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 JSContextGroupRef javaScriptThreadsGroup;
41
42 static pthread_mutex_t javaScriptThreadsMutex = PTHREAD_MUTEX_INITIALIZER;
43 static bool javaScriptThreadsShouldTerminate;
44
45 static const int javaScriptThreadsCount = 4;
46
47 typedef HashSet<pthread_t> ThreadSet;
48
javaScriptThreads()49 static ThreadSet* javaScriptThreads()
50 {
51 ASSERT(pthread_mutex_trylock(&javaScriptThreadsMutex) == EBUSY);
52 static ThreadSet staticJavaScriptThreads;
53 return &staticJavaScriptThreads;
54 }
55
56 // This function exercises JSC in a loop until javaScriptThreadsShouldTerminate
57 // becomes true or it probabilistically decides to spawn a replacement thread and exit.
runJavaScriptThread(void * arg)58 void* runJavaScriptThread(void* arg)
59 {
60 static const char* const script =
61 "var array = [];"
62 "for (var i = 0; i < 1024; i++) {"
63 " array.push(String(i));"
64 "}";
65
66 pthread_mutex_lock(&javaScriptThreadsMutex);
67 JSGlobalContextRef ctx = JSGlobalContextCreateInGroup(javaScriptThreadsGroup, 0);
68 pthread_mutex_unlock(&javaScriptThreadsMutex);
69
70 pthread_mutex_lock(&javaScriptThreadsMutex);
71 JSStringRef scriptRef = JSStringCreateWithUTF8CString(script);
72 pthread_mutex_unlock(&javaScriptThreadsMutex);
73
74 while (1) {
75 pthread_mutex_lock(&javaScriptThreadsMutex);
76 JSValueRef exception = 0;
77 JSEvaluateScript(ctx, scriptRef, 0, 0, 1, &exception);
78 ASSERT(!exception);
79 pthread_mutex_unlock(&javaScriptThreadsMutex);
80
81 pthread_mutex_lock(&javaScriptThreadsMutex);
82 size_t valuesCount = 1024;
83 JSValueRef values[valuesCount];
84 for (size_t i = 0; i < valuesCount; ++i)
85 values[i] = JSObjectMake(ctx, 0, 0);
86 pthread_mutex_unlock(&javaScriptThreadsMutex);
87
88 // Check for cancellation.
89 if (javaScriptThreadsShouldTerminate)
90 goto done;
91
92 // Respawn probabilistically.
93 if (random() % 5 == 0) {
94 pthread_mutex_lock(&javaScriptThreadsMutex);
95 pthread_t pthread;
96 pthread_create(&pthread, 0, &runJavaScriptThread, 0);
97 pthread_detach(pthread);
98 javaScriptThreads()->add(pthread);
99 pthread_mutex_unlock(&javaScriptThreadsMutex);
100 goto done;
101 }
102 }
103
104 done:
105 pthread_mutex_lock(&javaScriptThreadsMutex);
106 JSStringRelease(scriptRef);
107 JSGarbageCollect(ctx);
108 JSGlobalContextRelease(ctx);
109 javaScriptThreads()->remove(pthread_self());
110 pthread_mutex_unlock(&javaScriptThreadsMutex);
111 return 0;
112 }
113
startJavaScriptThreads()114 void startJavaScriptThreads()
115 {
116 javaScriptThreadsGroup = JSContextGroupCreate();
117
118 pthread_mutex_lock(&javaScriptThreadsMutex);
119
120 for (int i = 0; i < javaScriptThreadsCount; i++) {
121 pthread_t pthread;
122 pthread_create(&pthread, 0, &runJavaScriptThread, 0);
123 pthread_detach(pthread);
124 javaScriptThreads()->add(pthread);
125 }
126
127 pthread_mutex_unlock(&javaScriptThreadsMutex);
128 }
129
stopJavaScriptThreads()130 void stopJavaScriptThreads()
131 {
132 pthread_mutex_lock(&javaScriptThreadsMutex);
133
134 javaScriptThreadsShouldTerminate = true;
135
136 pthread_mutex_unlock(&javaScriptThreadsMutex);
137
138 while (true) {
139 pthread_mutex_lock(&javaScriptThreadsMutex);
140 int threadCount = javaScriptThreads()->size();
141 pthread_mutex_unlock(&javaScriptThreadsMutex);
142
143 if (!threadCount)
144 break;
145
146 usleep(1000);
147 }
148 }
149