chromium/third_party/mediapipe/src/mediapipe/framework/deps/monotonic_clock.cc

// Copyright 2019 The MediaPipe Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "mediapipe/framework/deps/monotonic_clock.h"

#include "absl/base/macros.h"
#include "absl/base/thread_annotations.h"
#include "absl/log/absl_check.h"
#include "absl/log/absl_log.h"
#include "absl/synchronization/mutex.h"
#include "absl/time/time.h"

namespace mediapipe {

// This state, which contains the "guts" of MonotonicClockImpl, is separate
// from the class instance so that it can be shared to implement a
// SynchronizedMonotonicClock.  (The per-instance state of MonotonicClock is
// just for frills like the correction metrics and callback.)  It lives in this
// private namespace so that test code can use it without exposing it to the
// world.
struct MonotonicClock::State { … };

State;

class MonotonicClockImpl : public MonotonicClock { … };

// Factory methods.
MonotonicClock* MonotonicClock::CreateMonotonicClock(Clock* clock) { … }

namespace {
State* GlobalSyncState() { … }
}  // namespace

// The reason that SynchronizedMonotonicClock is not implemented as a singleton
// is so that different code bases can handle clock corrections their own way.
MonotonicClock* MonotonicClock::CreateSynchronizedMonotonicClock() { … }

// Test access methods.
void MonotonicClockAccess::SynchronizedMonotonicClockReset() { … }

State* MonotonicClockAccess::CreateMonotonicClockState(Clock* raw_clock) { … }

void MonotonicClockAccess::DeleteMonotonicClockState(State* state) { … }

MonotonicClock* MonotonicClockAccess::CreateMonotonicClock(State* state) { … }

}  // namespace mediapipe