1 // Copyright 2013 The Flutter 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 FLUTTER_SHELL_PLATFORM_FUCHSIA_VSYNC_RECORDER_H_ 6 #define FLUTTER_SHELL_PLATFORM_FUCHSIA_VSYNC_RECORDER_H_ 7 8 #include <optional> 9 10 #include "flutter/fml/time/time_delta.h" 11 #include "flutter/fml/time/time_point.h" 12 #include "lib/ui/scenic/cpp/session.h" 13 14 namespace flutter_runner { 15 16 struct VsyncInfo { 17 fml::TimePoint presentation_time; 18 fml::TimeDelta presentation_interval; 19 }; 20 21 class VsyncRecorder { 22 public: 23 static VsyncRecorder& GetInstance(); 24 25 // Retrieve the most recent |PresentationInfo| provided to us by scenic. 26 // This function is safe to call from any thread. 27 VsyncInfo GetCurrentVsyncInfo() const; 28 29 // Update the current Vsync info to |presentation_info|. This is expected 30 // to be called in |scenic::Sesssion::Present| callbacks with the 31 // presentation info provided by scenic. Only the most recent vsync 32 // information will be saved (in order to handle edge cases involving 33 // multiple scenic sessions in the same process). This function is safe to 34 // call from any thread. 35 void UpdateVsyncInfo(fuchsia::images::PresentationInfo presentation_info); 36 37 private: 38 VsyncRecorder() = default; 39 40 std::optional<fuchsia::images::PresentationInfo> last_presentation_info_; 41 42 // Disallow copy and assignment. 43 VsyncRecorder(const VsyncRecorder&) = delete; 44 VsyncRecorder& operator=(const VsyncRecorder&) = delete; 45 }; 46 47 } // namespace flutter_runner 48 49 #endif // FLUTTER_SHELL_PLATFORM_FUCHSIA_VSYNC_RECORDER_H_ 50