1 /*
2 * Copyright (c) 2013, 2015, Red Hat, Inc. and/or its affiliates.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #include "gc/shared/gcTraceTime.inline.hpp"
25 #include "gc/shenandoah/shenandoahConcurrentThread.hpp"
26 #include "gc/shenandoah/shenandoahCollectorPolicy.hpp"
27 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
28 #include "gc/shenandoah/shenandoahMonitoringSupport.hpp"
29 #include "gc/shenandoah/vm_operations_shenandoah.hpp"
30 #include "memory/iterator.hpp"
31 #include "memory/universe.hpp"
32 #include "runtime/vmThread.hpp"
33
34 ShenandoahConcurrentThread::ShenandoahConcurrentThread() :
35 ConcurrentGCThread(),
36 _full_gc_lock(Mutex::leaf, "ShenandoahFullGC_lock", true, Monitor::_safepoint_check_always),
37 _do_full_gc(false)
38 {
39 create_and_start();
40 }
41
42 ShenandoahConcurrentThread::~ShenandoahConcurrentThread() {
43 // This is here so that super is called.
44 }
45
46 void ShenandoahConcurrentThread::run_service() {
47
48 while (! ReferencePendingListLocker::is_initialized()) {
49 os::naked_yield();
50 }
51
52 ShenandoahHeap* heap = ShenandoahHeap::heap();
53
54 GCTimer* gc_timer = heap->gc_timer();
55
56 while (! should_terminate()) {
57 if (_do_full_gc) {
58 {
59 if (_full_gc_cause == GCCause::_allocation_failure) {
60 heap->shenandoahPolicy()->record_allocation_failure_gc();
61 } else {
62 heap->shenandoahPolicy()->record_user_requested_gc();
63 }
64
65 TraceCollectorStats tcs(heap->monitoring_support()->full_collection_counters());
66 TraceMemoryManagerStats tmms(true, _full_gc_cause);
67 VM_ShenandoahFullGC full_gc(_full_gc_cause);
68 VMThread::execute(&full_gc);
69 }
70 MonitorLockerEx ml(&_full_gc_lock);
71 _do_full_gc = false;
72 ml.notify_all();
73 } else if (heap->shenandoahPolicy()->should_start_concurrent_mark(heap->used(),
74 heap->capacity()))
75 {
76
77 gc_timer->register_gc_start();
78
79 heap->shenandoahPolicy()->increase_cycle_counter();
80
81 TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters());
82 TraceMemoryManagerStats tmms(false, GCCause::_no_cause_specified);
83
84 {
85 TraceCollectorStats tcs(heap->monitoring_support()->stw_collection_counters());
86 VM_ShenandoahInitMark initMark;
87 heap->shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::init_mark_gross);
88 VMThread::execute(&initMark);
89 heap->shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::init_mark_gross);
90 }
91 {
92 GCTraceTime(Info, gc) time("Concurrent marking", gc_timer, GCCause::_no_gc, true);
93 TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters());
94 ShenandoahHeap::heap()->concurrentMark()->mark_from_roots();
95 }
96
97 {
98 TraceCollectorStats tcs(heap->monitoring_support()->stw_collection_counters());
99 VM_ShenandoahStartEvacuation finishMark;
100 heap->shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::final_mark_gross);
101 VMThread::execute(&finishMark);
102 heap->shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::final_mark_gross);
103 }
104
105 if (! should_terminate()) {
106 GCTraceTime(Info, gc) time("Concurrent evacuation ", gc_timer, GCCause::_no_gc, true);
107 TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters());
108 heap->do_evacuation();
109 }
110
111 if (heap->is_evacuation_in_progress()) {
112 MutexLocker mu(Threads_lock);
113 heap->set_evacuation_in_progress(false);
114 }
115 heap->shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::reset_bitmaps);
116 heap->reset_mark_bitmap();
117 heap->shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::reset_bitmaps);
118
119 gc_timer->register_gc_end();
120 } else {
121 Thread::current()->_ParkEvent->park(10) ;
122 // yield();
123 }
124
125 // Make sure the _do_full_gc flag changes are seen.
126 OrderAccess::storeload();
127 }
128 }
129
130 void ShenandoahConcurrentThread::stop_service() {
131 // Nothing to do here.
132 }
133
134 void ShenandoahConcurrentThread::do_full_gc(GCCause::Cause cause) {
135
136 assert(Thread::current()->is_Java_thread(), "expect Java thread here");
137
138 MonitorLockerEx ml(&_full_gc_lock);
139 schedule_full_gc();
140 _full_gc_cause = cause;
141 while (_do_full_gc) {
142 ml.wait();
143 OrderAccess::storeload();
144 }
145 assert(_do_full_gc == false, "expect full GC to have completed");
146 }
147
148 void ShenandoahConcurrentThread::schedule_full_gc() {
149 _do_full_gc = true;
150 }
151
152 void ShenandoahConcurrentThread::print() const {
153 print_on(tty);
154 }
155
156 void ShenandoahConcurrentThread::print_on(outputStream* st) const {
157 st->print("Shenandoah Concurrent Thread");
158 Thread::print_on(st);
159 st->cr();
160 }
161
162 void ShenandoahConcurrentThread::sleepBeforeNextCycle() {
163 assert(false, "Wake up in the GC thread that never sleeps :-)");
164 }
165
166 void ShenandoahConcurrentThread::start() {
167 create_and_start();
168 }