cefpython/src/include/base/cef_atomic_ref_count.h at cefpython66 · 2php/cefpython · GitHub

Repository navigation

History

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

152

153

154

155

156

157

158

159

160

161

162

163

164

165

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

// * Redistributions of source code must retain the above copyright

// notice, this list of conditions and the following disclaimer.

// * Redistributions in binary form must reproduce the above

// copyright notice, this list of conditions and the following disclaimer

// in the documentation and/or other materials provided with the

// distribution.

// * Neither the name of Google Inc. nor the name Chromium Embedded

// Framework nor the names of its contributors may be used to endorse

// or promote products derived from this software without specific prior

// written permission.

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// This is a low level implementation of atomic semantics for reference

// counting. Please use cef_ref_counted.h directly instead.

// The Chromium implementation includes annotations to avoid some false

// positives when using data race detection tools. Annotations are not

// currently supported by the CEF implementation.

#ifndef CEF_INCLUDE_BASE_CEF_ATOMIC_REF_COUNT_H_

#define CEF_INCLUDE_BASE_CEF_ATOMIC_REF_COUNT_H_

#pragma once

#if defined(USING_CHROMIUM_INCLUDES)

// When building CEF include the Chromium header directly.

#include "base/atomic_ref_count.h"

// Used when declaring a base::AtomicRefCount value. This is an object type with

// Chromium headers.

#define ATOMIC_DECLARATION (0)

// Maintaining compatibility with AtompicRefCount* functions that were removed

// from Chromium in http://crrev.com/ee96d561.

namespace base {

// Increment a reference count by 1.

inline void AtomicRefCountInc(volatile AtomicRefCount* ptr) {

const_cast<AtomicRefCount*>(ptr)->Increment();

}

// Decrement a reference count by 1 and return whether the result is non-zero.

// Insert barriers to ensure that state written before the reference count

// became zero will be visible to a thread that has just made the count zero.

inline bool AtomicRefCountDec(volatile AtomicRefCount* ptr) {

return const_cast<AtomicRefCount*>(ptr)->Decrement();

}

// Return whether the reference count is one. If the reference count is used

// in the conventional way, a refrerence count of 1 implies that the current

// thread owns the reference and no other thread shares it. This call performs

// the test for a reference count of one, and performs the memory barrier

// needed for the owning thread to act on the object, knowing that it has

// exclusive access to the object.

inline bool AtomicRefCountIsOne(volatile AtomicRefCount* ptr) {

return const_cast<AtomicRefCount*>(ptr)->IsOne();

}

// Return whether the reference count is zero. With conventional object

// referencing counting, the object will be destroyed, so the reference count

// should never be zero. Hence this is generally used for a debug check.

inline bool AtomicRefCountIsZero(volatile AtomicRefCount* ptr) {

return const_cast<AtomicRefCount*>(ptr)->IsZero();

}

} // namespace base

#else // !USING_CHROMIUM_INCLUDES

// The following is substantially similar to the Chromium implementation.

// If the Chromium implementation diverges the below implementation should be

// updated to match.

#include "include/base/cef_atomicops.h"

// Annotations are not currently supported.

#define ANNOTATE_HAPPENS_BEFORE(obj) /* empty */

#define ANNOTATE_HAPPENS_AFTER(obj) /* empty */

// Used when declaring a base::AtomicRefCount value. This is an integer/ptr type

// with CEF headers.

#define ATOMIC_DECLARATION = 0

namespace base {

typedef subtle::Atomic32 AtomicRefCount;

// Increment a reference count by "increment", which must exceed 0.

inline void AtomicRefCountIncN(volatile AtomicRefCount* ptr,

AtomicRefCount increment) {

subtle::NoBarrier_AtomicIncrement(ptr, increment);

}

// Decrement a reference count by "decrement", which must exceed 0,

// and return whether the result is non-zero.

// Insert barriers to ensure that state written before the reference count

// became zero will be visible to a thread that has just made the count zero.

inline bool AtomicRefCountDecN(volatile AtomicRefCount* ptr,

AtomicRefCount decrement) {

ANNOTATE_HAPPENS_BEFORE(ptr);

bool res = (subtle::Barrier_AtomicIncrement(ptr, -decrement) != 0);

if (!res) {

ANNOTATE_HAPPENS_AFTER(ptr);

}

return res;

}

// Increment a reference count by 1.

inline void AtomicRefCountInc(volatile AtomicRefCount* ptr) {

base::AtomicRefCountIncN(ptr, 1);

}

// Decrement a reference count by 1 and return whether the result is non-zero.

// Insert barriers to ensure that state written before the reference count

// became zero will be visible to a thread that has just made the count zero.

inline bool AtomicRefCountDec(volatile AtomicRefCount* ptr) {

return base::AtomicRefCountDecN(ptr, 1);

}

// Return whether the reference count is one. If the reference count is used

// in the conventional way, a refrerence count of 1 implies that the current

// thread owns the reference and no other thread shares it. This call performs

// the test for a reference count of one, and performs the memory barrier

// needed for the owning thread to act on the object, knowing that it has

// exclusive access to the object.

inline bool AtomicRefCountIsOne(volatile AtomicRefCount* ptr) {

bool res = (subtle::Acquire_Load(ptr) == 1);

if (res) {

ANNOTATE_HAPPENS_AFTER(ptr);

}

return res;

}

// Return whether the reference count is zero. With conventional object

// referencing counting, the object will be destroyed, so the reference count

// should never be zero. Hence this is generally used for a debug check.

inline bool AtomicRefCountIsZero(volatile AtomicRefCount* ptr) {

bool res = (subtle::Acquire_Load(ptr) == 0);

if (res) {

ANNOTATE_HAPPENS_AFTER(ptr);

}

return res;

}

} // namespace base

#endif // !USING_CHROMIUM_INCLUDES

#endif // CEF_INCLUDE_BASE_CEF_ATOMIC_REF_COUNT_H_

cefpython/src/include/base/cef_atomic_ref_count.h at cefpython66 · 2php/cefpython · GitHub

Repository navigation

Expand file tree

Breadcrumbs

cef_atomic_ref_count.h

Latest commit

History

Breadcrumbs

cef_atomic_ref_count.h

File metadata and controls