1 /* 2 * Copyright (c) 2001, 2009, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "incls/_precompiled.incl" 26 #include "incls/_vm_operations_g1.cpp.incl" 27 28 void VM_G1CollectForAllocation::doit() { 29 JvmtiGCForAllocationMarker jgcm; 30 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 31 _res = g1h->satisfy_failed_allocation(_size); 32 assert(g1h->is_in_or_null(_res), "result not in heap"); 33 } 34 35 void VM_G1CollectFull::doit() { 36 JvmtiGCFullMarker jgcm; 37 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 38 GCCauseSetter x(g1h, _gc_cause); 39 g1h->do_full_collection(false /* clear_all_soft_refs */); 40 } 41 42 void VM_G1IncCollectionPause::doit() { 43 JvmtiGCForAllocationMarker jgcm; 44 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 45 assert(!_should_initiate_conc_mark || 46 ((_gc_cause == GCCause::_gc_locker && GCLockerInvokesConcurrent) || 47 (_gc_cause == GCCause::_java_lang_system_gc && ExplicitGCInvokesConcurrent)), 48 "only a GC locker or a System.gc() induced GC should start a cycle"); 49 50 GCCauseSetter x(g1h, _gc_cause); 51 if (_should_initiate_conc_mark) { 52 // It's safer to read full_collections_completed() here, given 53 // that noone else will be updating it concurrently. Since we'll 54 // only need it if we're initiating a marking cycle, no point in 55 // setting it earlier. 56 _full_collections_completed_before = g1h->full_collections_completed(); 57 58 // At this point we are supposed to start a concurrent cycle. We 59 // will do so if one is not already in progress. 60 bool res = g1h->g1_policy()->force_initial_mark_if_outside_cycle(); 61 } 62 g1h->do_collection_pause_at_safepoint(_target_pause_time_ms); 63 } 64 65 void VM_G1IncCollectionPause::doit_epilogue() { 66 VM_GC_Operation::doit_epilogue(); 67 68 // If the pause was initiated by a System.gc() and 69 // +ExplicitGCInvokesConcurrent, we have to wait here for the cycle 70 // that just started (or maybe one that was already in progress) to 71 // finish. 72 if (_gc_cause == GCCause::_java_lang_system_gc && 73 _should_initiate_conc_mark) { 74 assert(ExplicitGCInvokesConcurrent, 75 "the only way to be here is if ExplicitGCInvokesConcurrent is set"); 76 77 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 78 79 // In the doit() method we saved g1h->full_collections_completed() 80 // in the _full_collections_completed_before field. We have to 81 // wait until we observe that g1h->full_collections_completed() 82 // has increased by at least one. This can happen if a) we started 83 // a cycle and it completes, b) a cycle already in progress 84 // completes, or c) a Full GC happens. 85 86 // If the condition has already been reached, there's no point in 87 // actually taking the lock and doing the wait. 88 if (g1h->full_collections_completed() <= 89 _full_collections_completed_before) { 90 // The following is largely copied from CMS 91 92 Thread* thr = Thread::current(); 93 assert(thr->is_Java_thread(), "invariant"); 94 JavaThread* jt = (JavaThread*)thr; 95 ThreadToNativeFromVM native(jt); 96 97 MutexLockerEx x(FullGCCount_lock, Mutex::_no_safepoint_check_flag); 98 while (g1h->full_collections_completed() <= 99 _full_collections_completed_before) { 100 FullGCCount_lock->wait(Mutex::_no_safepoint_check_flag); 101 } 102 } 103 } 104 } 105 106 void VM_CGC_Operation::doit() { 107 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps); 108 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); 109 TraceTime t(_printGCMessage, PrintGC, true, gclog_or_tty); 110 SharedHeap* sh = SharedHeap::heap(); 111 // This could go away if CollectedHeap gave access to _gc_is_active... 112 if (sh != NULL) { 113 IsGCActiveMark x; 114 _cl->do_void(); 115 } else { 116 _cl->do_void(); 117 } 118 } 119 120 bool VM_CGC_Operation::doit_prologue() { 121 Heap_lock->lock(); 122 SharedHeap::heap()->_thread_holds_heap_lock_for_gc = true; 123 return true; 124 } 125 126 void VM_CGC_Operation::doit_epilogue() { 127 SharedHeap::heap()->_thread_holds_heap_lock_for_gc = false; 128 Heap_lock->unlock(); 129 }