cef/include/cef_base.h

195 lines
7.1 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_types_wrappers.h"
#if defined(OS_WIN)
#include "include/internal/cef_win.h"
#elif defined(OS_MACOSX)
#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() : ref_count_(0) {}
///
// Increment the reference count.
///
void AddRef() const { base::AtomicRefCountInc(&ref_count_); }
///
// Decrement the reference count. Returns true if the reference count is 0.
///
bool Release() const { return !base::AtomicRefCountDec(&ref_count_); }
///
// Returns true if the reference count is 1.
///
bool HasOneRef() const { return base::AtomicRefCountIsOne(&ref_count_); }
///
// Returns true if the reference count is at least 1.
///
bool HasAtLeastOneRef() const {
return !base::AtomicRefCountIsZero(&ref_count_);
}
private:
mutable base::AtomicRefCount ref_count_;
DISALLOW_COPY_AND_ASSIGN(CefRefCount);
};
///
// 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_;
///
// Macro that provides a locking implementation. Use the Lock() and Unlock()
// methods to protect a section of code from simultaneous access by multiple
// threads. The AutoLock class is a helper that will hold the lock while in
// scope.
//
// THIS MACRO IS DEPRECATED. Use an explicit base::Lock member variable and
// base::AutoLock instead. For example:
//
// #include "include/base/cef_lock.h"
//
// // Class declaration.
// class MyClass : public CefBaseRefCounted {
// public:
// MyClass() : value_(0) {}
// // Method that may be called on multiple threads.
// void IncrementValue();
// private:
// // Value that may be accessed on multiple theads.
// int value_;
// // Lock used to protect access to |value_|.
// base::Lock lock_;
// IMPLEMENT_REFCOUNTING(MyClass);
// };
//
// // Class implementation.
// void MyClass::IncrementValue() {
// // Acquire the lock for the scope of this method.
// base::AutoLock lock_scope(lock_);
// // |value_| can now be modified safely.
// value_++;
// }
///
#define IMPLEMENT_LOCKING(ClassName) \
public: \
class AutoLock { \
public: \
explicit AutoLock(ClassName* base) : base_(base) { base_->Lock(); } \
~AutoLock() { base_->Unlock(); } \
\
private: \
ClassName* base_; \
DISALLOW_COPY_AND_ASSIGN(AutoLock); \
}; \
void Lock() { lock_.Acquire(); } \
void Unlock() { lock_.Release(); } \
\
private: \
base::Lock lock_;
#endif // CEF_INCLUDE_CEF_BASE_H_