OpenShot Audio Library | OpenShotAudio: juce_SharedResourcePointer.h Source File

OpenShot Audio Library | OpenShotAudio 0.3.0

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juce_SharedResourcePointer.h
1/*
2 ==============================================================================
3
4 This file is part of the JUCE library.
5 Copyright (c) 2017 - ROLI Ltd.
6
7 JUCE is an open source library subject to commercial or open-source
8 licensing.
9
10 The code included in this file is provided under the terms of the ISC license
11 http://www.isc.org/downloads/software-support-policy/isc-license. Permission
12 To use, copy, modify, and/or distribute this software for any purpose with or
13 without fee is hereby granted provided that the above copyright notice and
14 this permission notice appear in all copies.
15
16 JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
17 EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
18 DISCLAIMED.
19
20 ==============================================================================
21*/
22
23namespace juce
24{
25
26//==============================================================================
80template <typename SharedObjectType>
81 class SharedResourcePointer
82{
83public:
90 SharedResourcePointer()
91 {
92 initialise();
93 }
94
95 SharedResourcePointer (const SharedResourcePointer&)
96 {
97 initialise();
98 }
99
104 ~SharedResourcePointer()
105 {
106 auto& holder = getSharedObjectHolder();
107 const SpinLock::ScopedLockType sl (holder.lock);
108
109 if (--(holder.refCount) == 0)
110 holder.sharedInstance = nullptr;
111 }
112
114 operator SharedObjectType*() const noexcept { return sharedObject; }
115
117 SharedObjectType& get() const noexcept { return *sharedObject; }
118
122 SharedObjectType& getObject() const noexcept { return *sharedObject; }
123
125 SharedObjectType* operator->() const noexcept { return sharedObject; }
126
128 int getReferenceCount() const noexcept { return getSharedObjectHolder().refCount; }
129
130private:
131 struct SharedObjectHolder
132 {
133 SpinLock lock;
134 std::unique_ptr<SharedObjectType> sharedInstance;
135 int refCount;
136 };
137
138 static SharedObjectHolder& getSharedObjectHolder() noexcept
139 {
140 static void* holder [(sizeof (SharedObjectHolder) + sizeof(void*) - 1) / sizeof(void*)] = { nullptr };
141 return *reinterpret_cast<SharedObjectHolder*> (holder);
142 }
143
144 SharedObjectType* sharedObject;
145
146 void initialise()
147 {
148 auto& holder = getSharedObjectHolder();
149 const SpinLock::ScopedLockType sl (holder.lock);
150
151 if (++(holder.refCount) == 1)
152 holder.sharedInstance.reset (new SharedObjectType());
153
154 sharedObject = holder.sharedInstance.get();
155 }
156
157 // There's no need to assign to a SharedResourcePointer because every
158 // instance of the class is exactly the same!
159 SharedResourcePointer& operator= (const SharedResourcePointer&) = delete;
160
161 JUCE_LEAK_DETECTOR (SharedResourcePointer)
162};
163
164} // namespace juce
juce::GenericScopedLock
Definition: juce_ScopedLock.h:55
juce::SharedResourcePointer
Definition: juce_SharedResourcePointer.h:82
juce::SharedResourcePointer::~SharedResourcePointer
~SharedResourcePointer()
Definition: juce_SharedResourcePointer.h:104
juce::SharedResourcePointer::getReferenceCount
int getReferenceCount() const noexcept
Definition: juce_SharedResourcePointer.h:128
juce::SharedResourcePointer::getObject
SharedObjectType & getObject() const noexcept
Definition: juce_SharedResourcePointer.h:122
juce::SharedResourcePointer::SharedResourcePointer
SharedResourcePointer()
Definition: juce_SharedResourcePointer.h:90
juce::SharedResourcePointer::get
SharedObjectType & get() const noexcept
Definition: juce_SharedResourcePointer.h:117
juce::SharedResourcePointer::operator->
SharedObjectType * operator->() const noexcept
Definition: juce_SharedResourcePointer.h:125
juce::SpinLock
Definition: juce_SpinLock.h:42
juce::SpinLock::ScopedLockType
GenericScopedLock< SpinLock > ScopedLockType
Definition: juce_SpinLock.h:73