1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// nsWeakReference.cpp
#include "mozilla/Attributes.h"
#include "nsWeakReference.h"
#include "nsCOMPtr.h"
#include "nsDebug.h"
class nsWeakReference final : public nsIWeakReference {
public:
// nsISupports...
NS_DECL_ISUPPORTS
// nsIWeakReference...
NS_DECL_NSIWEAKREFERENCE
private:
friend class nsSupportsWeakReference;
explicit nsWeakReference(nsSupportsWeakReference* aReferent)
: nsIWeakReference(aReferent)
// ...I can only be constructed by an |nsSupportsWeakReference|
{}
~nsWeakReference()
// ...I will only be destroyed by calling |delete| myself.
{
MOZ_WEAKREF_ASSERT_OWNINGTHREAD;
if (mObject) {
static_cast<nsSupportsWeakReference*>(mObject)->NoticeProxyDestruction();
}
}
void NoticeReferentDestruction()
// ...called (only) by an |nsSupportsWeakReference| from _its_ dtor.
{
MOZ_WEAKREF_ASSERT_OWNINGTHREAD;
mObject = nullptr;
}
};
nsresult nsQueryReferent::operator()(const nsIID& aIID, void** aAnswer) const {
nsresult status;
if (mWeakPtr) {
if (NS_FAILED(status = mWeakPtr->QueryReferent(aIID, aAnswer))) {
*aAnswer = 0;
}
} else {
status = NS_ERROR_NULL_POINTER;
}
if (mErrorPtr) {
*mErrorPtr = status;
}
return status;
}
nsIWeakReference* NS_GetWeakReference(nsISupportsWeakReference* aInstancePtr,
nsresult* aErrorPtr) {
nsresult status;
nsIWeakReference* result = nullptr;
if (aInstancePtr) {
status = aInstancePtr->GetWeakReference(&result);
} else {
status = NS_ERROR_NULL_POINTER;
}
if (aErrorPtr) {
*aErrorPtr = status;
}
return result;
}
nsIWeakReference* // or else |already_AddRefed<nsIWeakReference>|
NS_GetWeakReference(nsISupports* aInstancePtr, nsresult* aErrorPtr) {
nsresult status;
nsIWeakReference* result = nullptr;
if (aInstancePtr) {
nsCOMPtr<nsISupportsWeakReference> factoryPtr =
do_QueryInterface(aInstancePtr, &status);
if (factoryPtr) {
status = factoryPtr->GetWeakReference(&result);
}
// else, |status| has already been set by |do_QueryInterface|
} else {
status = NS_ERROR_NULL_POINTER;
}
if (aErrorPtr) {
*aErrorPtr = status;
}
return result;
}
nsresult nsSupportsWeakReference::GetWeakReference(
nsIWeakReference** aInstancePtr) {
if (!aInstancePtr) {
return NS_ERROR_NULL_POINTER;
}
if (!mProxy) {
mProxy = new nsWeakReference(this);
} else {
MOZ_WEAKREF_ASSERT_OWNINGTHREAD_DELEGATED(mProxy);
}
RefPtr<nsWeakReference> rval = mProxy;
rval.forget(aInstancePtr);
return NS_OK;
}
NS_IMPL_ISUPPORTS(nsWeakReference, nsIWeakReference)
NS_IMETHODIMP
nsWeakReference::QueryReferentFromScript(const nsIID& aIID,
void** aInstancePtr) {
return QueryReferent(aIID, aInstancePtr);
}
nsresult nsIWeakReference::QueryReferent(const nsIID& aIID,
void** aInstancePtr) {
MOZ_WEAKREF_ASSERT_OWNINGTHREAD;
if (!mObject) {
return NS_ERROR_NULL_POINTER;
}
return mObject->QueryInterface(aIID, aInstancePtr);
}
size_t nsWeakReference::SizeOfOnlyThis(mozilla::MallocSizeOf aMallocSizeOf) {
return aMallocSizeOf(this);
}
void nsSupportsWeakReference::ClearWeakReferences() {
if (mProxy) {
mProxy->NoticeReferentDestruction();
mProxy = nullptr;
}
}
|
