| // Copyright 2017 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 MEDIA_AUDIO_MAC_COREAUDIO_DISPATCH_OVERRIDE_H_ |
| #define MEDIA_AUDIO_MAC_COREAUDIO_DISPATCH_OVERRIDE_H_ |
| |
| namespace media { |
| // Initializes a CoreAudio hotfix, if supported (macOS >= 10.10). |
| // See: http://crbug.com/772410 |
| // The hotfix overrides calls to dispatch_get_global_queue() from two CoreAudio |
| // functions: HALC_IOContext_PauseIO and HALC_IOContext_ResumeIO. These dispatch |
| // blocks that should execute in-order, but the global queue does not guarantee |
| // this. When the calls execute out-of-order, we stop receiving callbacks for |
| // audio streams on one or more devices. |
| // |
| // To circumvent this problem, these two functions get handed an internal serial |
| // queue instead. For all other callers, the override will just defer to the |
| // normal dispatch_get_global_queue() implementation. |
| // |
| // Calls to this function must be serialized. Will do nothing if called when |
| // already initialized. |
| // |
| // Returns true if the hotfix is supported and initialization succeeded, or if |
| // it was already initialized; false otherwise. |
| bool InitializeCoreAudioDispatchOverride(); |
| } // namespace media |
| |
| #endif // MEDIA_AUDIO_MAC_COREAUDIO_DISPATCH_OVERRIDE_H_ |
