--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMarkThread.cpp Thu Jun 05 15:57:56 2008 -0700
@@ -0,0 +1,336 @@
+/*
+ * 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/_concurrentMarkThread.cpp.incl"
+
+// ======= Concurrent Mark Thread ========
+
+// The CM thread is created when the G1 garbage collector is used
+
+SurrogateLockerThread*
+ ConcurrentMarkThread::_slt = NULL;
+
+ConcurrentMarkThread::ConcurrentMarkThread(ConcurrentMark* cm) :
+ ConcurrentGCThread(),
+ _cm(cm),
+ _started(false),
+ _in_progress(false),
+ _vtime_accum(0.0),
+ _vtime_mark_accum(0.0),
+ _vtime_count_accum(0.0)
+{
+ create_and_start();
+}
+
+class CMCheckpointRootsInitialClosure: public VoidClosure {
+
+ ConcurrentMark* _cm;
+public:
+
+ CMCheckpointRootsInitialClosure(ConcurrentMark* cm) :
+ _cm(cm) {}
+
+ void do_void(){
+ _cm->checkpointRootsInitial();
+ }
+};
+
+class CMCheckpointRootsFinalClosure: public VoidClosure {
+
+ ConcurrentMark* _cm;
+public:
+
+ CMCheckpointRootsFinalClosure(ConcurrentMark* cm) :
+ _cm(cm) {}
+
+ void do_void(){
+ _cm->checkpointRootsFinal(false); // !clear_all_soft_refs
+ }
+};
+
+class CMCleanUp: public VoidClosure {
+ ConcurrentMark* _cm;
+public:
+
+ CMCleanUp(ConcurrentMark* cm) :
+ _cm(cm) {}
+
+ void do_void(){
+ _cm->cleanup();
+ }
+};
+
+
+
+void ConcurrentMarkThread::run() {
+ initialize_in_thread();
+ _vtime_start = os::elapsedVTime();
+ wait_for_universe_init();
+
+ G1CollectedHeap* g1 = G1CollectedHeap::heap();
+ G1CollectorPolicy* g1_policy = g1->g1_policy();
+ G1MMUTracker *mmu_tracker = g1_policy->mmu_tracker();
+ Thread *current_thread = Thread::current();
+
+ while (!_should_terminate) {
+ // wait until started is set.
+ sleepBeforeNextCycle();
+ {
+ ResourceMark rm;
+ HandleMark hm;
+ double cycle_start = os::elapsedVTime();
+ double mark_start_sec = os::elapsedTime();
+ char verbose_str[128];
+
+ if (PrintGC) {
+ gclog_or_tty->date_stamp(PrintGCDateStamps);
+ gclog_or_tty->stamp(PrintGCTimeStamps);
+ tty->print_cr("[GC concurrent-mark-start]");
+ }
+
+ if (!g1_policy->in_young_gc_mode()) {
+ // this ensures the flag is not set if we bail out of the marking
+ // cycle; normally the flag is cleared immediately after cleanup
+ g1->set_marking_complete();
+
+ if (g1_policy->adaptive_young_list_length()) {
+ double now = os::elapsedTime();
+ double init_prediction_ms = g1_policy->predict_init_time_ms();
+ jlong sleep_time_ms = mmu_tracker->when_ms(now, init_prediction_ms);
+ os::sleep(current_thread, sleep_time_ms, false);
+ }
+
+ // We don't have to skip here if we've been asked to restart, because
+ // in the worst case we just enqueue a new VM operation to start a
+ // marking. Note that the init operation resets has_aborted()
+ CMCheckpointRootsInitialClosure init_cl(_cm);
+ strcpy(verbose_str, "GC initial-mark");
+ VM_CGC_Operation op(&init_cl, verbose_str);
+ VMThread::execute(&op);
+ }
+
+ int iter = 0;
+ do {
+ iter++;
+ if (!cm()->has_aborted()) {
+ _cm->markFromRoots();
+ } else {
+ if (TraceConcurrentMark)
+ gclog_or_tty->print_cr("CM-skip-mark-from-roots");
+ }
+
+ double mark_end_time = os::elapsedVTime();
+ double mark_end_sec = os::elapsedTime();
+ _vtime_mark_accum += (mark_end_time - cycle_start);
+ if (!cm()->has_aborted()) {
+ if (g1_policy->adaptive_young_list_length()) {
+ double now = os::elapsedTime();
+ double remark_prediction_ms = g1_policy->predict_remark_time_ms();
+ jlong sleep_time_ms = mmu_tracker->when_ms(now, remark_prediction_ms);
+ os::sleep(current_thread, sleep_time_ms, false);
+ }
+
+ if (PrintGC) {
+ gclog_or_tty->date_stamp(PrintGCDateStamps);
+ gclog_or_tty->stamp(PrintGCTimeStamps);
+ gclog_or_tty->print_cr("[GC concurrent-mark-end, %1.7lf sec]",
+ mark_end_sec - mark_start_sec);
+ }
+
+ CMCheckpointRootsFinalClosure final_cl(_cm);
+ sprintf(verbose_str, "GC remark");
+ VM_CGC_Operation op(&final_cl, verbose_str);
+ VMThread::execute(&op);
+ } else {
+ if (TraceConcurrentMark)
+ gclog_or_tty->print_cr("CM-skip-remark");
+ }
+ if (cm()->restart_for_overflow() &&
+ G1TraceMarkStackOverflow) {
+ gclog_or_tty->print_cr("Restarting conc marking because of MS overflow "
+ "in remark (restart #%d).", iter);
+ }
+
+ if (cm()->restart_for_overflow()) {
+ if (PrintGC) {
+ gclog_or_tty->date_stamp(PrintGCDateStamps);
+ gclog_or_tty->stamp(PrintGCTimeStamps);
+ gclog_or_tty->print_cr("[GC concurrent-mark-restart-for-overflow]");
+ }
+ }
+ } while (cm()->restart_for_overflow());
+ double counting_start_time = os::elapsedVTime();
+
+ // YSR: These look dubious (i.e. redundant) !!! FIX ME
+ slt()->manipulatePLL(SurrogateLockerThread::acquirePLL);
+ slt()->manipulatePLL(SurrogateLockerThread::releaseAndNotifyPLL);
+
+ if (!cm()->has_aborted()) {
+ double count_start_sec = os::elapsedTime();
+ if (PrintGC) {
+ gclog_or_tty->date_stamp(PrintGCDateStamps);
+ gclog_or_tty->stamp(PrintGCTimeStamps);
+ gclog_or_tty->print_cr("[GC concurrent-count-start]");
+ }
+
+ _sts.join();
+ _cm->calcDesiredRegions();
+ _sts.leave();
+
+ if (!cm()->has_aborted()) {
+ double count_end_sec = os::elapsedTime();
+ if (PrintGC) {
+ gclog_or_tty->date_stamp(PrintGCDateStamps);
+ gclog_or_tty->stamp(PrintGCTimeStamps);
+ gclog_or_tty->print_cr("[GC concurrent-count-end, %1.7lf]",
+ count_end_sec - count_start_sec);
+ }
+ }
+ } else {
+ if (TraceConcurrentMark) gclog_or_tty->print_cr("CM-skip-end-game");
+ }
+ double end_time = os::elapsedVTime();
+ _vtime_count_accum += (end_time - counting_start_time);
+ // Update the total virtual time before doing this, since it will try
+ // to measure it to get the vtime for this marking. We purposely
+ // neglect the presumably-short "completeCleanup" phase here.
+ _vtime_accum = (end_time - _vtime_start);
+ if (!cm()->has_aborted()) {
+ if (g1_policy->adaptive_young_list_length()) {
+ double now = os::elapsedTime();
+ double cleanup_prediction_ms = g1_policy->predict_cleanup_time_ms();
+ jlong sleep_time_ms = mmu_tracker->when_ms(now, cleanup_prediction_ms);
+ os::sleep(current_thread, sleep_time_ms, false);
+ }
+
+ CMCleanUp cl_cl(_cm);
+ sprintf(verbose_str, "GC cleanup");
+ VM_CGC_Operation op(&cl_cl, verbose_str);
+ VMThread::execute(&op);
+ } else {
+ if (TraceConcurrentMark) gclog_or_tty->print_cr("CM-skip-cleanup");
+ G1CollectedHeap::heap()->set_marking_complete();
+ }
+
+ if (!cm()->has_aborted()) {
+ double cleanup_start_sec = os::elapsedTime();
+ if (PrintGC) {
+ gclog_or_tty->date_stamp(PrintGCDateStamps);
+ gclog_or_tty->stamp(PrintGCTimeStamps);
+ gclog_or_tty->print_cr("[GC concurrent-cleanup-start]");
+ }
+
+ // Now do the remainder of the cleanup operation.
+ _sts.join();
+ _cm->completeCleanup();
+ if (!cm()->has_aborted()) {
+ g1_policy->record_concurrent_mark_cleanup_completed();
+
+ double cleanup_end_sec = os::elapsedTime();
+ if (PrintGC) {
+ gclog_or_tty->date_stamp(PrintGCDateStamps);
+ gclog_or_tty->stamp(PrintGCTimeStamps);
+ gclog_or_tty->print_cr("[GC concurrent-cleanup-end, %1.7lf]",
+ cleanup_end_sec - cleanup_start_sec);
+ }
+ }
+ _sts.leave();
+ }
+ // We're done: no more unclean regions coming.
+ G1CollectedHeap::heap()->set_unclean_regions_coming(false);
+
+ if (cm()->has_aborted()) {
+ if (PrintGC) {
+ gclog_or_tty->date_stamp(PrintGCDateStamps);
+ gclog_or_tty->stamp(PrintGCTimeStamps);
+ gclog_or_tty->print_cr("[GC concurrent-mark-abort]");
+ }
+ }
+
+ _sts.join();
+ _cm->disable_co_trackers();
+ _sts.leave();
+
+ // we now want to allow clearing of the marking bitmap to be
+ // suspended by a collection pause.
+ _sts.join();
+ _cm->clearNextBitmap();
+ _sts.leave();
+ }
+ }
+ assert(_should_terminate, "just checking");
+
+ terminate();
+}
+
+
+void ConcurrentMarkThread::yield() {
+ if (TraceConcurrentMark) gclog_or_tty->print_cr("CM-yield");
+ _sts.yield("Concurrent Mark");
+ if (TraceConcurrentMark) gclog_or_tty->print_cr("CM-yield-end");
+}
+
+void ConcurrentMarkThread::stop() {
+ // it is ok to take late safepoints here, if needed
+ MutexLockerEx mu(Terminator_lock);
+ _should_terminate = true;
+ while (!_has_terminated) {
+ Terminator_lock->wait();
+ }
+ if (TraceConcurrentMark) gclog_or_tty->print_cr("CM-stop");
+}
+
+void ConcurrentMarkThread::print() {
+ gclog_or_tty->print("\"Concurrent Mark GC Thread\" ");
+ Thread::print();
+ gclog_or_tty->cr();
+}
+
+void ConcurrentMarkThread::sleepBeforeNextCycle() {
+ clear_in_progress();
+ // We join here because we don't want to do the "shouldConcurrentMark()"
+ // below while the world is otherwise stopped.
+ MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag);
+ while (!started()) {
+ if (TraceConcurrentMark) gclog_or_tty->print_cr("CM-sleeping");
+ CGC_lock->wait(Mutex::_no_safepoint_check_flag);
+ }
+ set_in_progress();
+ clear_started();
+ if (TraceConcurrentMark) gclog_or_tty->print_cr("CM-starting");
+
+ return;
+}
+
+// Note: this method, although exported by the ConcurrentMarkSweepThread,
+// which is a non-JavaThread, can only be called by a JavaThread.
+// Currently this is done at vm creation time (post-vm-init) by the
+// main/Primordial (Java)Thread.
+// XXX Consider changing this in the future to allow the CMS thread
+// itself to create this thread?
+void ConcurrentMarkThread::makeSurrogateLockerThread(TRAPS) {
+ assert(_slt == NULL, "SLT already created");
+ _slt = SurrogateLockerThread::make(THREAD);
+}