Fri, 19 Dec 2014 09:21:06 +0100
8060025: Object copy time regressions after JDK-8031323 and JDK-8057536
Summary: Evaluate and improve object copy time by micro-optimizations and splitting out slow and fast paths aggressively.
Reviewed-by: kbarrett, mgerdin, jmasa
Contributed-by: Tony Printezis <tprintezis@twitter.com>, Thomas Schatzl <thomas.schatzl@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.
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.
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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 G1ParGCAllocator* _g1_par_allocator;
51 ageTable _age_table;
52 InCSetState _dest[InCSetState::Num];
53 // Local tenuring threshold.
54 uint _tenuring_threshold;
55 G1ParScanClosure _scanner;
57 size_t _alloc_buffer_waste;
58 size_t _undo_waste;
60 OopsInHeapRegionClosure* _evac_failure_cl;
62 int _hash_seed;
63 uint _queue_num;
65 size_t _term_attempts;
67 double _start;
68 double _start_strong_roots;
69 double _strong_roots_time;
70 double _start_term;
71 double _term_time;
73 // Map from young-age-index (0 == not young, 1 is youngest) to
74 // surviving words. base is what we get back from the malloc call
75 size_t* _surviving_young_words_base;
76 // this points into the array, as we use the first few entries for padding
77 size_t* _surviving_young_words;
79 #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))
81 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 InCSetState dest(InCSetState original) const {
88 assert(original.is_valid(),
89 err_msg("Original state invalid: " CSETSTATE_FORMAT, original.value()));
90 assert(_dest[original.value()].is_valid_gen(),
91 err_msg("Dest state is invalid: " CSETSTATE_FORMAT, _dest[original.value()].value()));
92 return _dest[original.value()];
93 }
95 public:
96 G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp);
97 ~G1ParScanThreadState();
99 ageTable* age_table() { return &_age_table; }
101 #ifdef ASSERT
102 bool queue_is_empty() const { return _refs->is_empty(); }
104 bool verify_ref(narrowOop* ref) const;
105 bool verify_ref(oop* ref) const;
106 bool verify_task(StarTask ref) const;
107 #endif // ASSERT
109 template <class T> void push_on_queue(T* ref) {
110 assert(verify_ref(ref), "sanity");
111 _refs->push(ref);
112 }
114 template <class T> void update_rs(HeapRegion* from, T* p, int tid) {
115 // If the new value of the field points to the same region or
116 // is the to-space, we don't need to include it in the Rset updates.
117 if (!from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) && !from->is_survivor()) {
118 size_t card_index = ctbs()->index_for(p);
119 // If the card hasn't been added to the buffer, do it.
120 if (ctbs()->mark_card_deferred(card_index)) {
121 dirty_card_queue().enqueue((jbyte*)ctbs()->byte_for_index(card_index));
122 }
123 }
124 }
126 void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) {
127 _evac_failure_cl = evac_failure_cl;
128 }
130 OopsInHeapRegionClosure* evac_failure_closure() { return _evac_failure_cl; }
132 int* hash_seed() { return &_hash_seed; }
133 uint queue_num() { return _queue_num; }
135 size_t term_attempts() const { return _term_attempts; }
136 void note_term_attempt() { _term_attempts++; }
138 void start_strong_roots() {
139 _start_strong_roots = os::elapsedTime();
140 }
141 void end_strong_roots() {
142 _strong_roots_time += (os::elapsedTime() - _start_strong_roots);
143 }
144 double strong_roots_time() const { return _strong_roots_time; }
146 void start_term_time() {
147 note_term_attempt();
148 _start_term = os::elapsedTime();
149 }
150 void end_term_time() {
151 _term_time += (os::elapsedTime() - _start_term);
152 }
153 double term_time() const { return _term_time; }
155 double elapsed_time() const {
156 return os::elapsedTime() - _start;
157 }
159 static void print_termination_stats_hdr(outputStream* const st = gclog_or_tty);
160 void print_termination_stats(int i, outputStream* const st = gclog_or_tty) const;
162 size_t* surviving_young_words() {
163 // We add on to hide entry 0 which accumulates surviving words for
164 // age -1 regions (i.e. non-young ones)
165 return _surviving_young_words;
166 }
168 private:
169 #define G1_PARTIAL_ARRAY_MASK 0x2
171 inline bool has_partial_array_mask(oop* ref) const {
172 return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
173 }
175 // We never encode partial array oops as narrowOop*, so return false immediately.
176 // This allows the compiler to create optimized code when popping references from
177 // the work queue.
178 inline bool has_partial_array_mask(narrowOop* ref) const {
179 assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
180 return false;
181 }
183 // Only implement set_partial_array_mask() for regular oops, not for narrowOops.
184 // We always encode partial arrays as regular oop, to allow the
185 // specialization for has_partial_array_mask() for narrowOops above.
186 // This means that unintentional use of this method with narrowOops are caught
187 // by the compiler.
188 inline oop* set_partial_array_mask(oop obj) const {
189 assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
190 return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
191 }
193 inline oop clear_partial_array_mask(oop* ref) const {
194 return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
195 }
197 inline void do_oop_partial_array(oop* p);
199 // This method is applied to the fields of the objects that have just been copied.
200 template <class T> inline void do_oop_evac(T* p, HeapRegion* from);
202 template <class T> inline void deal_with_reference(T* ref_to_scan);
204 inline void dispatch_reference(StarTask ref);
206 // Tries to allocate word_sz in the PLAB of the next "generation" after trying to
207 // allocate into dest. State is the original (source) cset state for the object
208 // that is allocated for.
209 // Returns a non-NULL pointer if successful, and updates dest if required.
210 HeapWord* allocate_in_next_plab(InCSetState const state,
211 InCSetState* dest,
212 size_t word_sz,
213 AllocationContext_t const context);
215 inline InCSetState next_state(InCSetState const state, markOop const m, uint& age);
216 public:
218 oop copy_to_survivor_space(InCSetState const state, oop const obj, markOop const old_mark);
220 void trim_queue();
222 inline void steal_and_trim_queue(RefToScanQueueSet *task_queues);
223 };
225 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP