Mercurial > hg > graal-jvmci-8
comparison src/share/vm/utilities/taskqueue.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | 37f87013dfd8 |
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-1:000000000000 | 0:a61af66fc99e |
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1 /* | |
2 * Copyright 2001-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 # include "incls/_precompiled.incl" | |
26 # include "incls/_taskqueue.cpp.incl" | |
27 | |
28 bool TaskQueueSuper::peek() { | |
29 return _bottom != _age.top(); | |
30 } | |
31 | |
32 int TaskQueueSetSuper::randomParkAndMiller(int *seed0) { | |
33 const int a = 16807; | |
34 const int m = 2147483647; | |
35 const int q = 127773; /* m div a */ | |
36 const int r = 2836; /* m mod a */ | |
37 assert(sizeof(int) == 4, "I think this relies on that"); | |
38 int seed = *seed0; | |
39 int hi = seed / q; | |
40 int lo = seed % q; | |
41 int test = a * lo - r * hi; | |
42 if (test > 0) | |
43 seed = test; | |
44 else | |
45 seed = test + m; | |
46 *seed0 = seed; | |
47 return seed; | |
48 } | |
49 | |
50 ParallelTaskTerminator:: | |
51 ParallelTaskTerminator(int n_threads, TaskQueueSetSuper* queue_set) : | |
52 _n_threads(n_threads), | |
53 _queue_set(queue_set), | |
54 _offered_termination(0) {} | |
55 | |
56 bool ParallelTaskTerminator::peek_in_queue_set() { | |
57 return _queue_set->peek(); | |
58 } | |
59 | |
60 void ParallelTaskTerminator::yield() { | |
61 os::yield(); | |
62 } | |
63 | |
64 void ParallelTaskTerminator::sleep(uint millis) { | |
65 os::sleep(Thread::current(), millis, false); | |
66 } | |
67 | |
68 bool ParallelTaskTerminator::offer_termination() { | |
69 Atomic::inc(&_offered_termination); | |
70 | |
71 juint yield_count = 0; | |
72 while (true) { | |
73 if (_offered_termination == _n_threads) { | |
74 //inner_termination_loop(); | |
75 return true; | |
76 } else { | |
77 if (yield_count <= WorkStealingYieldsBeforeSleep) { | |
78 yield_count++; | |
79 yield(); | |
80 } else { | |
81 if (PrintGCDetails && Verbose) { | |
82 gclog_or_tty->print_cr("ParallelTaskTerminator::offer_termination() " | |
83 "thread %d sleeps after %d yields", | |
84 Thread::current(), yield_count); | |
85 } | |
86 yield_count = 0; | |
87 // A sleep will cause this processor to seek work on another processor's | |
88 // runqueue, if it has nothing else to run (as opposed to the yield | |
89 // which may only move the thread to the end of the this processor's | |
90 // runqueue). | |
91 sleep(WorkStealingSleepMillis); | |
92 } | |
93 | |
94 if (peek_in_queue_set()) { | |
95 Atomic::dec(&_offered_termination); | |
96 return false; | |
97 } | |
98 } | |
99 } | |
100 } | |
101 | |
102 void ParallelTaskTerminator::reset_for_reuse() { | |
103 if (_offered_termination != 0) { | |
104 assert(_offered_termination == _n_threads, | |
105 "Terminator may still be in use"); | |
106 _offered_termination = 0; | |
107 } | |
108 } | |
109 | |
110 bool ChunkTaskQueueWithOverflow::is_empty() { | |
111 return (_chunk_queue.size() == 0) && | |
112 (_overflow_stack->length() == 0); | |
113 } | |
114 | |
115 bool ChunkTaskQueueWithOverflow::stealable_is_empty() { | |
116 return _chunk_queue.size() == 0; | |
117 } | |
118 | |
119 bool ChunkTaskQueueWithOverflow::overflow_is_empty() { | |
120 return _overflow_stack->length() == 0; | |
121 } | |
122 | |
123 void ChunkTaskQueueWithOverflow::initialize() { | |
124 _chunk_queue.initialize(); | |
125 assert(_overflow_stack == 0, "Creating memory leak"); | |
126 _overflow_stack = | |
127 new (ResourceObj::C_HEAP) GrowableArray<ChunkTask>(10, true); | |
128 } | |
129 | |
130 void ChunkTaskQueueWithOverflow::save(ChunkTask t) { | |
131 if (TraceChunkTasksQueuing && Verbose) { | |
132 gclog_or_tty->print_cr("CTQ: save " PTR_FORMAT, t); | |
133 } | |
134 if(!_chunk_queue.push(t)) { | |
135 _overflow_stack->push(t); | |
136 } | |
137 } | |
138 | |
139 // Note that using this method will retrieve all chunks | |
140 // that have been saved but that it will always check | |
141 // the overflow stack. It may be more efficient to | |
142 // check the stealable queue and the overflow stack | |
143 // separately. | |
144 bool ChunkTaskQueueWithOverflow::retrieve(ChunkTask& chunk_task) { | |
145 bool result = retrieve_from_overflow(chunk_task); | |
146 if (!result) { | |
147 result = retrieve_from_stealable_queue(chunk_task); | |
148 } | |
149 if (TraceChunkTasksQueuing && Verbose && result) { | |
150 gclog_or_tty->print_cr(" CTQ: retrieve " PTR_FORMAT, result); | |
151 } | |
152 return result; | |
153 } | |
154 | |
155 bool ChunkTaskQueueWithOverflow::retrieve_from_stealable_queue( | |
156 ChunkTask& chunk_task) { | |
157 bool result = _chunk_queue.pop_local(chunk_task); | |
158 if (TraceChunkTasksQueuing && Verbose) { | |
159 gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, chunk_task); | |
160 } | |
161 return result; | |
162 } | |
163 | |
164 bool ChunkTaskQueueWithOverflow::retrieve_from_overflow( | |
165 ChunkTask& chunk_task) { | |
166 bool result; | |
167 if (!_overflow_stack->is_empty()) { | |
168 chunk_task = _overflow_stack->pop(); | |
169 result = true; | |
170 } else { | |
171 chunk_task = (ChunkTask) NULL; | |
172 result = false; | |
173 } | |
174 if (TraceChunkTasksQueuing && Verbose) { | |
175 gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, chunk_task); | |
176 } | |
177 return result; | |
178 } |