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// Copyright (c) 2014 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_INTERNAL_CEF_PTR_H_ #define CEF_INCLUDE_INTERNAL_CEF_PTR_H_ #pragma once #include "include/base/cef_build.h" #include "include/base/cef_ref_counted.h" #if defined(USING_CHROMIUM_INCLUDES) #include // For std::unique_ptr. #else #include "include/base/cef_scoped_ptr.h" #endif /// // Smart pointer implementation that is an alias of scoped_refptr from // include/base/cef_ref_counted.h. //

// A smart pointer class for reference counted objects. Use this class instead // of calling AddRef and Release manually on a reference counted object to // avoid common memory leaks caused by forgetting to Release an object // reference. Sample usage: //

//   class MyFoo : public CefBaseRefCounted {
//    ...
//   };
//
//   void some_function() {
//     // The MyFoo object that |foo| represents starts with a single
//     // reference.
//     CefRefPtr<MyFoo> foo = new MyFoo();
//     foo->Method(param);
//     // |foo| is released when this function returns
//   }
//
//   void some_other_function() {
//     CefRefPtr<MyFoo> foo = new MyFoo();
//     ...
//     foo = NULL;  // explicitly releases |foo|
//     ...
//     if (foo)
//       foo->Method(param);
//   }
//

// The above examples show how CefRefPtr<T> acts like a pointer to T. // Given two CefRefPtr<T> classes, it is also possible to exchange // references between the two objects, like so: //

//   {
//     CefRefPtr<MyFoo> a = new MyFoo();
//     CefRefPtr<MyFoo> b;
//
//     b.swap(a);
//     // now, |b| references the MyFoo object, and |a| references NULL.
//   }
//

// To make both |a| and |b| in the above example reference the same MyFoo // object, simply use the assignment operator: //

//   {
//     CefRefPtr<MyFoo> a = new MyFoo();
//     CefRefPtr<MyFoo> b;
//
//     b = a;
//     // now, |a| and |b| each own a reference to the same MyFoo object.
//     // the reference count of the underlying MyFoo object will be 2.
//   }
//

// Reference counted objects can also be passed as function parameters and // used as function return values: //

//   void some_func_with_param(CefRefPtr<MyFoo> param) {
//     // A reference is added to the MyFoo object that |param| represents
//     // during the scope of some_func_with_param() and released when
//     // some_func_with_param() goes out of scope.
//   }
//
//   CefRefPtr<MyFoo> some_func_with_retval() {
//     // The MyFoo object that |foox| represents starts with a single
//     // reference.
//     CefRefPtr<MyFoo> foox = new MyFoo();
//
//     // Creating the return value adds an additional reference.
//     return foox;
//
//     // When some_func_with_retval() goes out of scope the original |foox|
//     // reference is released.
//   }
//
//   void and_another_function() {
//     CefRefPtr<MyFoo> foo = new MyFoo();
//
//     // pass |foo| as a parameter.
//     some_function(foo);
//
//     CefRefPtr<MyFoo> foo2 = some_func_with_retval();
//     // Now, since we kept a reference to the some_func_with_retval() return
//     // value, |foo2| is the only class pointing to the MyFoo object created
//     in some_func_with_retval(), and it has a reference count of 1.
//
//     some_func_with_retval();
//     // Now, since we didn't keep a reference to the some_func_with_retval()
//     // return value, the MyFoo object created in some_func_with_retval()
//     // will automatically be released.
//   }
//

// And in standard containers: //

//   {
//      // Create a vector that holds MyFoo objects.
//      std::vector<CefRefPtr<MyFoo> > MyFooVec;
//
//     // The MyFoo object that |foo| represents starts with a single
//     // reference.
//     CefRefPtr<MyFoo> foo = new MyFoo();
//
//     // When the MyFoo object is added to |MyFooVec| the reference count
//     // is increased to 2.
//     MyFooVec.push_back(foo);
//   }
//

/// #if defined(HAS_CPP11_TEMPLATE_ALIAS_SUPPORT) template using CefRefPtr = scoped_refptr; #else // When template aliases are not supported use a define instead of subclassing // because it's otherwise hard to get the constructors to behave correctly. #define CefRefPtr scoped_refptr #endif /// // A CefOwnPtr is like a T*, except that the destructor of CefOwnPtr // automatically deletes the pointer it holds (if any). That is, CefOwnPtr // owns the T object that it points to. Like a T*, a CefOwnPtr may hold // either NULL or a pointer to a T object. Also like T*, CefOwnPtr is // thread-compatible, and once you dereference it, you get the thread safety // guarantees of T. /// #if defined(USING_CHROMIUM_INCLUDES) // Implementation-side code uses std::unique_ptr instead of scoped_ptr. template > using CefOwnPtr = std::unique_ptr; #elif defined(HAS_CPP11_TEMPLATE_ALIAS_SUPPORT) template > using CefOwnPtr = scoped_ptr; #else // When template aliases are not supported use a define instead of subclassing // because it's otherwise hard to get the constructors to behave correctly. #define CefOwnPtr scoped_ptr #endif /// // A CefRawPtr is the same as T* /// #if defined(HAS_CPP11_TEMPLATE_ALIAS_SUPPORT) #define CEF_RAW_PTR_GET(r) r template using CefRawPtr = T*; #else // Simple wrapper implementation that behaves as much like T* as possible. // CEF_RAW_PTR_GET is required for VS2008 compatibility (Issue #2155). #define CEF_RAW_PTR_GET(r) r.get() template class CefRawPtr { public: CefRawPtr() : ptr_(nullptr) {} CefRawPtr(T* p) : ptr_(p) {} CefRawPtr(const CefRawPtr& r) : ptr_(r.ptr_) {} template CefRawPtr(const CefRawPtr& r) : ptr_(r.get()) {} T* get() const { return ptr_; } // Allow CefRawPtr to be used in boolean expression and comparison operations. operator T*() const { return ptr_; } T* operator->() const { assert(ptr_ != NULL); return ptr_; } CefRawPtr& operator=(T* p) { ptr_ = p; return *this; } CefRawPtr& operator=(const CefRawPtr& r) { return *this = r.ptr_; } template CefRawPtr& operator=(const CefRawPtr& r) { return *this = r.get(); } private: T* ptr_; }; #endif #endif // CEF_INCLUDE_INTERNAL_CEF_PTR_H_

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