1 files changed, 208 insertions, 0 deletions
diff --git a/src/os/signal/signal_test.go b/src/os/signal/signal_test.go
new file mode 100644
index 000000000..22337a72d
--- /dev/null
+++ b/src/os/signal/signal_test.go
@@ -0,0 +1,208 @@
+// 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)
+		}
+	}
+}