Fri, 07 Nov 2008 09:29:38 -0800
6462850: generate biased locking code in C2 ideal graph
Summary: Inline biased locking code in C2 ideal graph during macro nodes expansion
Reviewed-by: never
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 */
25 # include "incls/_precompiled.incl"
26 # include "incls/_taskqueue.cpp.incl"
28 bool TaskQueueSuper::peek() {
29 return _bottom != _age.top();
30 }
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 }
50 ParallelTaskTerminator::
51 ParallelTaskTerminator(int n_threads, TaskQueueSetSuper* queue_set) :
52 _n_threads(n_threads),
53 _queue_set(queue_set),
54 _offered_termination(0) {}
56 bool ParallelTaskTerminator::peek_in_queue_set() {
57 return _queue_set->peek();
58 }
60 void ParallelTaskTerminator::yield() {
61 os::yield();
62 }
64 void ParallelTaskTerminator::sleep(uint millis) {
65 os::sleep(Thread::current(), millis, false);
66 }
68 bool
69 ParallelTaskTerminator::offer_termination(TerminatorTerminator* terminator) {
70 Atomic::inc(&_offered_termination);
72 juint yield_count = 0;
73 while (true) {
74 if (_offered_termination == _n_threads) {
75 //inner_termination_loop();
76 return true;
77 } else {
78 if (yield_count <= WorkStealingYieldsBeforeSleep) {
79 yield_count++;
80 yield();
81 } else {
82 if (PrintGCDetails && Verbose) {
83 gclog_or_tty->print_cr("ParallelTaskTerminator::offer_termination() "
84 "thread %d sleeps after %d yields",
85 Thread::current(), yield_count);
86 }
87 yield_count = 0;
88 // A sleep will cause this processor to seek work on another processor's
89 // runqueue, if it has nothing else to run (as opposed to the yield
90 // which may only move the thread to the end of the this processor's
91 // runqueue).
92 sleep(WorkStealingSleepMillis);
93 }
95 if (peek_in_queue_set() ||
96 (terminator != NULL && terminator->should_exit_termination())) {
97 Atomic::dec(&_offered_termination);
98 return false;
99 }
100 }
101 }
102 }
104 void ParallelTaskTerminator::reset_for_reuse() {
105 if (_offered_termination != 0) {
106 assert(_offered_termination == _n_threads,
107 "Terminator may still be in use");
108 _offered_termination = 0;
109 }
110 }
112 bool RegionTaskQueueWithOverflow::is_empty() {
113 return (_region_queue.size() == 0) &&
114 (_overflow_stack->length() == 0);
115 }
117 bool RegionTaskQueueWithOverflow::stealable_is_empty() {
118 return _region_queue.size() == 0;
119 }
121 bool RegionTaskQueueWithOverflow::overflow_is_empty() {
122 return _overflow_stack->length() == 0;
123 }
125 void RegionTaskQueueWithOverflow::initialize() {
126 _region_queue.initialize();
127 assert(_overflow_stack == 0, "Creating memory leak");
128 _overflow_stack =
129 new (ResourceObj::C_HEAP) GrowableArray<RegionTask>(10, true);
130 }
132 void RegionTaskQueueWithOverflow::save(RegionTask t) {
133 if (TraceRegionTasksQueuing && Verbose) {
134 gclog_or_tty->print_cr("CTQ: save " PTR_FORMAT, t);
135 }
136 if(!_region_queue.push(t)) {
137 _overflow_stack->push(t);
138 }
139 }
141 // Note that using this method will retrieve all regions
142 // that have been saved but that it will always check
143 // the overflow stack. It may be more efficient to
144 // check the stealable queue and the overflow stack
145 // separately.
146 bool RegionTaskQueueWithOverflow::retrieve(RegionTask& region_task) {
147 bool result = retrieve_from_overflow(region_task);
148 if (!result) {
149 result = retrieve_from_stealable_queue(region_task);
150 }
151 if (TraceRegionTasksQueuing && Verbose && result) {
152 gclog_or_tty->print_cr(" CTQ: retrieve " PTR_FORMAT, result);
153 }
154 return result;
155 }
157 bool RegionTaskQueueWithOverflow::retrieve_from_stealable_queue(
158 RegionTask& region_task) {
159 bool result = _region_queue.pop_local(region_task);
160 if (TraceRegionTasksQueuing && Verbose) {
161 gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, region_task);
162 }
163 return result;
164 }
166 bool
167 RegionTaskQueueWithOverflow::retrieve_from_overflow(RegionTask& region_task) {
168 bool result;
169 if (!_overflow_stack->is_empty()) {
170 region_task = _overflow_stack->pop();
171 result = true;
172 } else {
173 region_task = (RegionTask) NULL;
174 result = false;
175 }
176 if (TraceRegionTasksQueuing && Verbose) {
177 gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, region_task);
178 }
179 return result;
180 }