1/*
2 * Copyright (C) 2004 Apple Computer, 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 "runtime_root.h"
28
29#include "BridgeJSC.h"
30#include "runtime_object.h"
31#include <runtime/JSGlobalObject.h>
32#include <wtf/HashCountedSet.h>
33#include <wtf/HashSet.h>
34#include <wtf/StdLibExtras.h>
35
36namespace JSC { namespace Bindings {
37
38// This code attempts to solve two problems: (1) plug-ins leaking references to
39// JS and the DOM; (2) plug-ins holding stale references to JS and the DOM. Previous
40// comments in this file claimed that problem #1 was an issue in Java, in particular,
41// because Java, allegedly, didn't always call finalize when collecting an object.
42
43typedef HashSet<RootObject*> RootObjectSet;
44
45static RootObjectSet* rootObjectSet()
46{
47    DEFINE_STATIC_LOCAL(RootObjectSet, staticRootObjectSet, ());
48    return &staticRootObjectSet;
49}
50
51// FIXME:  These two functions are a potential performance problem.  We could
52// fix them by adding a JSObject to RootObject dictionary.
53
54RootObject* findProtectingRootObject(JSObject* jsObject)
55{
56    RootObjectSet::const_iterator end = rootObjectSet()->end();
57    for (RootObjectSet::const_iterator it = rootObjectSet()->begin(); it != end; ++it) {
58        if ((*it)->gcIsProtected(jsObject))
59            return *it;
60    }
61    return 0;
62}
63
64RootObject* findRootObject(JSGlobalObject* globalObject)
65{
66    RootObjectSet::const_iterator end = rootObjectSet()->end();
67    for (RootObjectSet::const_iterator it = rootObjectSet()->begin(); it != end; ++it) {
68        if ((*it)->globalObject() == globalObject)
69            return *it;
70    }
71    return 0;
72}
73
74RootObject::InvalidationCallback::~InvalidationCallback()
75{
76}
77
78PassRefPtr<RootObject> RootObject::create(const void* nativeHandle, JSGlobalObject* globalObject)
79{
80    return adoptRef(new RootObject(nativeHandle, globalObject));
81}
82
83RootObject::RootObject(const void* nativeHandle, JSGlobalObject* globalObject)
84    : m_isValid(true)
85    , m_nativeHandle(nativeHandle)
86    , m_globalObject(globalObject->globalData(), globalObject)
87{
88    ASSERT(globalObject);
89    rootObjectSet()->add(this);
90}
91
92RootObject::~RootObject()
93{
94    if (m_isValid)
95        invalidate();
96}
97
98void RootObject::invalidate()
99{
100    if (!m_isValid)
101        return;
102
103    {
104        WeakGCMap<RuntimeObject*, RuntimeObject>::iterator end = m_runtimeObjects.end();
105        for (WeakGCMap<RuntimeObject*, RuntimeObject>::iterator it = m_runtimeObjects.begin(); it != end; ++it) {
106            it.get().second->invalidate();
107        }
108
109        m_runtimeObjects.clear();
110    }
111
112    m_isValid = false;
113
114    m_nativeHandle = 0;
115    m_globalObject.clear();
116
117    {
118        HashSet<InvalidationCallback*>::iterator end = m_invalidationCallbacks.end();
119        for (HashSet<InvalidationCallback*>::iterator iter = m_invalidationCallbacks.begin(); iter != end; ++iter)
120            (**iter)(this);
121
122        m_invalidationCallbacks.clear();
123    }
124
125    ProtectCountSet::iterator end = m_protectCountSet.end();
126    for (ProtectCountSet::iterator it = m_protectCountSet.begin(); it != end; ++it)
127        JSC::gcUnprotect(it->first);
128    m_protectCountSet.clear();
129
130    rootObjectSet()->remove(this);
131}
132
133void RootObject::gcProtect(JSObject* jsObject)
134{
135    ASSERT(m_isValid);
136
137    if (!m_protectCountSet.contains(jsObject))
138        JSC::gcProtect(jsObject);
139    m_protectCountSet.add(jsObject);
140}
141
142void RootObject::gcUnprotect(JSObject* jsObject)
143{
144    ASSERT(m_isValid);
145
146    if (!jsObject)
147        return;
148
149    if (m_protectCountSet.count(jsObject) == 1)
150        JSC::gcUnprotect(jsObject);
151    m_protectCountSet.remove(jsObject);
152}
153
154bool RootObject::gcIsProtected(JSObject* jsObject)
155{
156    ASSERT(m_isValid);
157    return m_protectCountSet.contains(jsObject);
158}
159
160const void* RootObject::nativeHandle() const
161{
162    ASSERT(m_isValid);
163    return m_nativeHandle;
164}
165
166JSGlobalObject* RootObject::globalObject() const
167{
168    ASSERT(m_isValid);
169    return m_globalObject.get();
170}
171
172void RootObject::updateGlobalObject(JSGlobalObject* globalObject)
173{
174    m_globalObject.set(globalObject->globalData(), globalObject);
175}
176
177void RootObject::addRuntimeObject(JSGlobalData& globalData, RuntimeObject* object)
178{
179    ASSERT(m_isValid);
180    ASSERT(!m_runtimeObjects.get(object));
181
182    m_runtimeObjects.set(globalData, object, object);
183}
184
185void RootObject::removeRuntimeObject(RuntimeObject* object)
186{
187    if (!m_isValid)
188        return;
189
190    ASSERT(m_runtimeObjects.get(object));
191
192    m_runtimeObjects.take(object);
193}
194
195} } // namespace JSC::Bindings
196