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63 lines
2.1 KiB
C++
63 lines
2.1 KiB
C++
// Copyright 2013 The Flutter Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "flutter/shell/common/vsync_waiter_fallback.h"
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#include <memory>
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#include "flutter/fml/logging.h"
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#include "flutter/fml/message_loop.h"
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#include "flutter/fml/trace_event.h"
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namespace flutter {
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namespace {
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static fml::TimePoint SnapToNextTick(fml::TimePoint value,
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fml::TimePoint tick_phase,
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fml::TimeDelta tick_interval) {
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fml::TimeDelta offset = (tick_phase - value) % tick_interval;
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if (offset != fml::TimeDelta::Zero()) {
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offset = offset + tick_interval;
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}
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return value + offset;
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}
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} // namespace
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VsyncWaiterFallback::VsyncWaiterFallback(const TaskRunners& task_runners,
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bool for_testing)
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: VsyncWaiter(task_runners),
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phase_(fml::TimePoint::Now()),
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for_testing_(for_testing) {}
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VsyncWaiterFallback::~VsyncWaiterFallback() = default;
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// |VsyncWaiter|
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void VsyncWaiterFallback::AwaitVSync() {
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constexpr fml::TimeDelta kSingleFrameInterval =
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fml::TimeDelta::FromSecondsF(1.0 / 60.0);
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auto frame_start_time =
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SnapToNextTick(fml::TimePoint::Now(), phase_, kSingleFrameInterval);
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auto frame_target_time = frame_start_time + kSingleFrameInterval;
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TRACE_EVENT2_INT("flutter", "PlatformVsync", "frame_start_time",
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frame_start_time.ToEpochDelta().ToMicroseconds(),
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"frame_target_time",
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frame_target_time.ToEpochDelta().ToMicroseconds());
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std::weak_ptr<VsyncWaiterFallback> weak_this =
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std::static_pointer_cast<VsyncWaiterFallback>(shared_from_this());
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task_runners_.GetUITaskRunner()->PostTaskForTime(
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[frame_start_time, frame_target_time, weak_this]() {
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if (auto vsync_waiter = weak_this.lock()) {
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vsync_waiter->FireCallback(frame_start_time, frame_target_time,
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!vsync_waiter->for_testing_);
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}
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},
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frame_start_time);
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}
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} // namespace flutter
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