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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.
// +build darwin dragonfly freebsd linux netbsd openbsd solaris
package signal
import (
"flag"
"io/ioutil"
"os"
"os/exec"
"runtime"
"strconv"
"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 SIGHUP
c := make(chan os.Signal, 1)
Notify(c, syscall.SIGHUP)
defer Stop(c)
// Send this process a SIGHUP
t.Logf("sighup...")
syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
waitSig(t, c, syscall.SIGHUP)
// Ask for everything we can get.
c1 := make(chan os.Signal, 1)
Notify(c1)
// Send this process a SIGWINCH
t.Logf("sigwinch...")
syscall.Kill(syscall.Getpid(), syscall.SIGWINCH)
waitSig(t, c1, syscall.SIGWINCH)
// Send two more SIGHUPs, to make sure that
// they get delivered on c1 and that not reading
// from c does not block everything.
t.Logf("sighup...")
syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
waitSig(t, c1, syscall.SIGHUP)
t.Logf("sighup...")
syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
waitSig(t, c1, syscall.SIGHUP)
// The first SIGHUP should be waiting for us on c.
waitSig(t, c, syscall.SIGHUP)
}
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.SIGUSR1)
defer Stop(sig)
Loop:
for {
select {
case <-sig:
case <-done:
break Loop
}
}
finished <- true
}()
go func() {
Loop:
for {
select {
case <-done:
break Loop
default:
syscall.Kill(syscall.Getpid(), syscall.SIGUSR1)
runtime.Gosched()
}
}
finished <- true
}()
time.Sleep(dur)
close(done)
<-finished
<-finished
// When run with 'go test -cpu=1,2,4' SIGUSR1 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)
}
var sendUncaughtSighup = flag.Int("send_uncaught_sighup", 0, "send uncaught SIGHUP during TestStop")
// Test that Stop cancels the channel's registrations.
func TestStop(t *testing.T) {
sigs := []syscall.Signal{
syscall.SIGWINCH,
syscall.SIGHUP,
}
for _, sig := range sigs {
// Send the signal.
// If it's SIGWINCH, we should not see it.
// If it's SIGHUP, maybe we'll die. Let the flag tell us what to do.
if sig != syscall.SIGHUP || *sendUncaughtSighup == 1 {
syscall.Kill(syscall.Getpid(), sig)
}
time.Sleep(100 * time.Millisecond)
// Ask for signal
c := make(chan os.Signal, 1)
Notify(c, sig)
defer Stop(c)
// Send this process that signal
syscall.Kill(syscall.Getpid(), sig)
waitSig(t, c, 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 SIGWINCH, we should not see it.
// If it's SIGHUP, maybe we'll die. Let the flag tell us what to do.
if sig != syscall.SIGHUP || *sendUncaughtSighup == 2 {
syscall.Kill(syscall.Getpid(), sig)
}
select {
case s := <-c:
t.Fatalf("unexpected signal %v", s)
case <-time.After(100 * time.Millisecond):
// nothing to read - good
}
}
}
// Test that when run under nohup, an uncaught SIGHUP does not kill the program,
// but a
func TestNohup(t *testing.T) {
// Ugly: ask for SIGHUP so that child will not have no-hup set
// even if test is running under nohup environment.
// We have no intention of reading from c.
c := make(chan os.Signal, 1)
Notify(c, syscall.SIGHUP)
// When run without nohup, the test should crash on an uncaught SIGHUP.
// When run under nohup, the test should ignore uncaught SIGHUPs,
// because the runtime is not supposed to be listening for them.
// Either way, TestStop should still be able to catch them when it wants them
// and then when it stops wanting them, the original behavior should resume.
//
// send_uncaught_sighup=1 sends the SIGHUP before starting to listen for SIGHUPs.
// send_uncaught_sighup=2 sends the SIGHUP after no longer listening for SIGHUPs.
//
// Both should fail without nohup and succeed with nohup.
for i := 1; i <= 2; i++ {
out, err := exec.Command(os.Args[0], "-test.run=TestStop", "-send_uncaught_sighup="+strconv.Itoa(i)).CombinedOutput()
if err == nil {
t.Fatalf("ran test with -send_uncaught_sighup=%d and it succeeded: expected failure.\nOutput:\n%s", i, out)
}
}
Stop(c)
// Again, this time with nohup, assuming we can find it.
_, err := os.Stat("/usr/bin/nohup")
if err != nil {
t.Skip("cannot find nohup; skipping second half of test")
}
for i := 1; i <= 2; i++ {
os.Remove("nohup.out")
out, err := exec.Command("/usr/bin/nohup", os.Args[0], "-test.run=TestStop", "-send_uncaught_sighup="+strconv.Itoa(i)).CombinedOutput()
data, _ := ioutil.ReadFile("nohup.out")
os.Remove("nohup.out")
if err != nil {
t.Fatalf("ran test with -send_uncaught_sighup=%d under nohup and it failed: expected success.\nError: %v\nOutput:\n%s%s", i, err, out, data)
}
}
}
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