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// Copyright 2015 The Cobalt Authors. All Rights Reserved.
// 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
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
// Module Overview: Starboard Time module
// Provides access to system time and timers.
#include "starboard/export.h"
#include "starboard/types.h"
#ifdef __cplusplus
extern "C" {
// The number of microseconds since the epoch of January 1, 1601 UTC, or the
// number of microseconds between two times. Always microseconds, ALWAYS UTC.
typedef int64_t SbTime;
// A number of microseconds from some point. The main property of this time is
// that it increases monotonically. It should also be as high-resolution a timer
// as we can get on a platform. So, it is good for measuring the time between
// two calls without worrying about a system clock adjustment. It's not good
// for getting the wall clock time.
typedef int64_t SbTimeMonotonic;
// How many nanoseconds in one SbTime unit (microseconds).
#define kSbTimeNanosecondsPerMicrosecond ((SbTime)1000)
// One millisecond in SbTime units (microseconds).
#define kSbTimeMillisecond ((SbTime)1000)
// One second in SbTime units (microseconds).
#define kSbTimeSecond (kSbTimeMillisecond * 1000)
// One minute in SbTime units (microseconds).
#define kSbTimeMinute (kSbTimeSecond * 60)
// One hour in SbTime units (microseconds).
#define kSbTimeHour (kSbTimeMinute * 60)
// One day in SbTime units (microseconds).
#define kSbTimeDay (kSbTimeHour * 24)
// The maximum value of an SbTime.
#define kSbTimeMax (kSbInt64Max)
// A term that can be added to an SbTime to convert it into the number of
// microseconds since the POSIX epoch.
#define kSbTimeToPosixDelta (SB_INT64_C(-11644473600) * kSbTimeSecond)
// Converts |SbTime| into microseconds from the POSIX epoch.
// |time|: A time that is either measured in microseconds since the epoch of
// January 1, 1601, UTC, or that measures the number of microseconds
// between two times.
static SB_C_FORCE_INLINE int64_t SbTimeToPosix(SbTime time) {
return time + kSbTimeToPosixDelta;
// Converts microseconds from the POSIX epoch into an |SbTime|.
// |time|: A time that measures the number of microseconds since
// January 1, 1970, 00:00:00, UTC.
static SB_C_FORCE_INLINE SbTime SbTimeFromPosix(int64_t time) {
return time - kSbTimeToPosixDelta;
// Safely narrows a number from a more precise unit to a less precise one. This
// function rounds negative values toward negative infinity.
static SB_C_FORCE_INLINE int64_t SbTimeNarrow(int64_t time, int64_t divisor) {
return time >= 0 ? time / divisor : (time - divisor + 1) / divisor;
// Gets the current system time as an |SbTime|.
SB_EXPORT SbTime SbTimeGetNow();
// Gets a monotonically increasing time representing right now.
SB_EXPORT SbTimeMonotonic SbTimeGetMonotonicNow();
// Returns whether the current platform supports time thread now
SB_EXPORT bool SbTimeIsTimeThreadNowSupported();
// Gets a monotonically increasing time representing how long the current
// thread has been in the executing state (i.e. not pre-empted nor waiting
// on an event). This is not necessarily total time and is intended to allow
// measuring thread execution time between two timestamps. If this is not
// available then SbTimeGetMonotonicNow() should be used.
SB_EXPORT SbTimeMonotonic SbTimeGetMonotonicThreadNow();
#ifdef __cplusplus
} // extern "C"