mirror of git://gcc.gnu.org/git/gcc.git
73 lines
1.8 KiB
Go
73 lines
1.8 KiB
Go
// Copyright 2012 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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// Package signal implements access to incoming signals.
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package signal
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// BUG(rsc): This package is not yet implemented on Plan 9 and Windows.
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import (
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"os"
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"sync"
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)
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var handlers struct {
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sync.Mutex
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list []handler
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}
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type handler struct {
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c chan<- os.Signal
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sig os.Signal
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all bool
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}
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// Notify causes package signal to relay incoming signals to c.
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// If no signals are listed, all incoming signals will be relayed to c.
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// Otherwise, just the listed signals will.
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//
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// Package signal will not block sending to c: the caller must ensure
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// that c has sufficient buffer space to keep up with the expected
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// signal rate. For a channel used for notification of just one signal value,
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// a buffer of size 1 is sufficient.
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//
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func Notify(c chan<- os.Signal, sig ...os.Signal) {
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if c == nil {
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panic("os/signal: Notify using nil channel")
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}
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handlers.Lock()
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defer handlers.Unlock()
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if len(sig) == 0 {
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enableSignal(nil)
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handlers.list = append(handlers.list, handler{c: c, all: true})
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} else {
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for _, s := range sig {
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// We use nil as a special wildcard value for enableSignal,
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// so filter it out of the list of arguments. This is safe because
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// we will never get an incoming nil signal, so discarding the
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// registration cannot affect the observed behavior.
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if s != nil {
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enableSignal(s)
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handlers.list = append(handlers.list, handler{c: c, sig: s})
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}
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}
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}
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}
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func process(sig os.Signal) {
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handlers.Lock()
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defer handlers.Unlock()
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for _, h := range handlers.list {
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if h.all || h.sig == sig {
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// send but do not block for it
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select {
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case h.c <- sig:
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default:
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}
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}
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}
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}
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