| /* |
| * Copyright (c) 2001, 2011, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "gc_implementation/g1/concurrentMarkThread.inline.hpp" |
| #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" |
| #include "gc_implementation/g1/g1CollectorPolicy.hpp" |
| #include "gc_implementation/g1/g1MMUTracker.hpp" |
| #include "gc_implementation/g1/vm_operations_g1.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "runtime/vmThread.hpp" |
| |
| // ======= 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* g1h = G1CollectedHeap::heap(); |
| G1CollectorPolicy* g1_policy = g1h->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); |
| gclog_or_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 |
| g1h->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(); |
| } |
| |
| 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); |
| } |
| 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); |
| } |
| } |
| } |
| 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 { |
| g1h->set_marking_complete(); |
| } |
| |
| // Check if cleanup set the free_regions_coming flag. If it |
| // hasn't, we can just skip the next step. |
| if (g1h->free_regions_coming()) { |
| // The following will finish freeing up any regions that we |
| // found to be empty during cleanup. We'll do this part |
| // without joining the suspendible set. If an evacuation pause |
| // takes places, then we would carry on freeing regions in |
| // case they are needed by the pause. If a Full GC takes |
| // places, it would wait for us to process the regions |
| // reclaimed by cleanup. |
| |
| 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. |
| _cm->completeCleanup(); |
| 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); |
| } |
| |
| // We're done: no more free regions coming. |
| g1h->reset_free_regions_coming(); |
| } |
| guarantee(cm()->cleanup_list_is_empty(), |
| "at this point there should be no regions on the cleanup list"); |
| |
| 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]"); |
| } |
| } |
| |
| // we now want to allow clearing of the marking bitmap to be |
| // suspended by a collection pause. |
| _sts.join(); |
| _cm->clearNextBitmap(); |
| _sts.leave(); |
| } |
| |
| // Update the number of full collections that have been |
| // completed. This will also notify the FullGCCount_lock in case a |
| // Java thread is waiting for a full GC to happen (e.g., it |
| // called System.gc() with +ExplicitGCInvokesConcurrent). |
| _sts.join(); |
| g1h->increment_full_collections_completed(true /* concurrent */); |
| _sts.leave(); |
| } |
| assert(_should_terminate, "just checking"); |
| |
| terminate(); |
| } |
| |
| |
| void ConcurrentMarkThread::yield() { |
| _sts.yield("Concurrent Mark"); |
| } |
| |
| 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(); |
| } |
| } |
| |
| void ConcurrentMarkThread::print() const { |
| print_on(tty); |
| } |
| |
| void ConcurrentMarkThread::print_on(outputStream* st) const { |
| st->print("\"G1 Main Concurrent Mark GC Thread\" "); |
| Thread::print_on(st); |
| st->cr(); |
| } |
| |
| void ConcurrentMarkThread::sleepBeforeNextCycle() { |
| // We join here because we don't want to do the "shouldConcurrentMark()" |
| // below while the world is otherwise stopped. |
| assert(!in_progress(), "should have been cleared"); |
| |
| MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag); |
| while (!started()) { |
| CGC_lock->wait(Mutex::_no_safepoint_check_flag); |
| } |
| set_in_progress(); |
| clear_started(); |
| } |
| |
| // 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); |
| } |
