cef/include/cef_base.h

158 lines
5.2 KiB
C++

// Copyright (c) 2012 Marshall A. Greenblatt. All rights reserved.
//
// 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.
#ifndef CEF_INCLUDE_CEF_BASE_H_
#define CEF_INCLUDE_CEF_BASE_H_
#pragma once
#include "include/base/cef_atomic_ref_count.h"
#include "include/base/cef_build.h"
#include "include/base/cef_macros.h"
// Bring in common C++ type definitions used by CEF consumers.
#include "include/internal/cef_ptr.h"
#include "include/internal/cef_time_wrappers.h"
#include "include/internal/cef_types_wrappers.h"
#if defined(OS_WIN)
#include "include/internal/cef_win.h"
#elif defined(OS_MAC)
#include "include/internal/cef_mac.h"
#elif defined(OS_LINUX)
#include "include/internal/cef_linux.h"
#endif
///
/// All ref-counted framework classes must extend this class.
///
class CefBaseRefCounted {
public:
///
/// Called to increment the reference count for the object. Should be called
/// for every new copy of a pointer to a given object.
///
virtual void AddRef() const = 0;
///
/// Called to decrement the reference count for the object. Returns true if
/// the reference count is 0, in which case the object should self-delete.
///
virtual bool Release() const = 0;
///
/// Returns true if the reference count is 1.
///
virtual bool HasOneRef() const = 0;
///
/// Returns true if the reference count is at least 1.
///
virtual bool HasAtLeastOneRef() const = 0;
protected:
virtual ~CefBaseRefCounted() {}
};
///
/// All scoped framework classes must extend this class.
///
class CefBaseScoped {
public:
virtual ~CefBaseScoped() {}
};
///
/// Class that implements atomic reference counting.
///
class CefRefCount {
public:
CefRefCount() = default;
CefRefCount(const CefRefCount&) = delete;
CefRefCount& operator=(const CefRefCount&) = delete;
///
/// Increment the reference count.
///
void AddRef() const { ref_count_.Increment(); }
///
/// Decrement the reference count. Returns true if the reference count is 0.
///
bool Release() const { return !ref_count_.Decrement(); }
///
/// Returns true if the reference count is 1.
///
bool HasOneRef() const { return ref_count_.IsOne(); }
///
/// Returns true if the reference count is at least 1.
///
bool HasAtLeastOneRef() const { return !ref_count_.IsZero(); }
///
/// Returns the current reference count (with no barriers). This is subtle,
/// and should be used only for debugging.
///
int SubtleRefCountForDebug() const {
return ref_count_.SubtleRefCountForDebug();
}
private:
mutable base::AtomicRefCount ref_count_{0};
};
///
/// Macro that provides a reference counting implementation for classes
/// extending CefBase.
///
#define IMPLEMENT_REFCOUNTING(ClassName) \
public: \
void AddRef() const override { \
ref_count_.AddRef(); \
} \
bool Release() const override { \
if (ref_count_.Release()) { \
delete static_cast<const ClassName*>(this); \
return true; \
} \
return false; \
} \
bool HasOneRef() const override { \
return ref_count_.HasOneRef(); \
} \
bool HasAtLeastOneRef() const override { \
return ref_count_.HasAtLeastOneRef(); \
} \
\
private: \
CefRefCount ref_count_
#endif // CEF_INCLUDE_CEF_BASE_H_