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author | Daniil Cherednik <dan.cherednik@gmail.com> | 2022-11-24 13:14:34 +0300 |
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committer | Daniil Cherednik <dan.cherednik@gmail.com> | 2022-11-24 14:46:00 +0300 |
commit | 87f7fceed34bcafb8aaff351dd493a35c916986f (patch) | |
tree | 26809ec8f550aba8eb019e59adc3d48e51913eb2 /contrib/go/_std_1.18/src/time/tick.go | |
parent | 11bc4015b8010ae201bf3eb33db7dba425aca35e (diff) | |
download | ydb-87f7fceed34bcafb8aaff351dd493a35c916986f.tar.gz |
Ydb stable 22-4-4322.4.43
x-stable-origin-commit: 8d49d46cc834835bf3e50870516acd7376a63bcf
Diffstat (limited to 'contrib/go/_std_1.18/src/time/tick.go')
-rw-r--r-- | contrib/go/_std_1.18/src/time/tick.go | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/contrib/go/_std_1.18/src/time/tick.go b/contrib/go/_std_1.18/src/time/tick.go new file mode 100644 index 0000000000..babf865aeb --- /dev/null +++ b/contrib/go/_std_1.18/src/time/tick.go @@ -0,0 +1,73 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package time + +import "errors" + +// A Ticker holds a channel that delivers ``ticks'' of a clock +// at intervals. +type Ticker struct { + C <-chan Time // The channel on which the ticks are delivered. + r runtimeTimer +} + +// NewTicker returns a new Ticker containing a channel that will send +// the current time on the channel after each tick. The period of the +// ticks is specified by the duration argument. The ticker will adjust +// the time interval or drop ticks to make up for slow receivers. +// The duration d must be greater than zero; if not, NewTicker will +// panic. Stop the ticker to release associated resources. +func NewTicker(d Duration) *Ticker { + if d <= 0 { + panic(errors.New("non-positive interval for NewTicker")) + } + // Give the channel a 1-element time buffer. + // If the client falls behind while reading, we drop ticks + // on the floor until the client catches up. + c := make(chan Time, 1) + t := &Ticker{ + C: c, + r: runtimeTimer{ + when: when(d), + period: int64(d), + f: sendTime, + arg: c, + }, + } + startTimer(&t.r) + return t +} + +// Stop turns off a ticker. After Stop, no more ticks will be sent. +// Stop does not close the channel, to prevent a concurrent goroutine +// reading from the channel from seeing an erroneous "tick". +func (t *Ticker) Stop() { + stopTimer(&t.r) +} + +// Reset stops a ticker and resets its period to the specified duration. +// The next tick will arrive after the new period elapses. The duration d +// must be greater than zero; if not, Reset will panic. +func (t *Ticker) Reset(d Duration) { + if d <= 0 { + panic("non-positive interval for Ticker.Reset") + } + if t.r.f == nil { + panic("time: Reset called on uninitialized Ticker") + } + modTimer(&t.r, when(d), int64(d), t.r.f, t.r.arg, t.r.seq) +} + +// Tick is a convenience wrapper for NewTicker providing access to the ticking +// channel only. While Tick is useful for clients that have no need to shut down +// the Ticker, be aware that without a way to shut it down the underlying +// Ticker cannot be recovered by the garbage collector; it "leaks". +// Unlike NewTicker, Tick will return nil if d <= 0. +func Tick(d Duration) <-chan Time { + if d <= 0 { + return nil + } + return NewTicker(d).C +} |