| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef BASE_WIN_SCOPED_COM_INITIALIZER_H_ |
| #define BASE_WIN_SCOPED_COM_INITIALIZER_H_ |
| |
| #include <objbase.h> |
| |
| #include "base/logging.h" |
| #include "base/macros.h" |
| #include "base/threading/thread_checker.h" |
| #include "build/build_config.h" |
| |
| namespace base { |
| namespace win { |
| |
| // Initializes COM in the constructor (STA or MTA), and uninitializes COM in the |
| // destructor. |
| // |
| // WARNING: This should only be used once per thread, ideally scoped to a |
| // similar lifetime as the thread itself. You should not be using this in |
| // random utility functions that make COM calls -- instead ensure these |
| // functions are running on a COM-supporting thread! |
| class ScopedCOMInitializer { |
| public: |
| // Enum value provided to initialize the thread as an MTA instead of STA. |
| enum SelectMTA { kMTA }; |
| |
| // Constructor for STA initialization. |
| ScopedCOMInitializer() { |
| Initialize(COINIT_APARTMENTTHREADED); |
| } |
| |
| // Constructor for MTA initialization. |
| explicit ScopedCOMInitializer(SelectMTA mta) { |
| Initialize(COINIT_MULTITHREADED); |
| } |
| |
| ~ScopedCOMInitializer() { |
| DCHECK_CALLED_ON_VALID_THREAD(thread_checker_); |
| if (succeeded()) |
| CoUninitialize(); |
| } |
| |
| bool succeeded() const { return SUCCEEDED(hr_); } |
| |
| private: |
| void Initialize(COINIT init) { |
| DCHECK_CALLED_ON_VALID_THREAD(thread_checker_); |
| hr_ = CoInitializeEx(NULL, init); |
| DCHECK_NE(RPC_E_CHANGED_MODE, hr_) << "Invalid COM thread model change"; |
| } |
| |
| HRESULT hr_; |
| THREAD_CHECKER(thread_checker_); |
| |
| DISALLOW_COPY_AND_ASSIGN(ScopedCOMInitializer); |
| }; |
| |
| } // namespace win |
| } // namespace base |
| |
| #endif // BASE_WIN_SCOPED_COM_INITIALIZER_H_ |