--- /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;
+}