1 /*
2 * Copyright (C) 2005, 2006, 2007 Apple Inc. All rights reserved.
3 * (C) 2007 Graham Dennis (graham.dennis@gmail.com)
4 * (C) 2007 Eric Seidel <eric@webkit.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
16 * its contributors may be used to endorse or promote products derived
17 * from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
20 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
23 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
26 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include "config.h"
32 #include "JavaScriptThreading.h"
33
34 #include <CoreFoundation/CoreFoundation.h>
35 #include <JavaScriptCore/JavaScriptCore.h>
36 #include <pthread.h>
37 #include <wtf/Assertions.h>
38 #include <wtf/HashSet.h>
39
40 static pthread_mutex_t javaScriptThreadsMutex = PTHREAD_MUTEX_INITIALIZER;
41 static bool javaScriptThreadsShouldTerminate;
42
43 static const int javaScriptThreadsCount = 4;
44
45 typedef HashSet<pthread_t> ThreadSet;
46
javaScriptThreads()47 static ThreadSet* javaScriptThreads()
48 {
49 ASSERT(pthread_mutex_trylock(&javaScriptThreadsMutex) == EBUSY);
50 static ThreadSet staticJavaScriptThreads;
51 return &staticJavaScriptThreads;
52 }
53
54 // Loops forever, running a script and randomly respawning, until
55 // javaScriptThreadsShouldTerminate becomes true.
runJavaScriptThread(void * arg)56 void* runJavaScriptThread(void* arg)
57 {
58 const char* const script =
59 "var array = [];"
60 "for (var i = 0; i < 10; i++) {"
61 " array.push(String(i));"
62 "}";
63
64 while (1) {
65 JSGlobalContextRef ctx = JSGlobalContextCreate(0);
66 JSStringRef scriptRef = JSStringCreateWithUTF8CString(script);
67
68 JSValueRef exception = 0;
69 JSEvaluateScript(ctx, scriptRef, 0, 0, 1, &exception);
70 ASSERT(!exception);
71
72 JSGarbageCollect(ctx);
73 JSGlobalContextRelease(ctx);
74 JSStringRelease(scriptRef);
75
76 JSGarbageCollect(0);
77
78 pthread_mutex_lock(&javaScriptThreadsMutex);
79
80 // Check for cancellation.
81 if (javaScriptThreadsShouldTerminate) {
82 javaScriptThreads()->remove(pthread_self());
83 pthread_mutex_unlock(&javaScriptThreadsMutex);
84 return 0;
85 }
86
87 // Respawn probabilistically.
88 if (random() % 5 == 0) {
89 pthread_t pthread;
90 pthread_create(&pthread, 0, &runJavaScriptThread, 0);
91 pthread_detach(pthread);
92
93 javaScriptThreads()->remove(pthread_self());
94 javaScriptThreads()->add(pthread);
95
96 pthread_mutex_unlock(&javaScriptThreadsMutex);
97 return 0;
98 }
99
100 pthread_mutex_unlock(&javaScriptThreadsMutex);
101 }
102 }
103
startJavaScriptThreads()104 void startJavaScriptThreads()
105 {
106 pthread_mutex_lock(&javaScriptThreadsMutex);
107
108 for (int i = 0; i < javaScriptThreadsCount; i++) {
109 pthread_t pthread;
110 pthread_create(&pthread, 0, &runJavaScriptThread, 0);
111 pthread_detach(pthread);
112 javaScriptThreads()->add(pthread);
113 }
114
115 pthread_mutex_unlock(&javaScriptThreadsMutex);
116 }
117
stopJavaScriptThreads()118 void stopJavaScriptThreads()
119 {
120 pthread_mutex_lock(&javaScriptThreadsMutex);
121
122 javaScriptThreadsShouldTerminate = true;
123
124 ASSERT(javaScriptThreads()->size() == javaScriptThreadsCount);
125
126 pthread_mutex_unlock(&javaScriptThreadsMutex);
127
128 while (true) {
129 pthread_mutex_lock(&javaScriptThreadsMutex);
130 int threadCount = javaScriptThreads()->size();
131 pthread_mutex_unlock(&javaScriptThreadsMutex);
132
133 if (!threadCount)
134 break;
135
136 usleep(1000);
137 }
138 }
139