Add refcount and scoped_refptr.

git-svn-id: http://webrtc.googlecode.com/svn/trunk@835 4adac7df-926f-26a2-2b94-8c16560cd09d

third_party_mods/libjingle/source/talk/base/refcount.h

@@ -0,0 +1,89 @@
+/*
+ * libjingle
+ * Copyright 2011, Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *  2. 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.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 TALK_BASE_REF_COUNT_H_
+#define TALK_BASE_REF_COUNT_H_
+
+#include <cstring>
+
+#include "talk/base/criticalsection.h"
+
+namespace talk_base {
+
+// Reference count interface.
+class RefCountInterface {
+ public:
+  virtual int AddRef() = 0;
+  virtual int Release() = 0;
+};
+
+template <class T>
+class RefCountedObject : public T {
+ public:
+  RefCountedObject() : ref_count_(0) {
+  }
+
+  template<typename P>
+  explicit RefCountedObject(P p) : ref_count_(0), T(p) {
+  }
+
+  template<typename P1, typename P2>
+  RefCountedObject(P1 p1, P2 p2) : ref_count_(0), T(p1, p2) {
+  }
+
+  template<typename P1, typename P2, typename P3>
+  RefCountedObject(P1 p1, P2 p2, P3 p3) : ref_count_(0), T(p1, p2, p3) {
+  }
+
+  template<typename P1, typename P2, typename P3, typename P4>
+  RefCountedObject(P1 p1, P2 p2, P3 p3, P4 p4) : ref_count_(0), T(p1, p2, p3, p4) {
+  }
+
+  template<typename P1, typename P2, typename P3, typename P4, typename P5>
+  RefCountedObject(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5)
+      : ref_count_(0), T(p1, p2, p3, p4, p5) {
+  }
+
+  virtual int AddRef() {
+    return talk_base::AtomicOps::Increment(&ref_count_);
+  }
+
+  virtual int Release() {
+    int count = talk_base::AtomicOps::Decrement(&ref_count_);
+    if (!count) {
+      delete this;
+    }
+    return count;
+  }
+
+ protected:
+  int ref_count_;
+};
+
+}  // namespace talk_base
+
+#endif  // TALK_BASE_REF_COUNT_H_

third_party_mods/libjingle/source/talk/base/scoped_refptr.h

@@ -0,0 +1,132 @@
+#ifndef TALK_BASE_SCOPED_REFPTR_H_
+#define TALK_BASE_SCOPED_REFPTR_H_
+// Originally these classes are copied from Chromium.
+
+//
+// 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 RefCounted<MyFoo> {
+//    ...
+//   };
+//
+//   void some_function() {
+//     scoped_refptr<MyFoo> foo = new MyFoo();
+//     foo->Method(param);
+//     // |foo| is released when this function returns
+//   }
+//
+//   void some_other_function() {
+//     scoped_refptr<MyFoo> foo = new MyFoo();
+//     ...
+//     foo = NULL;  // explicitly releases |foo|
+//     ...
+//     if (foo)
+//       foo->Method(param);
+//   }
+//
+// The above examples show how scoped_refptr<T> acts like a pointer to T.
+// Given two scoped_refptr<T> classes, it is also possible to exchange
+// references between the two objects, like so:
+//
+//   {
+//     scoped_refptr<MyFoo> a = new MyFoo();
+//     scoped_refptr<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:
+//
+//   {
+//     scoped_refptr<MyFoo> a = new MyFoo();
+//     scoped_refptr<MyFoo> b;
+//
+//     b = a;
+//     // now, |a| and |b| each own a reference to the same MyFoo object.
+//   }
+//
+namespace talk_base {
+
+template <class T>
+class scoped_refptr {
+ public:
+  scoped_refptr() : ptr_(NULL) {
+  }
+
+  scoped_refptr(T* p) : ptr_(p) {
+    if (ptr_)
+      ptr_->AddRef();
+  }
+
+  scoped_refptr(const scoped_refptr<T>& r) : ptr_(r.ptr_) {
+    if (ptr_)
+      ptr_->AddRef();
+  }
+
+  template <typename U>
+  scoped_refptr(const scoped_refptr<U>& r) : ptr_(r.get()) {
+    if (ptr_)
+      ptr_->AddRef();
+  }
+
+  ~scoped_refptr() {
+    if (ptr_)
+      ptr_->Release();
+  }
+
+  T* get() const { return ptr_; }
+  operator T*() const { return ptr_; }
+  T* operator->() const { return ptr_; }
+
+  // Release a pointer.
+  // The return value is the current pointer held by this object.
+  // If this object holds a NULL pointer, the return value is NULL.
+  // After this operation, this object will hold a NULL pointer,
+  // and will not own the object any more.
+  T* release() {
+    T* retVal = ptr_;
+    ptr_ = NULL;
+    return retVal;
+  }
+
+  scoped_refptr<T>& operator=(T* p) {
+    // AddRef first so that self assignment should work
+    if (p)
+      p->AddRef();
+    if (ptr_ )
+      ptr_ ->Release();
+    ptr_ = p;
+    return *this;
+  }
+
+  scoped_refptr<T>& operator=(const scoped_refptr<T>& r) {
+    return *this = r.ptr_;
+  }
+
+  template <typename U>
+  scoped_refptr<T>& operator=(const scoped_refptr<U>& r) {
+    return *this = r.get();
+  }
+
+  void swap(T** pp) {
+    T* p = ptr_;
+    ptr_ = *pp;
+    *pp = p;
+  }
+
+  void swap(scoped_refptr<T>& r) {
+    swap(&r.ptr_);
+  }
+
+ protected:
+  T* ptr_;
+};
+
+}  // namespace talk_base
+
+#endif  // TALK_BASE_SCOPED_REFPTR_H_