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 if (ShenandoahGCVerbose) 84 tty->print("Capacity = "SIZE_FORMAT" Used = "SIZE_FORMAT" doing initMark\n", heap->capacity(), heap->used()); 85 86 if (ShenandoahGCVerbose) tty->print("Starting a mark"); 87 88 { 89 TraceCollectorStats tcs(heap->monitoring_support()->stw_collection_counters()); 90 VM_ShenandoahInitMark initMark; 91 heap->shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::init_mark_gross); 92 VMThread::execute(&initMark); 93 heap->shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::init_mark_gross); 94 } 95 { 96 GCTraceTime(Info, gc, phases) time("Concurrent marking", gc_timer, GCCause::_no_gc, true); 97 TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters()); 98 ShenandoahHeap::heap()->concurrentMark()->mark_from_roots(); 99 } 100 101 { 102 TraceCollectorStats tcs(heap->monitoring_support()->stw_collection_counters()); 103 VM_ShenandoahStartEvacuation finishMark; 104 heap->shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::final_mark_gross); 105 VMThread::execute(&finishMark); 106 heap->shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::final_mark_gross); 107 } 108 109 if (! should_terminate()) { 110 GCTraceTime(Info, gc, phases) time("Concurrent evacuation", gc_timer, GCCause::_no_gc, true); 111 TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters()); 112 heap->do_evacuation(); 113 } 114 115 if (heap->is_evacuation_in_progress()) { 116 heap->set_evacuation_in_progress(false); 117 } 118 heap->shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::reset_bitmaps); 119 heap->reset_mark_bitmap(); 120 heap->shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::reset_bitmaps); 121 122 gc_timer->register_gc_end(); 123 } else { 124 Thread::current()->_ParkEvent->park(10) ; 125 // yield(); 126 } 127 128 // Make sure the _do_full_gc flag changes are seen. 129 OrderAccess::storeload(); 130 } 131 } 132 133 void ShenandoahConcurrentThread::stop_service() { 134 // Nothing to do here. 135 } 136 137 void ShenandoahConcurrentThread::do_full_gc(GCCause::Cause cause) { 138 139 assert(Thread::current()->is_Java_thread(), "expect Java thread here"); 140 141 MonitorLockerEx ml(&_full_gc_lock); 142 schedule_full_gc(); 143 _full_gc_cause = cause; 144 while (_do_full_gc) { 145 ml.wait(); 146 OrderAccess::storeload(); 147 } 148 assert(_do_full_gc == false, "expect full GC to have completed"); 149 } 150 151 void ShenandoahConcurrentThread::schedule_full_gc() { 152 _do_full_gc = true; 153 } 154 155 void ShenandoahConcurrentThread::print() const { 156 print_on(tty); 157 } 158 159 void ShenandoahConcurrentThread::print_on(outputStream* st) const { 160 st->print("Shenandoah Concurrent Thread"); 161 Thread::print_on(st); 162 st->cr(); 163 } 164 165 void ShenandoahConcurrentThread::sleepBeforeNextCycle() { 166 assert(false, "Wake up in the GC thread that never sleeps :-)"); 167 } 168 169 void ShenandoahConcurrentThread::start() { 170 create_and_start(); 171 }