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/shenandoahJNICritical.hpp"
29 #include "gc/shenandoah/shenandoahMonitoringSupport.hpp"
30 #include "gc/shenandoah/vm_operations_shenandoah.hpp"
31 #include "memory/iterator.hpp"
32 #include "memory/universe.hpp"
33 #include "runtime/vmThread.hpp"
34
35 ShenandoahConcurrentThread::ShenandoahConcurrentThread() :
36 ConcurrentGCThread(),
37 _full_gc_lock(Mutex::leaf, "ShenandoahFullGC_lock", true, Monitor::_safepoint_check_always),
38 _do_full_gc(false)
39 {
40 create_and_start();
41 }
42
43 ShenandoahConcurrentThread::~ShenandoahConcurrentThread() {
44 // This is here so that super is called.
45 }
46
47 void ShenandoahConcurrentThread::run_service() {
48
49 while (! ReferencePendingListLocker::is_initialized()) {
50 os::naked_yield();
51 }
52
53 ShenandoahHeap* heap = ShenandoahHeap::heap();
54
55 GCTimer* gc_timer = heap->gc_timer();
56
57 while (! should_terminate()) {
58 if (_do_full_gc) {
59 {
60 if (_full_gc_cause == GCCause::_allocation_failure) {
61 heap->shenandoahPolicy()->record_allocation_failure_gc();
62 } else {
63 heap->shenandoahPolicy()->record_user_requested_gc();
64 }
65
66 TraceCollectorStats tcs(heap->monitoring_support()->full_collection_counters());
67 TraceMemoryManagerStats tmms(true, _full_gc_cause);
68 VM_ShenandoahFullGC full_gc(_full_gc_cause);
69 heap->jni_critical()->execute_in_vm_thread(&full_gc);
70 }
71 MonitorLockerEx ml(&_full_gc_lock);
72 _do_full_gc = false;
73 ml.notify_all();
74 } else if (heap->shenandoahPolicy()->should_start_concurrent_mark(heap->used(),
75 heap->capacity()))
76 {
77
78 gc_timer->register_gc_start();
79
80 heap->shenandoahPolicy()->increase_cycle_counter();
81
82 TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters());
83 TraceMemoryManagerStats tmms(false, GCCause::_no_cause_specified);
84 if (ShenandoahGCVerbose)
85 tty->print("Capacity = "SIZE_FORMAT" Used = "SIZE_FORMAT" doing initMark\n", heap->capacity(), heap->used());
86
87 if (ShenandoahGCVerbose) tty->print("Starting a mark");
88
89 {
90 TraceCollectorStats tcs(heap->monitoring_support()->stw_collection_counters());
91 VM_ShenandoahInitMark initMark;
92 heap->shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::init_mark_gross);
93 VMThread::execute(&initMark);
94 heap->shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::init_mark_gross);
95 }
96 {
97 GCTraceTime(Info, gc, phases) time("Concurrent marking", gc_timer, GCCause::_no_gc, true);
98 TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters());
99 ShenandoahHeap::heap()->concurrentMark()->mark_from_roots();
100 }
101
102 {
103 TraceCollectorStats tcs(heap->monitoring_support()->stw_collection_counters());
104 VM_ShenandoahStartEvacuation finishMark;
105 heap->shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::final_mark_gross);
106 heap->jni_critical()->execute_in_vm_thread(&finishMark);
107 heap->shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::final_mark_gross);
108 }
109
110 if (! should_terminate()) {
111 GCTraceTime(Info, gc, phases) time("Concurrent evacuation", gc_timer, GCCause::_no_gc, true);
112 TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters());
113 heap->do_evacuation();
114 }
115
116 if (heap->is_evacuation_in_progress()) {
117 heap->set_evacuation_in_progress(false);
118 }
119 heap->shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::reset_bitmaps);
120 heap->reset_mark_bitmap();
121 heap->shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::reset_bitmaps);
122
123 gc_timer->register_gc_end();
124 } else {
125 Thread::current()->_ParkEvent->park(10) ;
126 // yield();
127 }
128
129 // Make sure the _do_full_gc flag changes are seen.
130 OrderAccess::storeload();
131 }
132 }
133
134 void ShenandoahConcurrentThread::stop_service() {
135 // Nothing to do here.
136 }
137
138 void ShenandoahConcurrentThread::do_full_gc(GCCause::Cause cause) {
139
140 assert(Thread::current()->is_Java_thread(), "expect Java thread here");
141
142 MonitorLockerEx ml(&_full_gc_lock);
143 schedule_full_gc();
144 _full_gc_cause = cause;
145 while (_do_full_gc) {
146 ml.wait();
147 OrderAccess::storeload();
148 }
149 assert(_do_full_gc == false, "expect full GC to have completed");
150 }
151
152 void ShenandoahConcurrentThread::schedule_full_gc() {
153 _do_full_gc = true;
154 }
155
156 void ShenandoahConcurrentThread::print() const {
157 print_on(tty);
158 }
159
160 void ShenandoahConcurrentThread::print_on(outputStream* st) const {
161 st->print("Shenandoah Concurrent Thread");
162 Thread::print_on(st);
163 st->cr();
164 }
165
166 void ShenandoahConcurrentThread::sleepBeforeNextCycle() {
167 assert(false, "Wake up in the GC thread that never sleeps :-)");
168 }
169
170 void ShenandoahConcurrentThread::start() {
171 create_and_start();
172 }