src/share/vm/gc_implementation/g1/vm_operations_g1.cpp

Mon, 02 Aug 2010 12:51:43 -0700

author
johnc
date
Mon, 02 Aug 2010 12:51:43 -0700
changeset 2060
2d160770d2e5
parent 2011
4e5661ba9d98
child 2314
f95d63e2154a
permissions
-rw-r--r--

6814437: G1: remove the _new_refs array
Summary: The per-worker _new_refs array is used to hold references that point into the collection set. It is populated during RSet updating and subsequently processed. In the event of an evacuation failure it processed again to recreate the RSets of regions in the collection set. Remove the per-worker _new_refs array by processing the references directly. Use a DirtyCardQueue to hold the cards containing the references so that the RSets of regions in the collection set can be recreated when handling an evacuation failure.
Reviewed-by: iveresov, jmasa, tonyp

ysr@777 1 /*
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ysr@777 5 * This code is free software; you can redistribute it and/or modify it
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ysr@777 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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ysr@777 23 */
ysr@777 24
ysr@777 25 #include "incls/_precompiled.incl"
ysr@777 26 #include "incls/_vm_operations_g1.cpp.incl"
ysr@777 27
ysr@777 28 void VM_G1CollectForAllocation::doit() {
ysr@777 29 JvmtiGCForAllocationMarker jgcm;
ysr@777 30 G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777 31 _res = g1h->satisfy_failed_allocation(_size);
ysr@777 32 assert(g1h->is_in_or_null(_res), "result not in heap");
ysr@777 33 }
ysr@777 34
ysr@777 35 void VM_G1CollectFull::doit() {
ysr@777 36 JvmtiGCFullMarker jgcm;
ysr@777 37 G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777 38 GCCauseSetter x(g1h, _gc_cause);
ysr@777 39 g1h->do_full_collection(false /* clear_all_soft_refs */);
ysr@777 40 }
ysr@777 41
ysr@777 42 void VM_G1IncCollectionPause::doit() {
ysr@777 43 JvmtiGCForAllocationMarker jgcm;
ysr@777 44 G1CollectedHeap* g1h = G1CollectedHeap::heap();
tonyp@2011 45 assert(!_should_initiate_conc_mark ||
tonyp@2011 46 ((_gc_cause == GCCause::_gc_locker && GCLockerInvokesConcurrent) ||
tonyp@2011 47 (_gc_cause == GCCause::_java_lang_system_gc && ExplicitGCInvokesConcurrent)),
tonyp@2011 48 "only a GC locker or a System.gc() induced GC should start a cycle");
tonyp@2011 49
ysr@1523 50 GCCauseSetter x(g1h, _gc_cause);
tonyp@2011 51 if (_should_initiate_conc_mark) {
tonyp@2011 52 // It's safer to read full_collections_completed() here, given
tonyp@2011 53 // that noone else will be updating it concurrently. Since we'll
tonyp@2011 54 // only need it if we're initiating a marking cycle, no point in
tonyp@2011 55 // setting it earlier.
tonyp@2011 56 _full_collections_completed_before = g1h->full_collections_completed();
tonyp@2011 57
tonyp@2011 58 // At this point we are supposed to start a concurrent cycle. We
tonyp@2011 59 // will do so if one is not already in progress.
tonyp@2011 60 bool res = g1h->g1_policy()->force_initial_mark_if_outside_cycle();
tonyp@2011 61 }
tonyp@2011 62 g1h->do_collection_pause_at_safepoint(_target_pause_time_ms);
tonyp@2011 63 }
tonyp@2011 64
tonyp@2011 65 void VM_G1IncCollectionPause::doit_epilogue() {
tonyp@2011 66 VM_GC_Operation::doit_epilogue();
tonyp@2011 67
tonyp@2011 68 // If the pause was initiated by a System.gc() and
tonyp@2011 69 // +ExplicitGCInvokesConcurrent, we have to wait here for the cycle
tonyp@2011 70 // that just started (or maybe one that was already in progress) to
tonyp@2011 71 // finish.
tonyp@2011 72 if (_gc_cause == GCCause::_java_lang_system_gc &&
tonyp@2011 73 _should_initiate_conc_mark) {
tonyp@2011 74 assert(ExplicitGCInvokesConcurrent,
tonyp@2011 75 "the only way to be here is if ExplicitGCInvokesConcurrent is set");
tonyp@2011 76
tonyp@2011 77 G1CollectedHeap* g1h = G1CollectedHeap::heap();
tonyp@2011 78
tonyp@2011 79 // In the doit() method we saved g1h->full_collections_completed()
tonyp@2011 80 // in the _full_collections_completed_before field. We have to
tonyp@2011 81 // wait until we observe that g1h->full_collections_completed()
tonyp@2011 82 // has increased by at least one. This can happen if a) we started
tonyp@2011 83 // a cycle and it completes, b) a cycle already in progress
tonyp@2011 84 // completes, or c) a Full GC happens.
tonyp@2011 85
tonyp@2011 86 // If the condition has already been reached, there's no point in
tonyp@2011 87 // actually taking the lock and doing the wait.
tonyp@2011 88 if (g1h->full_collections_completed() <=
tonyp@2011 89 _full_collections_completed_before) {
tonyp@2011 90 // The following is largely copied from CMS
tonyp@2011 91
tonyp@2011 92 Thread* thr = Thread::current();
tonyp@2011 93 assert(thr->is_Java_thread(), "invariant");
tonyp@2011 94 JavaThread* jt = (JavaThread*)thr;
tonyp@2011 95 ThreadToNativeFromVM native(jt);
tonyp@2011 96
tonyp@2011 97 MutexLockerEx x(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
tonyp@2011 98 while (g1h->full_collections_completed() <=
tonyp@2011 99 _full_collections_completed_before) {
tonyp@2011 100 FullGCCount_lock->wait(Mutex::_no_safepoint_check_flag);
tonyp@2011 101 }
tonyp@2011 102 }
tonyp@2011 103 }
ysr@777 104 }
ysr@777 105
ysr@777 106 void VM_CGC_Operation::doit() {
ysr@777 107 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
ysr@777 108 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
ysr@777 109 TraceTime t(_printGCMessage, PrintGC, true, gclog_or_tty);
ysr@777 110 SharedHeap* sh = SharedHeap::heap();
ysr@777 111 // This could go away if CollectedHeap gave access to _gc_is_active...
ysr@777 112 if (sh != NULL) {
ysr@777 113 IsGCActiveMark x;
ysr@777 114 _cl->do_void();
ysr@777 115 } else {
ysr@777 116 _cl->do_void();
ysr@777 117 }
ysr@777 118 }
ysr@777 119
ysr@777 120 bool VM_CGC_Operation::doit_prologue() {
ysr@777 121 Heap_lock->lock();
ysr@777 122 SharedHeap::heap()->_thread_holds_heap_lock_for_gc = true;
ysr@777 123 return true;
ysr@777 124 }
ysr@777 125
ysr@777 126 void VM_CGC_Operation::doit_epilogue() {
ysr@777 127 SharedHeap::heap()->_thread_holds_heap_lock_for_gc = false;
ysr@777 128 Heap_lock->unlock();
ysr@777 129 }

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