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// 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 signal
import (
"os"
"runtime"
"syscall"
"testing"
"time"
)
func waitSig(t *testing.T, c <-chan os.Signal, sig os.Signal) {
select {
case s := <-c:
if s != sig {
t.Fatalf("signal was %v, want %v", s, sig)
}
case <-time.After(1 * time.Second):
t.Fatalf("timeout waiting for %v", sig)
}
}
// Test that basic signal handling works.
func TestSignal(t *testing.T) {
// Ask for hangup
c := make(chan os.Signal, 1)
Notify(c, syscall.Note("hangup"))
defer Stop(c)
// Send this process a hangup
t.Logf("hangup...")
postNote(syscall.Getpid(), "hangup")
waitSig(t, c, syscall.Note("hangup"))
// Ask for everything we can get.
c1 := make(chan os.Signal, 1)
Notify(c1)
// Send this process an alarm
t.Logf("alarm...")
postNote(syscall.Getpid(), "alarm")
waitSig(t, c1, syscall.Note("alarm"))
// Send two more hangups, to make sure that
// they get delivered on c1 and that not reading
// from c does not block everything.
t.Logf("hangup...")
postNote(syscall.Getpid(), "hangup")
waitSig(t, c1, syscall.Note("hangup"))
t.Logf("hangup...")
postNote(syscall.Getpid(), "hangup")
waitSig(t, c1, syscall.Note("hangup"))
// The first SIGHUP should be waiting for us on c.
waitSig(t, c, syscall.Note("hangup"))
}
func TestStress(t *testing.T) {
dur := 3 * time.Second
if testing.Short() {
dur = 100 * time.Millisecond
}
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(4))
done := make(chan bool)
finished := make(chan bool)
go func() {
sig := make(chan os.Signal, 1)
Notify(sig, syscall.Note("alarm"))
defer Stop(sig)
Loop:
for {
select {
case <-sig:
case <-done:
break Loop
}
}
finished <- true
}()
go func() {
Loop:
for {
select {
case <-done:
break Loop
default:
postNote(syscall.Getpid(), "alarm")
runtime.Gosched()
}
}
finished <- true
}()
time.Sleep(dur)
close(done)
<-finished
<-finished
// When run with 'go test -cpu=1,2,4' alarm from this test can slip
// into subsequent TestSignal() causing failure.
// Sleep for a while to reduce the possibility of the failure.
time.Sleep(10 * time.Millisecond)
}
// Test that Stop cancels the channel's registrations.
func TestStop(t *testing.T) {
if testing.Short() {
t.Skip("skipping in short mode")
}
sigs := []string{
"alarm",
"hangup",
}
for _, sig := range sigs {
// Send the signal.
// If it's alarm, we should not see it.
// If it's hangup, maybe we'll die. Let the flag tell us what to do.
if sig != "hangup" {
postNote(syscall.Getpid(), sig)
}
time.Sleep(100 * time.Millisecond)
// Ask for signal
c := make(chan os.Signal, 1)
Notify(c, syscall.Note(sig))
defer Stop(c)
// Send this process that signal
postNote(syscall.Getpid(), sig)
waitSig(t, c, syscall.Note(sig))
Stop(c)
select {
case s := <-c:
t.Fatalf("unexpected signal %v", s)
case <-time.After(100 * time.Millisecond):
// nothing to read - good
}
// Send the signal.
// If it's alarm, we should not see it.
// If it's hangup, maybe we'll die. Let the flag tell us what to do.
if sig != "hangup" {
postNote(syscall.Getpid(), sig)
}
select {
case s := <-c:
t.Fatalf("unexpected signal %v", s)
case <-time.After(100 * time.Millisecond):
// nothing to read - good
}
}
}
func itoa(val int) string {
if val < 0 {
return "-" + itoa(-val)
}
var buf [32]byte // big enough for int64
i := len(buf) - 1
for val >= 10 {
buf[i] = byte(val%10 + '0')
i--
val /= 10
}
buf[i] = byte(val + '0')
return string(buf[i:])
}
func postNote(pid int, note string) error {
f, err := os.OpenFile("/proc/"+itoa(pid)+"/note", os.O_WRONLY, 0)
if err != nil {
return err
}
defer f.Close()
_, err = f.Write([]byte(note))
return err
}
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