mirror of https://github.com/golang/go.git
34 lines
1.2 KiB
Go
34 lines
1.2 KiB
Go
// Copyright 2024 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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//go:build !js
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package runtime
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// sleep and wakeup on one-time events.
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// before any calls to notesleep or notewakeup,
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// must call noteclear to initialize the Note.
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// then, exactly one thread can call notesleep
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// and exactly one thread can call notewakeup (once).
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// once notewakeup has been called, the notesleep
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// will return. future notesleep will return immediately.
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// subsequent noteclear must be called only after
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// previous notesleep has returned, e.g. it's disallowed
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// to call noteclear straight after notewakeup.
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//
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// notetsleep is like notesleep but wakes up after
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// a given number of nanoseconds even if the event
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// has not yet happened. if a goroutine uses notetsleep to
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// wake up early, it must wait to call noteclear until it
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// can be sure that no other goroutine is calling
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// notewakeup.
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//
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// notesleep/notetsleep are generally called on g0,
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// notetsleepg is similar to notetsleep but is called on user g.
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type note struct {
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// Futex-based impl treats it as uint32 key,
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// while sema-based impl as M* waitm.
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key uintptr
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}
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