Home | History | Annotate | Download | only in lib 
      1 // Copyright 2014 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_SHARED_PTR_H_
      6 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_SHARED_PTR_H_
      7 
      8 #include "mojo/public/cpp/bindings/lib/shared_data.h"
      9 
     10 namespace mojo {
     11 namespace internal {
     12 
     13 // Used to manage a heap-allocated instance of P that can be shared via
     14 // reference counting. When the last reference is dropped, the instance is
     15 // deleted.
     16 template <typename P>
     17 class SharedPtr {
     18  public:
     19   SharedPtr() {}
     20 
     21   explicit SharedPtr(P* ptr) {
     22     impl_.mutable_value()->ptr = ptr;
     23   }
     24 
     25   // Default copy-constructor and assignment operator are OK.
     26 
     27   P* get() {
     28     return impl_.value().ptr;
     29   }
     30   const P* get() const {
     31     return impl_.value().ptr;
     32   }
     33 
     34   P* operator->() { return get(); }
     35   const P* operator->() const { return get(); }
     36 
     37  private:
     38   class Impl {
     39    public:
     40     ~Impl() {
     41       if (ptr)
     42         delete ptr;
     43     }
     44 
     45     Impl() : ptr(NULL) {
     46     }
     47 
     48     Impl(P* ptr) : ptr(ptr) {
     49     }
     50 
     51     P* ptr;
     52 
     53    private:
     54     MOJO_DISALLOW_COPY_AND_ASSIGN(Impl);
     55   };
     56 
     57   SharedData<Impl> impl_;
     58 };
     59 
     60 }  // namespace mojo
     61 }  // namespace internal
     62 
     63 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_SHARED_PTR_H_
     64