diff -r 570062d730b2 -r 4c24294029a9 hotspot/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp Thu Jun 05 15:57:56 2008 -0700 @@ -0,0 +1,246 @@ +/* + * Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +#include "incls/_precompiled.incl" +#include "incls/_concurrentG1RefineThread.cpp.incl" + +// ======= Concurrent Mark Thread ======== + +// The CM thread is created when the G1 garbage collector is used + +ConcurrentG1RefineThread:: +ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r) : + ConcurrentGCThread(), + _cg1r(cg1r), + _started(false), + _in_progress(false), + _do_traversal(false), + _vtime_accum(0.0), + _co_tracker(G1CRGroup), + _interval_ms(5.0) +{ + create_and_start(); +} + +const long timeout = 200; // ms. + +void ConcurrentG1RefineThread::traversalBasedRefinement() { + _cg1r->wait_for_ConcurrentG1Refine_enabled(); + MutexLocker x(G1ConcRefine_mon); + while (_cg1r->enabled()) { + MutexUnlocker ux(G1ConcRefine_mon); + ResourceMark rm; + HandleMark hm; + + if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine starting pass"); + _sts.join(); + bool no_sleep = _cg1r->refine(); + _sts.leave(); + if (!no_sleep) { + MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag); + // We do this only for the timeout; we don't expect this to be signalled. + CGC_lock->wait(Mutex::_no_safepoint_check_flag, timeout); + } + } +} + +void ConcurrentG1RefineThread::queueBasedRefinement() { + DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); + // Wait for completed log buffers to exist. + { + MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag); + while (!_do_traversal && !dcqs.process_completed_buffers() && + !_should_terminate) { + DirtyCardQ_CBL_mon->wait(Mutex::_no_safepoint_check_flag); + } + } + + if (_should_terminate) { + return; + } + + // Now we take them off (this doesn't hold locks while it applies + // closures.) (If we did a full collection, then we'll do a full + // traversal. + _sts.join(); + if (_do_traversal) { + (void)_cg1r->refine(); + switch (_cg1r->get_last_pya()) { + case PYA_cancel: case PYA_continue: + // Continue was caught and handled inside "refine". If it's still + // "continue" when we get here, we're done. + _do_traversal = false; + break; + case PYA_restart: + assert(_do_traversal, "Because of Full GC."); + break; + } + } else { + int n_logs = 0; + int lower_limit = 0; + double start_vtime_sec; // only used when G1SmoothConcRefine is on + int prev_buffer_num; // only used when G1SmoothConcRefine is on + + if (G1SmoothConcRefine) { + lower_limit = 0; + start_vtime_sec = os::elapsedVTime(); + prev_buffer_num = (int) dcqs.completed_buffers_num(); + } else { + lower_limit = DCQBarrierProcessCompletedThreshold / 4; // For now. + } + while (dcqs.apply_closure_to_completed_buffer(0, lower_limit)) { + double end_vtime_sec; + double elapsed_vtime_sec; + int elapsed_vtime_ms; + int curr_buffer_num; + + if (G1SmoothConcRefine) { + end_vtime_sec = os::elapsedVTime(); + elapsed_vtime_sec = end_vtime_sec - start_vtime_sec; + elapsed_vtime_ms = (int) (elapsed_vtime_sec * 1000.0); + curr_buffer_num = (int) dcqs.completed_buffers_num(); + + if (curr_buffer_num > prev_buffer_num || + curr_buffer_num > DCQBarrierProcessCompletedThreshold) { + decreaseInterval(elapsed_vtime_ms); + } else if (curr_buffer_num < prev_buffer_num) { + increaseInterval(elapsed_vtime_ms); + } + } + + sample_young_list_rs_lengths(); + _co_tracker.update(false); + + if (G1SmoothConcRefine) { + start_vtime_sec = os::elapsedVTime(); + prev_buffer_num = curr_buffer_num; + + _sts.leave(); + os::sleep(Thread::current(), (jlong) _interval_ms, false); + _sts.join(); + } + + n_logs++; + } + // Make sure we harvest the PYA, if any. + (void)_cg1r->get_pya(); + } + _sts.leave(); +} + +void ConcurrentG1RefineThread::sample_young_list_rs_lengths() { + G1CollectedHeap* g1h = G1CollectedHeap::heap(); + G1CollectorPolicy* g1p = g1h->g1_policy(); + if (g1p->adaptive_young_list_length()) { + int regions_visited = 0; + + g1h->young_list_rs_length_sampling_init(); + while (g1h->young_list_rs_length_sampling_more()) { + g1h->young_list_rs_length_sampling_next(); + ++regions_visited; + + // we try to yield every time we visit 10 regions + if (regions_visited == 10) { + if (_sts.should_yield()) { + _sts.yield("G1 refine"); + // we just abandon the iteration + break; + } + regions_visited = 0; + } + } + + g1p->check_prediction_validity(); + } +} + +void ConcurrentG1RefineThread::run() { + initialize_in_thread(); + _vtime_start = os::elapsedVTime(); + wait_for_universe_init(); + + _co_tracker.enable(); + _co_tracker.start(); + + while (!_should_terminate) { + // wait until started is set. + if (G1RSBarrierUseQueue) { + queueBasedRefinement(); + } else { + traversalBasedRefinement(); + } + _sts.join(); + _co_tracker.update(); + _sts.leave(); + if (os::supports_vtime()) { + _vtime_accum = (os::elapsedVTime() - _vtime_start); + } else { + _vtime_accum = 0.0; + } + } + _sts.join(); + _co_tracker.update(true); + _sts.leave(); + assert(_should_terminate, "just checking"); + + terminate(); +} + + +void ConcurrentG1RefineThread::yield() { + if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine-yield"); + _sts.yield("G1 refine"); + if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine-yield-end"); +} + +void ConcurrentG1RefineThread::stop() { + // it is ok to take late safepoints here, if needed + { + MutexLockerEx mu(Terminator_lock); + _should_terminate = true; + } + + { + MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag); + DirtyCardQ_CBL_mon->notify_all(); + } + + { + MutexLockerEx mu(Terminator_lock); + while (!_has_terminated) { + Terminator_lock->wait(); + } + } + if (TraceG1Refine) gclog_or_tty->print_cr("G1-Refine-stop"); +} + +void ConcurrentG1RefineThread::print() { + gclog_or_tty->print("\"Concurrent G1 Refinement Thread\" "); + Thread::print(); + gclog_or_tty->cr(); +} + +void ConcurrentG1RefineThread::set_do_traversal(bool b) { + _do_traversal = b; +}