Sat, 18 May 2013 20:41:01 -0700
8014262: PrintStringTableStatistics should include more footprint info
Summary: Added info for the string/symbol objects and the hash entries
Reviewed-by: coleenp, rbackman
1 /*
2 * Copyright (c) 2001, 2013, 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.
22 *
23 */
25 #include "precompiled.hpp"
26 #include "oops/oop.inline.hpp"
27 #include "runtime/os.hpp"
28 #include "runtime/thread.inline.hpp"
29 #include "utilities/debug.hpp"
30 #include "utilities/stack.inline.hpp"
31 #include "utilities/taskqueue.hpp"
33 #ifdef TRACESPINNING
34 uint ParallelTaskTerminator::_total_yields = 0;
35 uint ParallelTaskTerminator::_total_spins = 0;
36 uint ParallelTaskTerminator::_total_peeks = 0;
37 #endif
39 #if TASKQUEUE_STATS
40 const char * const TaskQueueStats::_names[last_stat_id] = {
41 "qpush", "qpop", "qpop-s", "qattempt", "qsteal", "opush", "omax"
42 };
44 TaskQueueStats & TaskQueueStats::operator +=(const TaskQueueStats & addend)
45 {
46 for (unsigned int i = 0; i < last_stat_id; ++i) {
47 _stats[i] += addend._stats[i];
48 }
49 return *this;
50 }
52 void TaskQueueStats::print_header(unsigned int line, outputStream* const stream,
53 unsigned int width)
54 {
55 // Use a width w: 1 <= w <= max_width
56 const unsigned int max_width = 40;
57 const unsigned int w = MAX2(MIN2(width, max_width), 1U);
59 if (line == 0) { // spaces equal in width to the header
60 const unsigned int hdr_width = w * last_stat_id + last_stat_id - 1;
61 stream->print("%*s", hdr_width, " ");
62 } else if (line == 1) { // labels
63 stream->print("%*s", w, _names[0]);
64 for (unsigned int i = 1; i < last_stat_id; ++i) {
65 stream->print(" %*s", w, _names[i]);
66 }
67 } else if (line == 2) { // dashed lines
68 char dashes[max_width + 1];
69 memset(dashes, '-', w);
70 dashes[w] = '\0';
71 stream->print("%s", dashes);
72 for (unsigned int i = 1; i < last_stat_id; ++i) {
73 stream->print(" %s", dashes);
74 }
75 }
76 }
78 void TaskQueueStats::print(outputStream* stream, unsigned int width) const
79 {
80 #define FMT SIZE_FORMAT_W(*)
81 stream->print(FMT, width, _stats[0]);
82 for (unsigned int i = 1; i < last_stat_id; ++i) {
83 stream->print(" " FMT, width, _stats[i]);
84 }
85 #undef FMT
86 }
88 #ifdef ASSERT
89 // Invariants which should hold after a TaskQueue has been emptied and is
90 // quiescent; they do not hold at arbitrary times.
91 void TaskQueueStats::verify() const
92 {
93 assert(get(push) == get(pop) + get(steal),
94 err_msg("push=" SIZE_FORMAT " pop=" SIZE_FORMAT " steal=" SIZE_FORMAT,
95 get(push), get(pop), get(steal)));
96 assert(get(pop_slow) <= get(pop),
97 err_msg("pop_slow=" SIZE_FORMAT " pop=" SIZE_FORMAT,
98 get(pop_slow), get(pop)));
99 assert(get(steal) <= get(steal_attempt),
100 err_msg("steal=" SIZE_FORMAT " steal_attempt=" SIZE_FORMAT,
101 get(steal), get(steal_attempt)));
102 assert(get(overflow) == 0 || get(push) != 0,
103 err_msg("overflow=" SIZE_FORMAT " push=" SIZE_FORMAT,
104 get(overflow), get(push)));
105 assert(get(overflow_max_len) == 0 || get(overflow) != 0,
106 err_msg("overflow_max_len=" SIZE_FORMAT " overflow=" SIZE_FORMAT,
107 get(overflow_max_len), get(overflow)));
108 }
109 #endif // ASSERT
110 #endif // TASKQUEUE_STATS
112 int TaskQueueSetSuper::randomParkAndMiller(int *seed0) {
113 const int a = 16807;
114 const int m = 2147483647;
115 const int q = 127773; /* m div a */
116 const int r = 2836; /* m mod a */
117 assert(sizeof(int) == 4, "I think this relies on that");
118 int seed = *seed0;
119 int hi = seed / q;
120 int lo = seed % q;
121 int test = a * lo - r * hi;
122 if (test > 0)
123 seed = test;
124 else
125 seed = test + m;
126 *seed0 = seed;
127 return seed;
128 }
130 ParallelTaskTerminator::
131 ParallelTaskTerminator(int n_threads, TaskQueueSetSuper* queue_set) :
132 _n_threads(n_threads),
133 _queue_set(queue_set),
134 _offered_termination(0) {}
136 bool ParallelTaskTerminator::peek_in_queue_set() {
137 return _queue_set->peek();
138 }
140 void ParallelTaskTerminator::yield() {
141 assert(_offered_termination <= _n_threads, "Invariant");
142 os::yield();
143 }
145 void ParallelTaskTerminator::sleep(uint millis) {
146 assert(_offered_termination <= _n_threads, "Invariant");
147 os::sleep(Thread::current(), millis, false);
148 }
150 bool
151 ParallelTaskTerminator::offer_termination(TerminatorTerminator* terminator) {
152 assert(_n_threads > 0, "Initialization is incorrect");
153 assert(_offered_termination < _n_threads, "Invariant");
154 Atomic::inc(&_offered_termination);
156 uint yield_count = 0;
157 // Number of hard spin loops done since last yield
158 uint hard_spin_count = 0;
159 // Number of iterations in the hard spin loop.
160 uint hard_spin_limit = WorkStealingHardSpins;
162 // If WorkStealingSpinToYieldRatio is 0, no hard spinning is done.
163 // If it is greater than 0, then start with a small number
164 // of spins and increase number with each turn at spinning until
165 // the count of hard spins exceeds WorkStealingSpinToYieldRatio.
166 // Then do a yield() call and start spinning afresh.
167 if (WorkStealingSpinToYieldRatio > 0) {
168 hard_spin_limit = WorkStealingHardSpins >> WorkStealingSpinToYieldRatio;
169 hard_spin_limit = MAX2(hard_spin_limit, 1U);
170 }
171 // Remember the initial spin limit.
172 uint hard_spin_start = hard_spin_limit;
174 // Loop waiting for all threads to offer termination or
175 // more work.
176 while (true) {
177 assert(_offered_termination <= _n_threads, "Invariant");
178 // Are all threads offering termination?
179 if (_offered_termination == _n_threads) {
180 return true;
181 } else {
182 // Look for more work.
183 // Periodically sleep() instead of yield() to give threads
184 // waiting on the cores the chance to grab this code
185 if (yield_count <= WorkStealingYieldsBeforeSleep) {
186 // Do a yield or hardspin. For purposes of deciding whether
187 // to sleep, count this as a yield.
188 yield_count++;
190 // Periodically call yield() instead spinning
191 // After WorkStealingSpinToYieldRatio spins, do a yield() call
192 // and reset the counts and starting limit.
193 if (hard_spin_count > WorkStealingSpinToYieldRatio) {
194 yield();
195 hard_spin_count = 0;
196 hard_spin_limit = hard_spin_start;
197 #ifdef TRACESPINNING
198 _total_yields++;
199 #endif
200 } else {
201 // Hard spin this time
202 // Increase the hard spinning period but only up to a limit.
203 hard_spin_limit = MIN2(2*hard_spin_limit,
204 (uint) WorkStealingHardSpins);
205 for (uint j = 0; j < hard_spin_limit; j++) {
206 SpinPause();
207 }
208 hard_spin_count++;
209 #ifdef TRACESPINNING
210 _total_spins++;
211 #endif
212 }
213 } else {
214 if (PrintGCDetails && Verbose) {
215 gclog_or_tty->print_cr("ParallelTaskTerminator::offer_termination() "
216 "thread %d sleeps after %d yields",
217 Thread::current(), yield_count);
218 }
219 yield_count = 0;
220 // A sleep will cause this processor to seek work on another processor's
221 // runqueue, if it has nothing else to run (as opposed to the yield
222 // which may only move the thread to the end of the this processor's
223 // runqueue).
224 sleep(WorkStealingSleepMillis);
225 }
227 #ifdef TRACESPINNING
228 _total_peeks++;
229 #endif
230 if (peek_in_queue_set() ||
231 (terminator != NULL && terminator->should_exit_termination())) {
232 Atomic::dec(&_offered_termination);
233 assert(_offered_termination < _n_threads, "Invariant");
234 return false;
235 }
236 }
237 }
238 }
240 #ifdef TRACESPINNING
241 void ParallelTaskTerminator::print_termination_counts() {
242 gclog_or_tty->print_cr("ParallelTaskTerminator Total yields: " UINT32_FORMAT
243 " Total spins: " UINT32_FORMAT " Total peeks: " UINT32_FORMAT,
244 total_yields(),
245 total_spins(),
246 total_peeks());
247 }
248 #endif
250 void ParallelTaskTerminator::reset_for_reuse() {
251 if (_offered_termination != 0) {
252 assert(_offered_termination == _n_threads,
253 "Terminator may still be in use");
254 _offered_termination = 0;
255 }
256 }
258 #ifdef ASSERT
259 bool ObjArrayTask::is_valid() const {
260 return _obj != NULL && _obj->is_objArray() && _index > 0 &&
261 _index < objArrayOop(_obj)->length();
262 }
263 #endif // ASSERT
265 void ParallelTaskTerminator::reset_for_reuse(int n_threads) {
266 reset_for_reuse();
267 _n_threads = n_threads;
268 }