// Copyright 2017 The Abseil 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

//

//      https://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.

//

// -----------------------------------------------------------------------------

// File: clock.h

// -----------------------------------------------------------------------------

//

// This header file contains utility functions for working with the system-wide

// realtime clock. For descriptions of the main time abstractions used within

// this header file, consult the time.h header file.

#ifndef ABSL_TIME_CLOCK_H_

#define ABSL_TIME_CLOCK_H_

#include <cstdint>

#include "absl/base/config.h"

#include "absl/base/macros.h"

#include "absl/time/time.h"

namespace absl {

ABSL_NAMESPACE_BEGIN

// Now()

//

// Returns the current time, expressed as an `absl::Time` absolute time value.

absl::Time Now();

// GetCurrentTimeNanos()

//

// Returns the current time, expressed as a count of nanoseconds since the Unix

// Epoch (https://en.wikipedia.org/wiki/Unix_time). Prefer `absl::Now()` instead

// for all but the most performance-sensitive cases (i.e. when you are calling

// this function hundreds of thousands of times per second).

int64_t GetCurrentTimeNanos();

// SleepFor()

//

// Sleeps for the specified duration, expressed as an `absl::Duration`.

//

// Notes:

// * Signal interruptions will not reduce the sleep duration.

// * Returns immediately when passed a nonpositive duration.

void SleepFor(absl::Duration duration);

ABSL_NAMESPACE_END

}  // namespace absl

// -----------------------------------------------------------------------------

// Implementation Details

// -----------------------------------------------------------------------------

// In some build configurations we pass --detect-odr-violations to the

// gold linker.  This causes it to flag weak symbol overrides as ODR

// violations.  Because ODR only applies to C++ and not C,

// --detect-odr-violations ignores symbols not mangled with C++ names.

// By changing our extension points to be extern "C", we dodge this

// check.

extern "C" {

ABSL_DLL void ABSL_INTERNAL_C_SYMBOL(AbslInternalSleepFor)(

    absl::Duration duration);

}  // extern "C"

inline void absl::SleepFor(absl::Duration duration) {

  ABSL_INTERNAL_C_SYMBOL(AbslInternalSleepFor)(duration);

}

#endif  // ABSL_TIME_CLOCK_H_