Thu, 21 Aug 2014 16:44:41 +0200
8055098: WB API should be extended to provide information about size and age of object.
Summary: Extend the WhiteBox API to provide information about the size and age of objects. Further add a mechanism to trigger a young GC.
Reviewed-by: tschatzl, sjohanss
Contributed-by: Leonid Mesnik <leonid.mesnik@oracle.com>
1 /*
2 * Copyright (c) 2014, 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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP
28 #include "gc_implementation/g1/dirtyCardQueue.hpp"
29 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
30 #include "gc_implementation/g1/g1CollectedHeap.hpp"
31 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
32 #include "gc_implementation/g1/g1OopClosures.hpp"
33 #include "gc_implementation/g1/g1RemSet.hpp"
34 #include "gc_implementation/shared/ageTable.hpp"
35 #include "memory/allocation.hpp"
36 #include "oops/oop.hpp"
38 class HeapRegion;
39 class outputStream;
41 class G1ParScanThreadState : public StackObj {
42 private:
43 G1CollectedHeap* _g1h;
44 RefToScanQueue* _refs;
45 DirtyCardQueue _dcq;
46 G1SATBCardTableModRefBS* _ct_bs;
47 G1RemSet* _g1_rem;
49 G1ParGCAllocBuffer _surviving_alloc_buffer;
50 G1ParGCAllocBuffer _tenured_alloc_buffer;
51 G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount];
52 ageTable _age_table;
54 G1ParScanClosure _scanner;
56 size_t _alloc_buffer_waste;
57 size_t _undo_waste;
59 OopsInHeapRegionClosure* _evac_failure_cl;
61 int _hash_seed;
62 uint _queue_num;
64 size_t _term_attempts;
66 double _start;
67 double _start_strong_roots;
68 double _strong_roots_time;
69 double _start_term;
70 double _term_time;
72 // Map from young-age-index (0 == not young, 1 is youngest) to
73 // surviving words. base is what we get back from the malloc call
74 size_t* _surviving_young_words_base;
75 // this points into the array, as we use the first few entries for padding
76 size_t* _surviving_young_words;
78 #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))
80 void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; }
82 void add_to_undo_waste(size_t waste) { _undo_waste += waste; }
84 DirtyCardQueue& dirty_card_queue() { return _dcq; }
85 G1SATBCardTableModRefBS* ctbs() { return _ct_bs; }
87 template <class T> inline void immediate_rs_update(HeapRegion* from, T* p, int tid);
89 template <class T> void deferred_rs_update(HeapRegion* from, T* p, int tid) {
90 // If the new value of the field points to the same region or
91 // is the to-space, we don't need to include it in the Rset updates.
92 if (!from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) && !from->is_survivor()) {
93 size_t card_index = ctbs()->index_for(p);
94 // If the card hasn't been added to the buffer, do it.
95 if (ctbs()->mark_card_deferred(card_index)) {
96 dirty_card_queue().enqueue((jbyte*)ctbs()->byte_for_index(card_index));
97 }
98 }
99 }
101 public:
102 G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp);
103 ~G1ParScanThreadState();
105 ageTable* age_table() { return &_age_table; }
107 G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) {
108 return _alloc_buffers[purpose];
109 }
111 size_t alloc_buffer_waste() const { return _alloc_buffer_waste; }
112 size_t undo_waste() const { return _undo_waste; }
114 #ifdef ASSERT
115 bool queue_is_empty() const { return _refs->is_empty(); }
117 bool verify_ref(narrowOop* ref) const;
118 bool verify_ref(oop* ref) const;
119 bool verify_task(StarTask ref) const;
120 #endif // ASSERT
122 template <class T> void push_on_queue(T* ref) {
123 assert(verify_ref(ref), "sanity");
124 _refs->push(ref);
125 }
127 template <class T> inline void update_rs(HeapRegion* from, T* p, int tid);
129 private:
131 inline HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz);
132 inline HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz);
133 inline void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz);
135 public:
137 void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) {
138 _evac_failure_cl = evac_failure_cl;
139 }
141 OopsInHeapRegionClosure* evac_failure_closure() { return _evac_failure_cl; }
143 int* hash_seed() { return &_hash_seed; }
144 uint queue_num() { return _queue_num; }
146 size_t term_attempts() const { return _term_attempts; }
147 void note_term_attempt() { _term_attempts++; }
149 void start_strong_roots() {
150 _start_strong_roots = os::elapsedTime();
151 }
152 void end_strong_roots() {
153 _strong_roots_time += (os::elapsedTime() - _start_strong_roots);
154 }
155 double strong_roots_time() const { return _strong_roots_time; }
157 void start_term_time() {
158 note_term_attempt();
159 _start_term = os::elapsedTime();
160 }
161 void end_term_time() {
162 _term_time += (os::elapsedTime() - _start_term);
163 }
164 double term_time() const { return _term_time; }
166 double elapsed_time() const {
167 return os::elapsedTime() - _start;
168 }
170 static void print_termination_stats_hdr(outputStream* const st = gclog_or_tty);
171 void print_termination_stats(int i, outputStream* const st = gclog_or_tty) const;
173 size_t* surviving_young_words() {
174 // We add on to hide entry 0 which accumulates surviving words for
175 // age -1 regions (i.e. non-young ones)
176 return _surviving_young_words;
177 }
179 private:
180 void retire_alloc_buffers();
182 #define G1_PARTIAL_ARRAY_MASK 0x2
184 inline bool has_partial_array_mask(oop* ref) const {
185 return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
186 }
188 // We never encode partial array oops as narrowOop*, so return false immediately.
189 // This allows the compiler to create optimized code when popping references from
190 // the work queue.
191 inline bool has_partial_array_mask(narrowOop* ref) const {
192 assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
193 return false;
194 }
196 // Only implement set_partial_array_mask() for regular oops, not for narrowOops.
197 // We always encode partial arrays as regular oop, to allow the
198 // specialization for has_partial_array_mask() for narrowOops above.
199 // This means that unintentional use of this method with narrowOops are caught
200 // by the compiler.
201 inline oop* set_partial_array_mask(oop obj) const {
202 assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
203 return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
204 }
206 inline oop clear_partial_array_mask(oop* ref) const {
207 return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
208 }
210 inline void do_oop_partial_array(oop* p);
212 // This method is applied to the fields of the objects that have just been copied.
213 template <class T> inline void do_oop_evac(T* p, HeapRegion* from);
215 template <class T> inline void deal_with_reference(T* ref_to_scan);
217 inline void dispatch_reference(StarTask ref);
218 public:
220 oop copy_to_survivor_space(oop const obj);
222 void trim_queue();
224 inline void steal_and_trim_queue(RefToScanQueueSet *task_queues);
225 };
227 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP