1 /*
2 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include "config.h"
27 #include "JSContextRef.h"
28 #include "JSContextRefPrivate.h"
29
30 #include "APICast.h"
31 #include "InitializeThreading.h"
32 #include "JSCallbackObject.h"
33 #include "JSClassRef.h"
34 #include "JSGlobalObject.h"
35 #include "JSObject.h"
36 #include <wtf/text/StringHash.h>
37
38 #if OS(DARWIN)
39 #include <mach-o/dyld.h>
40
41 static const int32_t webkitFirstVersionWithConcurrentGlobalContexts = 0x2100500; // 528.5.0
42 #endif
43
44 using namespace JSC;
45
JSContextGroupCreate()46 JSContextGroupRef JSContextGroupCreate()
47 {
48 initializeThreading();
49 return toRef(JSGlobalData::createContextGroup(ThreadStackTypeSmall).leakRef());
50 }
51
JSContextGroupRetain(JSContextGroupRef group)52 JSContextGroupRef JSContextGroupRetain(JSContextGroupRef group)
53 {
54 toJS(group)->ref();
55 return group;
56 }
57
JSContextGroupRelease(JSContextGroupRef group)58 void JSContextGroupRelease(JSContextGroupRef group)
59 {
60 toJS(group)->deref();
61 }
62
JSGlobalContextCreate(JSClassRef globalObjectClass)63 JSGlobalContextRef JSGlobalContextCreate(JSClassRef globalObjectClass)
64 {
65 initializeThreading();
66 #if OS(DARWIN)
67 // When running on Tiger or Leopard, or if the application was linked before JSGlobalContextCreate was changed
68 // to use a unique JSGlobalData, we use a shared one for compatibility.
69 #if !defined(BUILDING_ON_TIGER) && !defined(BUILDING_ON_LEOPARD)
70 if (NSVersionOfLinkTimeLibrary("JavaScriptCore") <= webkitFirstVersionWithConcurrentGlobalContexts) {
71 #else
72 {
73 #endif
74 JSLock lock(LockForReal);
75 return JSGlobalContextCreateInGroup(toRef(&JSGlobalData::sharedInstance()), globalObjectClass);
76 }
77 #endif // OS(DARWIN)
78
79 return JSGlobalContextCreateInGroup(0, globalObjectClass);
80 }
81
82 JSGlobalContextRef JSGlobalContextCreateInGroup(JSContextGroupRef group, JSClassRef globalObjectClass)
83 {
84 initializeThreading();
85
86 JSLock lock(LockForReal);
87 RefPtr<JSGlobalData> globalData = group ? PassRefPtr<JSGlobalData>(toJS(group)) : JSGlobalData::createContextGroup(ThreadStackTypeSmall);
88
89 APIEntryShim entryShim(globalData.get(), false);
90
91 #if ENABLE(JSC_MULTIPLE_THREADS)
92 globalData->makeUsableFromMultipleThreads();
93 #endif
94
95 if (!globalObjectClass) {
96 JSGlobalObject* globalObject = new (globalData.get()) JSGlobalObject(*globalData);
97 return JSGlobalContextRetain(toGlobalRef(globalObject->globalExec()));
98 }
99
100 JSGlobalObject* globalObject = new (globalData.get()) JSCallbackObject<JSGlobalObject>(*globalData, globalObjectClass, JSCallbackObject<JSGlobalObject>::createStructure(*globalData, jsNull()));
101 ExecState* exec = globalObject->globalExec();
102 JSValue prototype = globalObjectClass->prototype(exec);
103 if (!prototype)
104 prototype = jsNull();
105 globalObject->resetPrototype(*globalData, prototype);
106 return JSGlobalContextRetain(toGlobalRef(exec));
107 }
108
109 JSGlobalContextRef JSGlobalContextRetain(JSGlobalContextRef ctx)
110 {
111 ExecState* exec = toJS(ctx);
112 APIEntryShim entryShim(exec);
113
114 JSGlobalData& globalData = exec->globalData();
115 gcProtect(exec->dynamicGlobalObject());
116 globalData.ref();
117 return ctx;
118 }
119
120 void JSGlobalContextRelease(JSGlobalContextRef ctx)
121 {
122 ExecState* exec = toJS(ctx);
123 JSLock lock(exec);
124
125 JSGlobalData& globalData = exec->globalData();
126 JSGlobalObject* dgo = exec->dynamicGlobalObject();
127 IdentifierTable* savedIdentifierTable = wtfThreadData().setCurrentIdentifierTable(globalData.identifierTable);
128
129 // One reference is held by JSGlobalObject, another added by JSGlobalContextRetain().
130 bool releasingContextGroup = globalData.refCount() == 2;
131 bool releasingGlobalObject = Heap::heap(dgo)->unprotect(dgo);
132 // If this is the last reference to a global data, it should also
133 // be the only remaining reference to the global object too!
134 ASSERT(!releasingContextGroup || releasingGlobalObject);
135
136 // An API 'JSGlobalContextRef' retains two things - a global object and a
137 // global data (or context group, in API terminology).
138 // * If this is the last reference to any contexts in the given context group,
139 // call destroy on the heap (the global data is being freed).
140 // * If this was the last reference to the global object, then unprotecting
141 // it may release a lot of GC memory - run the garbage collector now.
142 // * If there are more references remaining the the global object, then do nothing
143 // (specifically that is more protects, which we assume come from other JSGlobalContextRefs).
144 if (releasingContextGroup) {
145 globalData.clearBuiltinStructures();
146 globalData.heap.destroy();
147 } else if (releasingGlobalObject)
148 globalData.heap.collectAllGarbage();
149
150 globalData.deref();
151
152 wtfThreadData().setCurrentIdentifierTable(savedIdentifierTable);
153 }
154
155 JSObjectRef JSContextGetGlobalObject(JSContextRef ctx)
156 {
157 ExecState* exec = toJS(ctx);
158 APIEntryShim entryShim(exec);
159
160 // It is necessary to call toThisObject to get the wrapper object when used with WebCore.
161 return toRef(exec->lexicalGlobalObject()->toThisObject(exec));
162 }
163
164 JSContextGroupRef JSContextGetGroup(JSContextRef ctx)
165 {
166 ExecState* exec = toJS(ctx);
167 return toRef(&exec->globalData());
168 }
169
170 JSGlobalContextRef JSContextGetGlobalContext(JSContextRef ctx)
171 {
172 ExecState* exec = toJS(ctx);
173 APIEntryShim entryShim(exec);
174
175 return toGlobalRef(exec->lexicalGlobalObject()->globalExec());
176 }
177