API/JSContextRef.cpp

   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
  29 #include "APICast.h"
  30 #include "InitializeThreading.h"
  31 #include "JSCallbackObject.h"
  32 #include "JSClassRef.h"
  33 #include "JSGlobalObject.h"
  34 #include "JSObject.h"
  35 #include <wtf/Platform.h>
  36
  37 #if PLATFORM(DARWIN)
  38 #include <mach-o/dyld.h>
  39
  40 static const int32_t webkitFirstVersionWithConcurrentGlobalContexts = 0x2100500; // 528.5.0
  41 #endif
  42
  43 using namespace JSC;
  44
  45 JSContextGroupRef JSContextGroupCreate()
  46 {
  47     initializeThreading();
  48     return toRef(JSGlobalData::create().releaseRef());
  49 }
  50
  51 JSContextGroupRef JSContextGroupRetain(JSContextGroupRef group)
  52 {
  53     toJS(group)->ref();
  54     return group;
  55 }
  56
  57 void JSContextGroupRelease(JSContextGroupRef group)
  58 {
  59     toJS(group)->deref();
  60 }
  61
  62 JSGlobalContextRef JSGlobalContextCreate(JSClassRef globalObjectClass)
  63 {
  64     initializeThreading();
  65 #if PLATFORM(DARWIN)
  66     // When running on Tiger or Leopard, or if the application was linked before JSGlobalContextCreate was changed
  67     // to use a unique JSGlobalData, we use a shared one for compatibility.
  68 #if !defined(BUILDING_ON_TIGER) && !defined(BUILDING_ON_LEOPARD)
  69     if (NSVersionOfLinkTimeLibrary("JavaScriptCore") <= webkitFirstVersionWithConcurrentGlobalContexts) {
  70 #else
  71     {
  72 #endif
  73         JSLock lock(true);
  74         return JSGlobalContextCreateInGroup(toRef(&JSGlobalData::sharedInstance()), globalObjectClass);
  75     }
  76 #endif // PLATFORM(DARWIN)
  77
  78     return JSGlobalContextCreateInGroup(0, globalObjectClass);
  79 }
  80
  81 JSGlobalContextRef JSGlobalContextCreateInGroup(JSContextGroupRef group, JSClassRef globalObjectClass)
  82 {
  83     initializeThreading();
  84
  85     JSLock lock(true);
  86
  87     RefPtr<JSGlobalData> globalData = group ? PassRefPtr<JSGlobalData>(toJS(group)) : JSGlobalData::create();
  88
  89 #if ENABLE(JSC_MULTIPLE_THREADS)
  90     globalData->makeUsableFromMultipleThreads();
  91 #endif
  92
  93     if (!globalObjectClass) {
  94         JSGlobalObject* globalObject = new (globalData.get()) JSGlobalObject;
  95         return JSGlobalContextRetain(toGlobalRef(globalObject->globalExec()));
  96     }
  97
  98     JSGlobalObject* globalObject = new (globalData.get()) JSCallbackObject<JSGlobalObject>(globalObjectClass);
  99     ExecState* exec = globalObject->globalExec();
 100     JSValuePtr prototype = globalObjectClass->prototype(exec);
 101     if (!prototype)
 102         prototype = jsNull();
 103     globalObject->resetPrototype(prototype);
 104     return JSGlobalContextRetain(toGlobalRef(exec));
 105 }
 106
 107 JSGlobalContextRef JSGlobalContextRetain(JSGlobalContextRef ctx)
 108 {
 109     ExecState* exec = toJS(ctx);
 110     JSLock lock(exec);
 111
 112     JSGlobalData& globalData = exec->globalData();
 113
 114     globalData.heap.registerThread();
 115
 116     gcProtect(exec->dynamicGlobalObject());
 117     globalData.ref();
 118     return ctx;
 119 }
 120
 121 void JSGlobalContextRelease(JSGlobalContextRef ctx)
 122 {
 123     ExecState* exec = toJS(ctx);
 124     JSLock lock(exec);
 125
 126     gcUnprotect(exec->dynamicGlobalObject());
 127
 128     JSGlobalData& globalData = exec->globalData();
 129     if (globalData.refCount() == 2) { // One reference is held by JSGlobalObject, another added by JSGlobalContextRetain().
 130         // The last reference was released, this is our last chance to collect.
 131         ASSERT(!globalData.heap.protectedObjectCount());
 132         ASSERT(!globalData.heap.isBusy());
 133         globalData.heap.destroy();
 134     } else
 135         globalData.heap.collect();
 136
 137     globalData.deref();
 138 }
 139
 140 JSObjectRef JSContextGetGlobalObject(JSContextRef ctx)
 141 {
 142     ExecState* exec = toJS(ctx);
 143     exec->globalData().heap.registerThread();
 144     JSLock lock(exec);
 145
 146     // It is necessary to call toThisObject to get the wrapper object when used with WebCore.
 147     return toRef(exec->lexicalGlobalObject()->toThisObject(exec));
 148 }
 149
 150 JSContextGroupRef JSContextGetGroup(JSContextRef ctx)
 151 {
 152     ExecState* exec = toJS(ctx);
 153     return toRef(&exec->globalData());
 154 }