1 /*
2  *  Copyright 2019 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 #ifndef RTC_BASE_SYNCHRONIZATION_YIELD_POLICY_H_
11 #define RTC_BASE_SYNCHRONIZATION_YIELD_POLICY_H_
12 
13 namespace rtc {
14 class YieldInterface {
15  public:
16   virtual ~YieldInterface() = default;
17   virtual void YieldExecution() = 0;
18 };
19 
20 // Sets the current thread-local yield policy while it's in scope and reverts
21 // to the previous policy when it leaves the scope.
22 class ScopedYieldPolicy final {
23  public:
24   explicit ScopedYieldPolicy(YieldInterface* policy);
25   ScopedYieldPolicy(const ScopedYieldPolicy&) = delete;
26   ScopedYieldPolicy& operator=(const ScopedYieldPolicy&) = delete;
27   ~ScopedYieldPolicy();
28   // Will yield as specified by the currently active thread-local yield policy
29   // (which by default is a no-op).
30   static void YieldExecution();
31 
32  private:
33   YieldInterface* const previous_;
34 };
35 
36 }  // namespace rtc
37 
38 #endif  // RTC_BASE_SYNCHRONIZATION_YIELD_POLICY_H_
39