1/*
2 * Copyright (C) 2010 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#include "config.h"
32#include "ActiveDOMCallback.h"
33
34#include "ActiveDOMObject.h"
35#include "ScriptExecutionContext.h"
36#include <wtf/PassOwnPtr.h>
37#include <wtf/ThreadingPrimitives.h>
38
39namespace WebCore {
40
41static void destroyOnContextThread(PassOwnPtr<ActiveDOMObjectCallbackImpl>);
42
43class DestroyOnContextThreadTask : public ScriptExecutionContext::Task {
44public:
45    static PassOwnPtr<DestroyOnContextThreadTask> create(PassOwnPtr<ActiveDOMObjectCallbackImpl> impl)
46    {
47        return adoptPtr(new DestroyOnContextThreadTask(impl));
48    }
49
50    virtual void performTask(ScriptExecutionContext*)
51    {
52        destroyOnContextThread(m_impl.release());
53    }
54
55private:
56    DestroyOnContextThreadTask(PassOwnPtr<ActiveDOMObjectCallbackImpl> impl)
57        : m_impl(impl)
58    {
59    }
60
61    OwnPtr<ActiveDOMObjectCallbackImpl> m_impl;
62};
63
64class ActiveDOMObjectCallbackImpl : public ActiveDOMObject {
65public:
66    ActiveDOMObjectCallbackImpl(ScriptExecutionContext* context)
67        : ActiveDOMObject(context, this)
68        , m_suspended(false)
69        , m_stopped(false)
70    {
71    }
72
73    virtual void contextDestroyed()
74    {
75        MutexLocker locker(m_mutex);
76        ActiveDOMObject::contextDestroyed();
77    }
78    virtual bool canSuspend() const { return false; }
79    virtual void suspend(ReasonForSuspension)
80    {
81        MutexLocker locker(m_mutex);
82        m_suspended = true;
83    }
84    virtual void resume()
85    {
86        MutexLocker locker(m_mutex);
87        m_suspended = false;
88    }
89    virtual void stop()
90    {
91        MutexLocker locker(m_mutex);
92        m_stopped = true;
93    }
94    bool canInvokeCallback()
95    {
96        MutexLocker locker(m_mutex);
97        return (!m_suspended && !m_stopped);
98    }
99    ScriptExecutionContext* scriptExecutionContext()
100    {
101        MutexLocker locker(m_mutex);
102        return ActiveDOMObject::scriptExecutionContext();
103    }
104    Mutex& mutex() { return m_mutex; }
105
106private:
107    Mutex m_mutex;
108    bool m_suspended;
109    bool m_stopped;
110};
111
112static void destroyOnContextThread(PassOwnPtr<ActiveDOMObjectCallbackImpl> impl)
113{
114    OwnPtr<ActiveDOMObjectCallbackImpl> implOwnPtr = impl;
115
116    ScriptExecutionContext* context = implOwnPtr->scriptExecutionContext();
117    MutexLocker locker(implOwnPtr->mutex());
118    if (context && !context->isContextThread())
119        context->postTask(DestroyOnContextThreadTask::create(implOwnPtr.release()));
120}
121
122ActiveDOMCallback::ActiveDOMCallback(ScriptExecutionContext* context)
123    : m_impl(new ActiveDOMObjectCallbackImpl(context))
124{
125}
126
127ActiveDOMCallback::~ActiveDOMCallback()
128{
129    destroyOnContextThread(m_impl.release());
130}
131
132bool ActiveDOMCallback::canInvokeCallback() const
133{
134    return m_impl->canInvokeCallback();
135}
136
137ScriptExecutionContext* ActiveDOMCallback::scriptExecutionContext() const
138{
139    return m_impl->scriptExecutionContext();
140}
141
142} // namespace WebCore
143