1 // Copyright 2018 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef PLATFORM_TEST_FAKE_CLOCK_H_ 6 #define PLATFORM_TEST_FAKE_CLOCK_H_ 7 8 #include <atomic> 9 #include <thread> 10 #include <vector> 11 12 #include "platform/api/time.h" 13 14 namespace openscreen { 15 16 class FakeTaskRunner; 17 18 class FakeClock { 19 public: 20 explicit FakeClock(Clock::time_point start_time); 21 ~FakeClock(); 22 23 // Moves the clock forward, simulating execution by running tasks in all 24 // FakeTaskRunners. The clock advances in one or more jumps, to ensure delayed 25 // tasks see the correct "now time" when they are executed. 26 void Advance(Clock::duration delta); 27 28 static Clock::time_point now() noexcept; 29 30 protected: 31 friend class FakeTaskRunner; 32 33 void SubscribeToTimeChanges(FakeTaskRunner* task_runner); 34 void UnsubscribeFromTimeChanges(FakeTaskRunner* task_runner); 35 36 private: 37 // Used for ensuring this FakeClock's lifecycle and mutations occur on the 38 // same thread. 39 const std::thread::id control_thread_id_; 40 41 std::vector<FakeTaskRunner*> task_runners_; 42 43 // This variable is atomic because some tests (e.g., TaskRunnerImplTest) will 44 // call now() on a different thread. 45 static std::atomic<Clock::time_point> now_; 46 }; 47 48 } // namespace openscreen 49 50 #endif // PLATFORM_TEST_FAKE_CLOCK_H_ 51