32 lines
1011 B
Go
32 lines
1011 B
Go
// Copyright (c) 2016 Arista Networks, Inc.
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// Use of this source code is governed by the Apache License 2.0
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// that can be found in the COPYING file.
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// Package monotime provides a fast monotonic clock source.
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package monotime
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import (
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"time"
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_ "unsafe" // required to use //go:linkname
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)
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//go:noescape
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//go:linkname nanotime runtime.nanotime
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func nanotime() int64
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// Now returns the current time in nanoseconds from a monotonic clock.
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// The time returned is based on some arbitrary platform-specific point in the
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// past. The time returned is guaranteed to increase monotonically at a
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// constant rate, unlike time.Now() from the Go standard library, which may
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// slow down, speed up, jump forward or backward, due to NTP activity or leap
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// seconds.
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func Now() uint64 {
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return uint64(nanotime())
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}
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// Since returns the amount of time that has elapsed since t. t should be
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// the result of a call to Now() on the same machine.
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func Since(t uint64) time.Duration {
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return time.Duration(Now() - t)
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}
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