Tue, 13 Apr 2010 13:52:10 -0700
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
Summary: Ensure a full GC that clears SoftReferences before throwing an out-of-memory
Reviewed-by: ysr, jcoomes
ysr@777 | 1 | /* |
ysr@777 | 2 | * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. |
ysr@777 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
ysr@777 | 4 | * |
ysr@777 | 5 | * This code is free software; you can redistribute it and/or modify it |
ysr@777 | 6 | * under the terms of the GNU General Public License version 2 only, as |
ysr@777 | 7 | * published by the Free Software Foundation. |
ysr@777 | 8 | * |
ysr@777 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
ysr@777 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
ysr@777 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
ysr@777 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
ysr@777 | 13 | * accompanied this code). |
ysr@777 | 14 | * |
ysr@777 | 15 | * You should have received a copy of the GNU General Public License version |
ysr@777 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
ysr@777 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
ysr@777 | 18 | * |
ysr@777 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
ysr@777 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
ysr@777 | 21 | * have any questions. |
ysr@777 | 22 | * |
ysr@777 | 23 | */ |
ysr@777 | 24 | |
ysr@777 | 25 | #ifndef SERIALGC |
ysr@777 | 26 | |
ysr@777 | 27 | class DirtyCardQueueSet; |
ysr@777 | 28 | |
ysr@777 | 29 | // This barrier is specialized to use a logging barrier to support |
ysr@777 | 30 | // snapshot-at-the-beginning marking. |
ysr@777 | 31 | |
ysr@777 | 32 | class G1SATBCardTableModRefBS: public CardTableModRefBSForCTRS { |
ysr@777 | 33 | private: |
ysr@777 | 34 | // Add "pre_val" to a set of objects that may have been disconnected from the |
ysr@777 | 35 | // pre-marking object graph. |
ysr@777 | 36 | static void enqueue(oop pre_val); |
ysr@777 | 37 | |
ysr@777 | 38 | public: |
ysr@777 | 39 | G1SATBCardTableModRefBS(MemRegion whole_heap, |
ysr@777 | 40 | int max_covered_regions); |
ysr@777 | 41 | |
ysr@777 | 42 | bool is_a(BarrierSet::Name bsn) { |
ysr@777 | 43 | return bsn == BarrierSet::G1SATBCT || CardTableModRefBS::is_a(bsn); |
ysr@777 | 44 | } |
ysr@777 | 45 | |
ysr@777 | 46 | virtual bool has_write_ref_pre_barrier() { return true; } |
ysr@777 | 47 | |
ysr@777 | 48 | // This notes that we don't need to access any BarrierSet data |
ysr@777 | 49 | // structures, so this can be called from a static context. |
ysr@1280 | 50 | template <class T> static void write_ref_field_pre_static(T* field, oop newVal) { |
ysr@1280 | 51 | T heap_oop = oopDesc::load_heap_oop(field); |
ysr@1280 | 52 | if (!oopDesc::is_null(heap_oop)) { |
ysr@1280 | 53 | enqueue(oopDesc::decode_heap_oop(heap_oop)); |
ysr@777 | 54 | } |
ysr@777 | 55 | } |
ysr@777 | 56 | |
ysr@777 | 57 | // When we know the current java thread: |
ysr@1280 | 58 | template <class T> static void write_ref_field_pre_static(T* field, oop newVal, |
ysr@1280 | 59 | JavaThread* jt); |
ysr@777 | 60 | |
ysr@777 | 61 | // We export this to make it available in cases where the static |
ysr@777 | 62 | // type of the barrier set is known. Note that it is non-virtual. |
ysr@1280 | 63 | template <class T> inline void inline_write_ref_field_pre(T* field, oop newVal) { |
ysr@777 | 64 | write_ref_field_pre_static(field, newVal); |
ysr@777 | 65 | } |
ysr@777 | 66 | |
ysr@1280 | 67 | // These are the more general virtual versions. |
ysr@1280 | 68 | virtual void write_ref_field_pre_work(oop* field, oop new_val) { |
ysr@777 | 69 | inline_write_ref_field_pre(field, new_val); |
ysr@777 | 70 | } |
ysr@1280 | 71 | virtual void write_ref_field_pre_work(narrowOop* field, oop new_val) { |
ysr@1280 | 72 | inline_write_ref_field_pre(field, new_val); |
ysr@1280 | 73 | } |
ysr@1280 | 74 | virtual void write_ref_field_pre_work(void* field, oop new_val) { |
ysr@1280 | 75 | guarantee(false, "Not needed"); |
ysr@1280 | 76 | } |
ysr@777 | 77 | |
ysr@1280 | 78 | template <class T> void write_ref_array_pre_work(T* dst, int count); |
ysr@1280 | 79 | virtual void write_ref_array_pre(oop* dst, int count) { |
ysr@1280 | 80 | write_ref_array_pre_work(dst, count); |
ysr@1280 | 81 | } |
ysr@1280 | 82 | virtual void write_ref_array_pre(narrowOop* dst, int count) { |
ysr@1280 | 83 | write_ref_array_pre_work(dst, count); |
ysr@1280 | 84 | } |
ysr@777 | 85 | }; |
ysr@777 | 86 | |
ysr@777 | 87 | // Adds card-table logging to the post-barrier. |
ysr@777 | 88 | // Usual invariant: all dirty cards are logged in the DirtyCardQueueSet. |
ysr@777 | 89 | class G1SATBCardTableLoggingModRefBS: public G1SATBCardTableModRefBS { |
ysr@777 | 90 | private: |
ysr@777 | 91 | DirtyCardQueueSet& _dcqs; |
ysr@777 | 92 | public: |
ysr@777 | 93 | G1SATBCardTableLoggingModRefBS(MemRegion whole_heap, |
ysr@777 | 94 | int max_covered_regions); |
ysr@777 | 95 | |
ysr@777 | 96 | bool is_a(BarrierSet::Name bsn) { |
ysr@777 | 97 | return bsn == BarrierSet::G1SATBCTLogging || |
ysr@777 | 98 | G1SATBCardTableModRefBS::is_a(bsn); |
ysr@777 | 99 | } |
ysr@777 | 100 | |
ysr@777 | 101 | void write_ref_field_work(void* field, oop new_val); |
ysr@777 | 102 | |
ysr@777 | 103 | // Can be called from static contexts. |
ysr@777 | 104 | static void write_ref_field_static(void* field, oop new_val); |
ysr@777 | 105 | |
ysr@777 | 106 | // NB: if you do a whole-heap invalidation, the "usual invariant" defined |
ysr@777 | 107 | // above no longer applies. |
ysr@777 | 108 | void invalidate(MemRegion mr, bool whole_heap = false); |
ysr@777 | 109 | |
ysr@777 | 110 | void write_region_work(MemRegion mr) { invalidate(mr); } |
ysr@777 | 111 | void write_ref_array_work(MemRegion mr) { invalidate(mr); } |
ysr@777 | 112 | |
ysr@777 | 113 | |
ysr@777 | 114 | }; |
ysr@777 | 115 | |
ysr@777 | 116 | |
ysr@777 | 117 | #endif // SERIALGC |