 0.0;
1.203 + }
1.204 + }
1.205 + _sts.join();
1.206 + _co_tracker.update(true);
1.207 + _sts.leave();
1.208 + assert(_should_terminate, "just checking");
1.209 +
1.210 + terminate();
1.211 +}
1.212 +
1.213 +
1.214 +void ConcurrentG1RefineThread::yield() {
1.215 + if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine-yield");
1.216 + _sts.yield("G1 refine");
1.217 + if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine-yield-end");
1.218 +}
1.219 +
1.220 +void ConcurrentG1RefineThread::stop() {
1.221 + // it is ok to take late safepoints here, if needed
1.222 + {
1.223 + MutexLockerEx mu(Terminator_lock);
1.224 + _should_terminate = true;
1.225 + }
1.226 +
1.227 + {
1.228 + MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
1.229 + DirtyCardQ_CBL_mon->notify_all();
1.230 + }
1.231 +
1.232 + {
1.233 + MutexLockerEx mu(Terminator_lock);
1.234 + while (!_has_terminated) {
1.235 + Terminator_lock->wait();
1.236 + }
1.237 + }
1.238 + if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine-stop");
1.239 +}
1.240 +
1.241 +void ConcurrentG1RefineThread::print() {
1.242 + gclog_or_tty->print("\"Concurrent G1 Refinement Thread\" ");
1.243 + Thread::print();
1.244 + gclog_or_tty->cr();
1.245 +}
1.246 +
1.247 +void ConcurrentG1RefineThread::set_do_traversal(bool b) {
1.248 + _do_traversal = b;
1.249 +}
