platform_system_core/include/utils/Timers.h
Michael Wright 65e93c3b6f Mark time conversion functions as constexpr
Change-Id: I753c6975a8e1d78978c31175b2e1868eb374c442
2015-04-20 15:06:01 +01:00

108 lines
3.5 KiB
C

/*
* Copyright (C) 2005 The Android Open Source Project
*
* 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.
*/
//
// Timer functions.
//
#ifndef _LIBS_UTILS_TIMERS_H
#define _LIBS_UTILS_TIMERS_H
#include <stdint.h>
#include <sys/types.h>
#include <sys/time.h>
#include <utils/Compat.h>
// ------------------------------------------------------------------
// C API
#ifdef __cplusplus
extern "C" {
#endif
typedef int64_t nsecs_t; // nano-seconds
static CONSTEXPR inline nsecs_t seconds_to_nanoseconds(nsecs_t secs)
{
return secs*1000000000;
}
static CONSTEXPR inline nsecs_t milliseconds_to_nanoseconds(nsecs_t secs)
{
return secs*1000000;
}
static CONSTEXPR inline nsecs_t microseconds_to_nanoseconds(nsecs_t secs)
{
return secs*1000;
}
static CONSTEXPR inline nsecs_t nanoseconds_to_seconds(nsecs_t secs)
{
return secs/1000000000;
}
static CONSTEXPR inline nsecs_t nanoseconds_to_milliseconds(nsecs_t secs)
{
return secs/1000000;
}
static CONSTEXPR inline nsecs_t nanoseconds_to_microseconds(nsecs_t secs)
{
return secs/1000;
}
static CONSTEXPR inline nsecs_t s2ns(nsecs_t v) {return seconds_to_nanoseconds(v);}
static CONSTEXPR inline nsecs_t ms2ns(nsecs_t v) {return milliseconds_to_nanoseconds(v);}
static CONSTEXPR inline nsecs_t us2ns(nsecs_t v) {return microseconds_to_nanoseconds(v);}
static CONSTEXPR inline nsecs_t ns2s(nsecs_t v) {return nanoseconds_to_seconds(v);}
static CONSTEXPR inline nsecs_t ns2ms(nsecs_t v) {return nanoseconds_to_milliseconds(v);}
static CONSTEXPR inline nsecs_t ns2us(nsecs_t v) {return nanoseconds_to_microseconds(v);}
static CONSTEXPR inline nsecs_t seconds(nsecs_t v) { return s2ns(v); }
static CONSTEXPR inline nsecs_t milliseconds(nsecs_t v) { return ms2ns(v); }
static CONSTEXPR inline nsecs_t microseconds(nsecs_t v) { return us2ns(v); }
enum {
SYSTEM_TIME_REALTIME = 0, // system-wide realtime clock
SYSTEM_TIME_MONOTONIC = 1, // monotonic time since unspecified starting point
SYSTEM_TIME_PROCESS = 2, // high-resolution per-process clock
SYSTEM_TIME_THREAD = 3, // high-resolution per-thread clock
SYSTEM_TIME_BOOTTIME = 4 // same as SYSTEM_TIME_MONOTONIC, but including CPU suspend time
};
// return the system-time according to the specified clock
#ifdef __cplusplus
nsecs_t systemTime(int clock = SYSTEM_TIME_MONOTONIC);
#else
nsecs_t systemTime(int clock);
#endif // def __cplusplus
/**
* Returns the number of milliseconds to wait between the reference time and the timeout time.
* If the timeout is in the past relative to the reference time, returns 0.
* If the timeout is more than INT_MAX milliseconds in the future relative to the reference time,
* such as when timeoutTime == LLONG_MAX, returns -1 to indicate an infinite timeout delay.
* Otherwise, returns the difference between the reference time and timeout time
* rounded up to the next millisecond.
*/
int toMillisecondTimeoutDelay(nsecs_t referenceTime, nsecs_t timeoutTime);
#ifdef __cplusplus
} // extern "C"
#endif
#endif // _LIBS_UTILS_TIMERS_H