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8079792: GC directory structure cleanup

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Reviewed-by: brutisso, stefank, david
This commit is contained in:
Per Lidén 2015-05-13 15:16:06 +02:00
parent 042902811c
commit 4dc240f785
521 changed files with 2481 additions and 2573 deletions
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350
hotspot/src/share/vm/gc_implementation/g1/concurrentMarkThread.cpp
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@ -1,350 +0,0 @@
/*
* Copyright (c) 2001, 2015, 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/g1Log.hpp"
#include "gc_implementation/g1/g1MMUTracker.hpp"
#include "gc_implementation/g1/vm_operations_g1.hpp"
#include "gc_implementation/shared/gcTrace.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) {
set_name("G1 Main Marker");
create_and_start();
}
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();
if (_should_terminate) {
break;
}
{
ResourceMark rm;
HandleMark hm;
double cycle_start = os::elapsedVTime();
// We have to ensure that we finish scanning the root regions
// before the next GC takes place. To ensure this we have to
// make sure that we do not join the STS until the root regions
// have been scanned. If we did then it's possible that a
// subsequent GC could block us from joining the STS and proceed
// without the root regions have been scanned which would be a
// correctness issue.
double scan_start = os::elapsedTime();
if (!cm()->has_aborted()) {
if (G1Log::fine()) {
gclog_or_tty->gclog_stamp(cm()->concurrent_gc_id());
gclog_or_tty->print_cr("[GC concurrent-root-region-scan-start]");
}
_cm->scanRootRegions();
double scan_end = os::elapsedTime();
if (G1Log::fine()) {
gclog_or_tty->gclog_stamp(cm()->concurrent_gc_id());
gclog_or_tty->print_cr("[GC concurrent-root-region-scan-end, %1.7lf secs]",
scan_end - scan_start);
}
}
double mark_start_sec = os::elapsedTime();
if (G1Log::fine()) {
gclog_or_tty->gclog_stamp(cm()->concurrent_gc_id());
gclog_or_tty->print_cr("[GC concurrent-mark-start]");
}
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 (G1Log::fine()) {
gclog_or_tty->gclog_stamp(cm()->concurrent_gc_id());
gclog_or_tty->print_cr("[GC concurrent-mark-end, %1.7lf secs]",
mark_end_sec - mark_start_sec);
}
CMCheckpointRootsFinalClosure final_cl(_cm);
VM_CGC_Operation op(&final_cl, "GC remark", true /* needs_pll */);
VMThread::execute(&op);
}
if (cm()->restart_for_overflow()) {
if (G1TraceMarkStackOverflow) {
gclog_or_tty->print_cr("Restarting conc marking because of MS overflow "
"in remark (restart #%d).", iter);
}
if (G1Log::fine()) {
gclog_or_tty->gclog_stamp(cm()->concurrent_gc_id());
gclog_or_tty->print_cr("[GC concurrent-mark-restart-for-overflow]");
}
}
} while (cm()->restart_for_overflow());
double end_time = os::elapsedVTime();
// 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);
VM_CGC_Operation op(&cl_cl, "GC cleanup", false /* needs_pll */);
VMThread::execute(&op);
} else {
// We don't want to update the marking status if a GC pause
// is already underway.
SuspendibleThreadSetJoiner sts_join;
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 place, then we would carry on freeing regions in
// case they are needed by the pause. If a Full GC takes
// place, it would wait for us to process the regions
// reclaimed by cleanup.
double cleanup_start_sec = os::elapsedTime();
if (G1Log::fine()) {
gclog_or_tty->gclog_stamp(cm()->concurrent_gc_id());
gclog_or_tty->print_cr("[GC concurrent-cleanup-start]");
}
// Now do the concurrent cleanup operation.
_cm->completeCleanup();
// Notify anyone who's waiting that there are no more free
// regions coming. We have to do this before we join the STS
// (in fact, we should not attempt to join the STS in the
// interval between finishing the cleanup pause and clearing
// the free_regions_coming flag) otherwise we might deadlock:
// a GC worker could be blocked waiting for the notification
// whereas this thread will be blocked for the pause to finish
// while it's trying to join the STS, which is conditional on
// the GC workers finishing.
g1h->reset_free_regions_coming();
double cleanup_end_sec = os::elapsedTime();
if (G1Log::fine()) {
gclog_or_tty->gclog_stamp(cm()->concurrent_gc_id());
gclog_or_tty->print_cr("[GC concurrent-cleanup-end, %1.7lf secs]",
cleanup_end_sec - cleanup_start_sec);
}
}
guarantee(cm()->cleanup_list_is_empty(),
"at this point there should be no regions on the cleanup list");
// There is a tricky race before recording that the concurrent
// cleanup has completed and a potential Full GC starting around
// the same time. We want to make sure that the Full GC calls
// abort() on concurrent mark after
// record_concurrent_mark_cleanup_completed(), since abort() is
// the method that will reset the concurrent mark state. If we
// end up calling record_concurrent_mark_cleanup_completed()
// after abort() then we might incorrectly undo some of the work
// abort() did. Checking the has_aborted() flag after joining
// the STS allows the correct ordering of the two methods. There
// are two scenarios:
//
// a) If we reach here before the Full GC, the fact that we have
// joined the STS means that the Full GC cannot start until we
// leave the STS, so record_concurrent_mark_cleanup_completed()
// will complete before abort() is called.
//
// b) If we reach here during the Full GC, we'll be held up from
// joining the STS until the Full GC is done, which means that
// abort() will have completed and has_aborted() will return
// true to prevent us from calling
// record_concurrent_mark_cleanup_completed() (and, in fact, it's
// not needed any more as the concurrent mark state has been
// already reset).
{
SuspendibleThreadSetJoiner sts_join;
if (!cm()->has_aborted()) {
g1_policy->record_concurrent_mark_cleanup_completed();
}
}
if (cm()->has_aborted()) {
if (G1Log::fine()) {
gclog_or_tty->gclog_stamp(cm()->concurrent_gc_id());
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.
// We may have aborted just before the remark. Do not bother clearing the
// bitmap then, as it has been done during mark abort.
if (!cm()->has_aborted()) {
_cm->clearNextBitmap();
} else {
assert(!G1VerifyBitmaps || _cm->nextMarkBitmapIsClear(), "Next mark bitmap must be clear");
}
}
// 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).
{
SuspendibleThreadSetJoiner sts_join;
g1h->increment_old_marking_cycles_completed(true /* concurrent */);
g1h->register_concurrent_cycle_end();
}
}
assert(_should_terminate, "just checking");
terminate();
}
void ConcurrentMarkThread::stop() {
{
MutexLockerEx ml(Terminator_lock);
_should_terminate = true;
}
{
MutexLockerEx ml(CGC_lock, Mutex::_no_safepoint_check_flag);
CGC_lock->notify_all();
}
{
MutexLockerEx ml(Terminator_lock);
while (!_has_terminated) {
Terminator_lock->wait();
}
}
}
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() && !_should_terminate) {
CGC_lock->wait(Mutex::_no_safepoint_check_flag);
}
if (started()) {
set_in_progress();
clear_started();
}
}
// Note: As is the case with CMS - this method, although exported
// by the ConcurrentMarkThread, 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 CM thread
// itself to create this thread?
void ConcurrentMarkThread::makeSurrogateLockerThread(TRAPS) {
assert(UseG1GC, "SLT thread needed only for concurrent GC");
assert(THREAD->is_Java_thread(), "must be a Java thread");
assert(_slt == NULL, "SLT already created");
_slt = SurrogateLockerThread::make(THREAD);
}