57 lines
1.9 KiB
C++
57 lines
1.9 KiB
C++
/*
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* Copyright (c) 2020 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef RTC_BASE_WIN_SCOPED_COM_INITIALIZER_H_
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#define RTC_BASE_WIN_SCOPED_COM_INITIALIZER_H_
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#include <comdef.h>
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namespace webrtc {
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// Initializes COM in the constructor (STA or MTA), and uninitializes COM in the
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// destructor. Taken from base::win::ScopedCOMInitializer.
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//
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// WARNING: This should only be used once per thread, ideally scoped to a
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// similar lifetime as the thread itself. You should not be using this in
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// random utility functions that make COM calls; instead ensure that these
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// functions are running on a COM-supporting thread!
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// See https://msdn.microsoft.com/en-us/library/ms809971.aspx for details.
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class ScopedCOMInitializer {
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public:
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// Enum value provided to initialize the thread as an MTA instead of STA.
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// There are two types of apartments, Single Threaded Apartments (STAs)
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// and Multi Threaded Apartments (MTAs). Within a given process there can
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// be multiple STA’s but there is only one MTA. STA is typically used by
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// "GUI applications" and MTA by "worker threads" with no UI message loop.
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enum SelectMTA { kMTA };
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// Constructor for STA initialization.
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ScopedCOMInitializer();
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// Constructor for MTA initialization.
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explicit ScopedCOMInitializer(SelectMTA mta);
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~ScopedCOMInitializer();
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ScopedCOMInitializer(const ScopedCOMInitializer&) = delete;
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ScopedCOMInitializer& operator=(const ScopedCOMInitializer&) = delete;
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bool Succeeded() { return SUCCEEDED(hr_); }
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private:
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void Initialize(COINIT init);
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HRESULT hr_;
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};
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} // namespace webrtc
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#endif // RTC_BASE_WIN_SCOPED_COM_INITIALIZER_H_
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