Create 2272 release branch for CEF3.

git-svn-id: https://chromiumembedded.googlecode.com/svn/branches/2272@1993 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

include/cef_base.h

@@ -0,0 +1,180 @@
+// 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
+
+///
+// Interface defining the reference count implementation methods. All framework
+// classes must extend the CefBase class.
+///
+class CefBase {
+ 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;
+
+ protected:
+  virtual ~CefBase() {}
+};
+
+///
+// 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_);
+  }
+
+ 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 {                           \
+      ref_count_.AddRef();                          \
+    }                                               \
+    bool Release() const {                          \
+      if (ref_count_.Release()) {                   \
+        delete static_cast<const ClassName*>(this); \
+        return true;                                \
+      }                                             \
+      return false;                                 \
+    }                                               \
+    bool HasOneRef() const {                        \
+      return ref_count_.HasOneRef();                \
+    }                                               \
+  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 CefBase {
+//  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_