// Copyright 2018 The gVisor 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. package linux import ( "math" "time" ) const ( // ClockTick is the length of time represented by a single clock tick, as // used by times(2) and /proc/[pid]/stat. ClockTick = time.Second / CLOCKS_PER_SEC // CLOCKS_PER_SEC is the number of ClockTicks per second. // // Linux defines this to be 100 on most architectures, irrespective of // CONFIG_HZ. Userspace obtains the value through sysconf(_SC_CLK_TCK), // which uses the AT_CLKTCK entry in the auxiliary vector if one is // provided, and assumes 100 otherwise (glibc: // sysdeps/posix/sysconf.c:__sysconf() => // sysdeps/unix/sysv/linux/getclktck.c, elf/dl-support.c:_dl_aux_init()). // // Not to be confused with POSIX CLOCKS_PER_SEC, as used by clock(3); "XSI // requires that [POSIX] CLOCKS_PER_SEC equals 1000000 independent of the // actual resolution" - clock(3). CLOCKS_PER_SEC = 100 ) // CPU clock types for use with clock_gettime(2) et al. // // The 29 most significant bits of a 32 bit clock ID are either a PID or a FD. // // Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3. // // Bit 2 indicates whether a cpu clock refers to a thread or a process. const ( CPUCLOCK_PROF = 0 CPUCLOCK_VIRT = 1 CPUCLOCK_SCHED = 2 CPUCLOCK_MAX = 3 CLOCKFD = CPUCLOCK_MAX CPUCLOCK_CLOCK_MASK = 3 CPUCLOCK_PERTHREAD_MASK = 4 ) // Clock identifiers for use with clock_gettime(2), clock_getres(2), // clock_nanosleep(2). const ( CLOCK_REALTIME = 0 CLOCK_MONOTONIC = 1 CLOCK_PROCESS_CPUTIME_ID = 2 CLOCK_THREAD_CPUTIME_ID = 3 CLOCK_MONOTONIC_RAW = 4 CLOCK_REALTIME_COARSE = 5 CLOCK_MONOTONIC_COARSE = 6 CLOCK_BOOTTIME = 7 CLOCK_REALTIME_ALARM = 8 CLOCK_BOOTTIME_ALARM = 9 ) // Flags for clock_nanosleep(2). const ( TIMER_ABSTIME = 1 ) // Flags for timerfd syscalls (timerfd_create(2), timerfd_settime(2)). const ( // TFD_CLOEXEC is a timerfd_create flag. TFD_CLOEXEC = O_CLOEXEC // TFD_NONBLOCK is a timerfd_create flag. TFD_NONBLOCK = O_NONBLOCK // TFD_TIMER_ABSTIME is a timerfd_settime flag. TFD_TIMER_ABSTIME = 1 ) // The safe number of seconds you can represent by int64. const maxSecInDuration = math.MaxInt64 / int64(time.Second) // TimeT represents time_t in <time.h>. It represents time in seconds. type TimeT int64 // NsecToTimeT translates nanoseconds to TimeT (seconds). func NsecToTimeT(nsec int64) TimeT { return TimeT(nsec / 1e9) } // Timespec represents struct timespec in <time.h>. type Timespec struct { Sec int64 Nsec int64 } // Unix returns the second and nanosecond. func (ts Timespec) Unix() (sec int64, nsec int64) { return int64(ts.Sec), int64(ts.Nsec) } // ToTime returns the Go time.Time representation. func (ts Timespec) ToTime() time.Time { return time.Unix(ts.Sec, ts.Nsec) } // ToNsec returns the nanosecond representation. func (ts Timespec) ToNsec() int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) } // ToNsecCapped returns the safe nanosecond representation. func (ts Timespec) ToNsecCapped() int64 { if ts.Sec > maxSecInDuration { return math.MaxInt64 } return ts.ToNsec() } // ToDuration returns the safe nanosecond representation as time.Duration. func (ts Timespec) ToDuration() time.Duration { return time.Duration(ts.ToNsecCapped()) } // Valid returns whether the timespec contains valid values. func (ts Timespec) Valid() bool { return !(ts.Sec < 0 || ts.Nsec < 0 || ts.Nsec >= int64(time.Second)) } // NsecToTimespec translates nanoseconds to Timespec. func NsecToTimespec(nsec int64) (ts Timespec) { ts.Sec = nsec / 1e9 ts.Nsec = nsec % 1e9 return } // DurationToTimespec translates time.Duration to Timespec. func DurationToTimespec(dur time.Duration) Timespec { return NsecToTimespec(dur.Nanoseconds()) } // SizeOfTimeval is the size of a Timeval struct in bytes. const SizeOfTimeval = 16 // Timeval represents struct timeval in <time.h>. type Timeval struct { Sec int64 Usec int64 } // ToNsecCapped returns the safe nanosecond representation. func (tv Timeval) ToNsecCapped() int64 { if tv.Sec > maxSecInDuration { return math.MaxInt64 } return int64(tv.Sec)*1e9 + int64(tv.Usec)*1e3 } // ToDuration returns the safe nanosecond representation as a time.Duration. func (tv Timeval) ToDuration() time.Duration { return time.Duration(tv.ToNsecCapped()) } // ToTime returns the Go time.Time representation. func (tv Timeval) ToTime() time.Time { return time.Unix(tv.Sec, tv.Usec*1e3) } // NsecToTimeval translates nanosecond to Timeval. func NsecToTimeval(nsec int64) (tv Timeval) { nsec += 999 // round up to microsecond tv.Sec = nsec / 1e9 tv.Usec = nsec % 1e9 / 1e3 return } // DurationToTimeval translates time.Duration to Timeval. func DurationToTimeval(dur time.Duration) Timeval { return NsecToTimeval(dur.Nanoseconds()) } // Itimerspec represents struct itimerspec in <time.h>. type Itimerspec struct { Interval Timespec Value Timespec } // ItimerVal mimics the following struct in <sys/time.h> // struct itimerval { // struct timeval it_interval; /* next value */ // struct timeval it_value; /* current value */ // }; type ItimerVal struct { Interval Timeval Value Timeval } // ClockT represents type clock_t. type ClockT int64 // ClockTFromDuration converts time.Duration to clock_t. func ClockTFromDuration(d time.Duration) ClockT { return ClockT(d / ClockTick) } // Tms represents struct tms, used by times(2). type Tms struct { UTime ClockT STime ClockT CUTime ClockT CSTime ClockT } // TimerID represents type timer_t, which identifies a POSIX per-process // interval timer. type TimerID int32 // StatxTimestamp represents struct statx_timestamp. type StatxTimestamp struct { Sec int64 Nsec uint32 _ int32 } // ToNsec returns the nanosecond representation. func (sxts StatxTimestamp) ToNsec() int64 { return int64(sxts.Sec)*1e9 + int64(sxts.Nsec) } // ToNsecCapped returns the safe nanosecond representation. func (sxts StatxTimestamp) ToNsecCapped() int64 { if sxts.Sec > maxSecInDuration { return math.MaxInt64 } return sxts.ToNsec() } // NsecToStatxTimestamp translates nanoseconds to StatxTimestamp. func NsecToStatxTimestamp(nsec int64) (ts StatxTimestamp) { return StatxTimestamp{ Sec: nsec / 1e9, Nsec: uint32(nsec % 1e9), } } // Utime represents struct utimbuf used by utimes(2). type Utime struct { Actime int64 Modtime int64 }