libgo/go/os/signal/signal.go

   1 // Copyright 2009 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // Package signal implements operating system-independent signal handling.
   6 package signal
   7
   8 import (
   9         "runtime"
  10         "strconv"
  11 )
  12
  13 // A Signal can represent any operating system signal.
  14 type Signal interface {
  15         String() string
  16 }
  17
  18 type UnixSignal int32
  19
  20 func (sig UnixSignal) String() string {
  21         s := runtime.Signame(int32(sig))
  22         if len(s) > 0 {
  23                 return s
  24         }
  25         return "Signal " + strconv.Itoa(int(sig))
  26 }
  27
  28 // Incoming is the global signal channel.
  29 // All signals received by the program will be delivered to this channel.
  30 var Incoming <-chan Signal
  31
  32 func process(ch chan<- Signal) {
  33         for {
  34                 var mask uint32 = runtime.Sigrecv()
  35                 for sig := uint(0); sig < 32; sig++ {
  36                         if mask&(1<<sig) != 0 {
  37                                 ch <- UnixSignal(sig)
  38                         }
  39                 }
  40         }
  41 }
  42
  43 func init() {
  44         runtime.Siginit()
  45         ch := make(chan Signal) // Done here so Incoming can have type <-chan Signal
  46         Incoming = ch
  47         go process(ch)
  48 }