Line data    Source code

       1              : /*
       2              :  *
       3              :  *    Copyright (c) 2025 Project CHIP Authors
       4              :  *
       5              :  *    Licensed under the Apache License, Version 2.0 (the "License");
       6              :  *    you may not use this file except in compliance with the License.
       7              :  *    You may obtain a copy of the License at
       8              :  *
       9              :  *        http://www.apache.org/licenses/LICENSE-2.0
      10              :  *
      11              :  *    Unless required by applicable law or agreed to in writing, software
      12              :  *    distributed under the License is distributed on an "AS IS" BASIS,
      13              :  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      14              :  *    See the License for the specific language governing permissions and
      15              :  *    limitations under the License.
      16              :  */
      17              : 
      18              : /**
      19              :  *    @file
      20              :  *          Contains a standard RAII class which calls Release on dtor.
      21              :  */
      22              : 
      23              : #pragma once
      24              : 
      25              : #include <lib/support/CodeUtils.h>
      26              : #include <stddef.h>
      27              : 
      28              : namespace chip {
      29              : 
      30              : /// RAII class for iterators that guarantees that Release() will be called
      31              : /// on the underlying type.  This is effectively a simple unique_ptr, except
      32              : /// calling Release instead of delete
      33              : /// See also ReferenceCountedPtr<T>, which automatically retains a ReferenceCounted
      34              : template <typename Releasable>
      35              : class AutoRelease
      36              : {
      37              : public:
      38           11 :     AutoRelease(Releasable * releasable) : mReleasable(releasable) {}
      39           11 :     ~AutoRelease() { Release(); }
      40              : 
      41              :     // Not copyable or movable
      42              :     AutoRelease(const AutoRelease &)             = delete;
      43              :     AutoRelease(const AutoRelease &&)            = delete;
      44              :     AutoRelease & operator=(const AutoRelease &) = delete;
      45              : 
      46           10 :     inline Releasable * operator->() { return mReleasable; }
      47              :     inline const Releasable * operator->() const { return mReleasable; }
      48              :     inline const Releasable & operator*() const { return *mReleasable; }
      49            3 :     inline Releasable & operator*() { return *mReleasable; }
      50              : 
      51              :     inline operator bool() { return mReleasable != nullptr; }
      52           11 :     inline bool IsNull() const { return mReleasable == nullptr; }
      53              : 
      54           23 :     void Release()
      55              :     {
      56           23 :         VerifyOrReturn(mReleasable != nullptr);
      57           12 :         mReleasable->Release();
      58           12 :         mReleasable = nullptr;
      59              :     }
      60              : 
      61            3 :     void Set(Releasable * releasable)
      62              :     {
      63            3 :         if (mReleasable != releasable)
      64              :         {
      65            2 :             Release();
      66            2 :             mReleasable = releasable;
      67              :         }
      68            3 :     }
      69              : 
      70              : protected:
      71              :     Releasable * mReleasable = nullptr;
      72              : };
      73              : 
      74              : } // namespace chip