1/*
2 * Copyright (C) 2008, 2009, 2011 Google 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 are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef ScriptState_h
32#define ScriptState_h
33
34#include "DOMWrapperWorld.h"
35#include <v8.h>
36#include <wtf/Noncopyable.h>
37#include <wtf/RefCounted.h>
38
39namespace WebCore {
40class DOMWrapperWorld;
41class Frame;
42class Node;
43class Page;
44class WorkerContext;
45
46class ScriptState {
47    WTF_MAKE_NONCOPYABLE(ScriptState);
48public:
49    bool hadException() { return !m_exception.IsEmpty(); }
50    void setException(v8::Local<v8::Value> exception)
51    {
52        m_exception = exception;
53    }
54    v8::Local<v8::Value> exception() { return m_exception; }
55
56    v8::Local<v8::Context> context() const
57    {
58        return v8::Local<v8::Context>::New(m_context);
59    }
60
61    static ScriptState* forContext(v8::Local<v8::Context>);
62    static ScriptState* current();
63
64protected:
65    ScriptState() { }
66    ~ScriptState();
67
68private:
69    friend ScriptState* mainWorldScriptState(Frame*);
70    explicit ScriptState(v8::Handle<v8::Context>);
71
72    static void weakReferenceCallback(v8::Persistent<v8::Value> object, void* parameter);
73
74    v8::Local<v8::Value> m_exception;
75    v8::Persistent<v8::Context> m_context;
76};
77
78class EmptyScriptState : public ScriptState {
79public:
80    EmptyScriptState() : ScriptState() { }
81    ~EmptyScriptState() { }
82};
83
84class ScriptStateProtectedPtr {
85    WTF_MAKE_NONCOPYABLE(ScriptStateProtectedPtr);
86public:
87    ScriptStateProtectedPtr() : m_scriptState(0) { }
88    ScriptStateProtectedPtr(ScriptState* scriptState) : m_scriptState(scriptState)
89    {
90        v8::HandleScope handleScope;
91        // Keep the context from being GC'ed. ScriptState is guaranteed to be live while the context is live.
92        m_context = v8::Persistent<v8::Context>::New(scriptState->context());
93    }
94    ~ScriptStateProtectedPtr()
95    {
96        if (!m_context.IsEmpty()) {
97            m_context.Dispose();
98            m_context.Clear();
99        }
100    }
101    ScriptState* get() const { return m_scriptState; }
102private:
103    ScriptState* m_scriptState;
104    v8::Persistent<v8::Context> m_context;
105};
106
107ScriptState* mainWorldScriptState(Frame*);
108
109ScriptState* scriptStateFromNode(DOMWrapperWorld*, Node*);
110ScriptState* scriptStateFromPage(DOMWrapperWorld*, Page*);
111
112#if ENABLE(WORKERS)
113ScriptState* scriptStateFromWorkerContext(WorkerContext*);
114#endif
115
116inline DOMWrapperWorld* debuggerWorld() { return mainThreadNormalWorld(); }
117inline DOMWrapperWorld* pluginWorld() { return mainThreadNormalWorld(); }
118
119}
120
121#endif // ScriptState_h
122