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.
27 // settleTime is an upper bound on how long we expect signals to take to be
28 // delivered. Lower values make the test faster, but also flakier — especially
29 // on heavily loaded systems.
31 // The current value is set based on flakes observed in the Go builders.
32 var settleTime = 100 * time.Millisecond
34 // fatalWaitingTime is an absurdly long time to wait for signals to be
35 // delivered but, using it, we (hopefully) eliminate test flakes on the
36 // build servers. See #46736 for discussion.
37 var fatalWaitingTime = 30 * time.Second
40 if testenv.Builder() == "solaris-amd64-oraclerel" {
41 // The solaris-amd64-oraclerel builder has been observed to time out in
42 // TestNohup even with a 250ms settle time.
44 // Use a much longer settle time on that builder to try to suss out whether
45 // the test is flaky due to builder slowness (which may mean we need a
46 // longer GO_TEST_TIMEOUT_SCALE) or due to a dropped signal (which may
47 // instead need a test-skip and upstream bug filed against the Solaris
50 // See https://golang.org/issue/33174.
51 settleTime = 5 * time.Second
52 } else if runtime.GOOS == "linux" && strings.HasPrefix(runtime.GOARCH, "ppc64") {
53 // Older linux kernels seem to have some hiccups delivering the signal
54 // in a timely manner on ppc64 and ppc64le. When running on a
55 // ppc64le/ubuntu 16.04/linux 4.4 host the time can vary quite
56 // substantially even on an idle system. 5 seconds is twice any value
57 // observed when running 10000 tests on such a system.
58 settleTime = 5 * time.Second
59 } else if s := os.Getenv("GO_TEST_TIMEOUT_SCALE"); s != "" {
60 if scale, err := strconv.Atoi(s); err == nil {
61 settleTime *= time.Duration(scale)
66 func waitSig(t *testing.T, c <-chan os.Signal, sig os.Signal) {
68 waitSig1(t, c, sig, false)
70 func waitSigAll(t *testing.T, c <-chan os.Signal, sig os.Signal) {
72 waitSig1(t, c, sig, true)
75 func waitSig1(t *testing.T, c <-chan os.Signal, sig os.Signal, all bool) {
78 // Sleep multiple times to give the kernel more tries to
79 // deliver the signal.
81 timer := time.NewTimer(settleTime / 10)
83 // If the caller notified for all signals on c, filter out SIGURG,
84 // which is used for runtime preemption and can come at unpredictable times.
85 // General user code should filter out all unexpected signals instead of just
86 // SIGURG, but since os/signal is tightly coupled to the runtime it seems
87 // appropriate to be stricter here.
88 for time.Since(start) < fatalWaitingTime {
94 if !all || s != syscall.SIGURG {
95 t.Fatalf("signal was %v, want %v", s, sig)
98 timer.Reset(settleTime / 10)
101 t.Fatalf("timeout after %v waiting for %v", fatalWaitingTime, sig)
104 // quiesce waits until we can be reasonably confident that all pending signals
105 // have been delivered by the OS.
107 // The kernel will deliver a signal as a thread returns
108 // from a syscall. If the only active thread is sleeping,
109 // and the system is busy, the kernel may not get around
110 // to waking up a thread to catch the signal.
111 // We try splitting up the sleep to give the kernel
112 // many chances to deliver the signal.
114 for time.Since(start) < settleTime {
115 time.Sleep(settleTime / 10)
119 // Test that basic signal handling works.
120 func TestSignal(t *testing.T) {
122 c := make(chan os.Signal, 1)
123 Notify(c, syscall.SIGHUP)
126 // Send this process a SIGHUP
128 syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
129 waitSig(t, c, syscall.SIGHUP)
131 // Ask for everything we can get. The buffer size has to be
132 // more than 1, since the runtime might send SIGURG signals.
133 // Using 10 is arbitrary.
134 c1 := make(chan os.Signal, 10)
136 // Stop relaying the SIGURG signals. See #49724
137 Reset(syscall.SIGURG)
140 // Send this process a SIGWINCH
141 t.Logf("sigwinch...")
142 syscall.Kill(syscall.Getpid(), syscall.SIGWINCH)
143 waitSigAll(t, c1, syscall.SIGWINCH)
145 // Send two more SIGHUPs, to make sure that
146 // they get delivered on c1 and that not reading
147 // from c does not block everything.
149 syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
150 waitSigAll(t, c1, syscall.SIGHUP)
152 syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
153 waitSigAll(t, c1, syscall.SIGHUP)
155 // The first SIGHUP should be waiting for us on c.
156 waitSig(t, c, syscall.SIGHUP)
159 func TestStress(t *testing.T) {
160 dur := 3 * time.Second
162 dur = 100 * time.Millisecond
164 defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(4))
166 sig := make(chan os.Signal, 1)
167 Notify(sig, syscall.SIGUSR1)
170 stop := time.After(dur)
174 // Allow enough time for all signals to be delivered before we stop
175 // listening for them.
178 // According to its documentation, “[w]hen Stop returns, it in
179 // guaranteed that c will receive no more signals.” So we can safely
180 // close sig here: if there is a send-after-close race here, that is a
181 // bug in Stop and we would like to detect it.
186 syscall.Kill(syscall.Getpid(), syscall.SIGUSR1)
193 // Receive signals until the sender closes sig.
197 func testCancel(t *testing.T, ignore bool) {
198 // Ask to be notified on c1 when a SIGWINCH is received.
199 c1 := make(chan os.Signal, 1)
200 Notify(c1, syscall.SIGWINCH)
203 // Ask to be notified on c2 when a SIGHUP is received.
204 c2 := make(chan os.Signal, 1)
205 Notify(c2, syscall.SIGHUP)
208 // Send this process a SIGWINCH and wait for notification on c1.
209 syscall.Kill(syscall.Getpid(), syscall.SIGWINCH)
210 waitSig(t, c1, syscall.SIGWINCH)
212 // Send this process a SIGHUP and wait for notification on c2.
213 syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
214 waitSig(t, c2, syscall.SIGHUP)
216 // Ignore, or reset the signal handlers for, SIGWINCH and SIGHUP.
217 // Either way, this should undo both calls to Notify above.
219 Ignore(syscall.SIGWINCH, syscall.SIGHUP)
220 // Don't bother deferring a call to Reset: it is documented to undo Notify,
221 // but its documentation says nothing about Ignore, and (as of the time of
222 // writing) it empirically does not undo an Ignore.
224 Reset(syscall.SIGWINCH, syscall.SIGHUP)
227 // Send this process a SIGWINCH. It should be ignored.
228 syscall.Kill(syscall.Getpid(), syscall.SIGWINCH)
230 // If ignoring, Send this process a SIGHUP. It should be ignored.
232 syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
239 t.Errorf("unexpected signal %v", s)
241 // nothing to read - good
246 t.Errorf("unexpected signal %v", s)
248 // nothing to read - good
251 // One or both of the signals may have been blocked for this process
252 // by the calling process.
253 // Discard any queued signals now to avoid interfering with other tests.
254 Notify(c1, syscall.SIGWINCH)
255 Notify(c2, syscall.SIGHUP)
259 // Test that Reset cancels registration for listed signals on all channels.
260 func TestReset(t *testing.T) {
264 // Test that Ignore cancels registration for listed signals on all channels.
265 func TestIgnore(t *testing.T) {
269 // Test that Ignored correctly detects changes to the ignored status of a signal.
270 func TestIgnored(t *testing.T) {
271 // Ask to be notified on SIGWINCH.
272 c := make(chan os.Signal, 1)
273 Notify(c, syscall.SIGWINCH)
275 // If we're being notified, then the signal should not be ignored.
276 if Ignored(syscall.SIGWINCH) {
277 t.Errorf("expected SIGWINCH to not be ignored.")
280 Ignore(syscall.SIGWINCH)
282 // We're no longer paying attention to this signal.
283 if !Ignored(syscall.SIGWINCH) {
284 t.Errorf("expected SIGWINCH to be ignored when explicitly ignoring it.")
290 var checkSighupIgnored = flag.Bool("check_sighup_ignored", false, "if true, TestDetectNohup will fail if SIGHUP is not ignored.")
292 // Test that Ignored(SIGHUP) correctly detects whether it is being run under nohup.
293 func TestDetectNohup(t *testing.T) {
294 if *checkSighupIgnored {
295 if !Ignored(syscall.SIGHUP) {
296 t.Fatal("SIGHUP is not ignored.")
298 t.Log("SIGHUP is ignored.")
302 // Ugly: ask for SIGHUP so that child will not have no-hup set
303 // even if test is running under nohup environment.
304 // We have no intention of reading from c.
305 c := make(chan os.Signal, 1)
306 Notify(c, syscall.SIGHUP)
307 if out, err := testenv.Command(t, os.Args[0], "-test.run=^TestDetectNohup$", "-check_sighup_ignored").CombinedOutput(); err == nil {
308 t.Errorf("ran test with -check_sighup_ignored and it succeeded: expected failure.\nOutput:\n%s", out)
311 // Again, this time with nohup, assuming we can find it.
312 _, err := os.Stat("/usr/bin/nohup")
314 t.Skip("cannot find nohup; skipping second half of test")
316 Ignore(syscall.SIGHUP)
317 os.Remove("nohup.out")
318 out, err := testenv.Command(t, "/usr/bin/nohup", os.Args[0], "-test.run=^TestDetectNohup$", "-check_sighup_ignored").CombinedOutput()
320 data, _ := os.ReadFile("nohup.out")
321 os.Remove("nohup.out")
323 t.Errorf("ran test with -check_sighup_ignored under nohup and it failed: expected success.\nError: %v\nOutput:\n%s%s", err, out, data)
329 sendUncaughtSighup = flag.Int("send_uncaught_sighup", 0, "send uncaught SIGHUP during TestStop")
330 dieFromSighup = flag.Bool("die_from_sighup", false, "wait to die from uncaught SIGHUP")
333 // Test that Stop cancels the channel's registrations.
334 func TestStop(t *testing.T) {
335 sigs := []syscall.Signal{
341 for _, sig := range sigs {
343 t.Run(fmt.Sprint(sig), func(t *testing.T) {
344 // When calling Notify with a specific signal,
345 // independent signals should not interfere with each other,
346 // and we end up needing to wait for signals to quiesce a lot.
347 // Test the three different signals concurrently.
350 // If the signal is not ignored, send the signal before registering a
351 // channel to verify the behavior of the default Go handler.
352 // If it's SIGWINCH or SIGUSR1 we should not see it.
353 // If it's SIGHUP, maybe we'll die. Let the flag tell us what to do.
354 mayHaveBlockedSignal := false
355 if !Ignored(sig) && (sig != syscall.SIGHUP || *sendUncaughtSighup == 1) {
356 syscall.Kill(syscall.Getpid(), sig)
359 // We don't know whether sig is blocked for this process; see
360 // https://golang.org/issue/38165. Assume that it could be.
361 mayHaveBlockedSignal = true
365 c := make(chan os.Signal, 1)
368 // Send this process the signal again.
369 syscall.Kill(syscall.Getpid(), sig)
372 if mayHaveBlockedSignal {
373 // We may have received a queued initial signal in addition to the one
374 // that we sent after Notify. If so, waitSig may have observed that
375 // initial signal instead of the second one, and we may need to wait for
376 // the second signal to clear. Do that now.
384 // Stop watching for the signal and send it again.
385 // If it's SIGHUP, maybe we'll die. Let the flag tell us what to do.
387 if sig != syscall.SIGHUP || *sendUncaughtSighup == 2 {
388 syscall.Kill(syscall.Getpid(), sig)
393 t.Errorf("unexpected signal %v", s)
395 // nothing to read - good
398 // If we're going to receive a signal, it has almost certainly been
399 // received by now. However, it may have been blocked for this process —
400 // we don't know. Explicitly unblock it and wait for it to clear now.
409 // Test that when run under nohup, an uncaught SIGHUP does not kill the program.
410 func TestNohup(t *testing.T) {
411 // Ugly: ask for SIGHUP so that child will not have no-hup set
412 // even if test is running under nohup environment.
413 // We have no intention of reading from c.
414 c := make(chan os.Signal, 1)
415 Notify(c, syscall.SIGHUP)
417 // When run without nohup, the test should crash on an uncaught SIGHUP.
418 // When run under nohup, the test should ignore uncaught SIGHUPs,
419 // because the runtime is not supposed to be listening for them.
420 // Either way, TestStop should still be able to catch them when it wants them
421 // and then when it stops wanting them, the original behavior should resume.
423 // send_uncaught_sighup=1 sends the SIGHUP before starting to listen for SIGHUPs.
424 // send_uncaught_sighup=2 sends the SIGHUP after no longer listening for SIGHUPs.
426 // Both should fail without nohup and succeed with nohup.
428 var subTimeout time.Duration
430 var wg sync.WaitGroup
432 if deadline, ok := t.Deadline(); ok {
433 subTimeout = time.Until(deadline)
434 subTimeout -= subTimeout / 10 // Leave 10% headroom for propagating output.
436 for i := 1; i <= 2; i++ {
438 go t.Run(fmt.Sprintf("uncaught-%d", i), func(t *testing.T) {
443 "-test.run=^TestStop$",
444 "-send_uncaught_sighup=" + strconv.Itoa(i),
448 args = append(args, fmt.Sprintf("-test.timeout=%v", subTimeout))
450 out, err := testenv.Command(t, os.Args[0], args...).CombinedOutput()
453 t.Errorf("ran test with -send_uncaught_sighup=%d and it succeeded: expected failure.\nOutput:\n%s", i, out)
455 t.Logf("test with -send_uncaught_sighup=%d failed as expected.\nError: %v\nOutput:\n%s", i, err, out)
463 // Skip the nohup test below when running in tmux on darwin, since nohup
464 // doesn't work correctly there. See issue #5135.
465 if runtime.GOOS == "darwin" && os.Getenv("TMUX") != "" {
466 t.Skip("Skipping nohup test due to running in tmux on darwin")
469 // Again, this time with nohup, assuming we can find it.
470 _, err := exec.LookPath("nohup")
472 t.Skip("cannot find nohup; skipping second half of test")
476 if deadline, ok := t.Deadline(); ok {
477 subTimeout = time.Until(deadline)
478 subTimeout -= subTimeout / 10 // Leave 10% headroom for propagating output.
480 for i := 1; i <= 2; i++ {
482 go t.Run(fmt.Sprintf("nohup-%d", i), func(t *testing.T) {
485 // POSIX specifies that nohup writes to a file named nohup.out if standard
486 // output is a terminal. However, for an exec.Cmd, standard output is
487 // not a terminal — so we don't need to read or remove that file (and,
488 // indeed, cannot even create it if the current user is unable to write to
489 // GOROOT/src, such as when GOROOT is installed and owned by root).
494 "-test.run=^TestStop$",
495 "-send_uncaught_sighup=" + strconv.Itoa(i),
498 args = append(args, fmt.Sprintf("-test.timeout=%v", subTimeout))
500 out, err := testenv.Command(t, "nohup", args...).CombinedOutput()
503 t.Errorf("ran test with -send_uncaught_sighup=%d under nohup and it failed: expected success.\nError: %v\nOutput:\n%s", i, err, out)
505 t.Logf("ran test with -send_uncaught_sighup=%d under nohup.\nOutput:\n%s", i, out)
512 // Test that SIGCONT works (issue 8953).
513 func TestSIGCONT(t *testing.T) {
514 c := make(chan os.Signal, 1)
515 Notify(c, syscall.SIGCONT)
517 syscall.Kill(syscall.Getpid(), syscall.SIGCONT)
518 waitSig(t, c, syscall.SIGCONT)
521 // Test race between stopping and receiving a signal (issue 14571).
522 func TestAtomicStop(t *testing.T) {
523 if os.Getenv("GO_TEST_ATOMIC_STOP") != "" {
524 atomicStopTestProgram(t)
525 t.Fatal("atomicStopTestProgram returned")
528 testenv.MustHaveExec(t)
530 // Call Notify for SIGINT before starting the child process.
531 // That ensures that SIGINT is not ignored for the child.
532 // This is necessary because if SIGINT is ignored when a
533 // Go program starts, then it remains ignored, and closing
534 // the last notification channel for SIGINT will switch it
535 // back to being ignored. In that case the assumption of
536 // atomicStopTestProgram, that it will either die from SIGINT
537 // or have it be reported, breaks down, as there is a third
538 // option: SIGINT might be ignored.
539 cs := make(chan os.Signal, 1)
540 Notify(cs, syscall.SIGINT)
544 for i := 0; i < execs; i++ {
546 if deadline, ok := t.Deadline(); ok {
547 timeout = time.Until(deadline).String()
549 cmd := testenv.Command(t, os.Args[0], "-test.run=^TestAtomicStop$", "-test.timeout="+timeout)
550 cmd.Env = append(os.Environ(), "GO_TEST_ATOMIC_STOP=1")
551 out, err := cmd.CombinedOutput()
554 t.Logf("iteration %d: output %s", i, out)
557 t.Logf("iteration %d: exit status %q: output: %s", i, err, out)
560 lost := bytes.Contains(out, []byte("lost signal"))
562 t.Errorf("iteration %d: lost signal", i)
565 // The program should either die due to SIGINT,
566 // or exit with success without printing "lost signal".
568 if len(out) > 0 && !lost {
569 t.Errorf("iteration %d: unexpected output", i)
572 if ee, ok := err.(*exec.ExitError); !ok {
573 t.Errorf("iteration %d: error (%v) has type %T; expected exec.ExitError", i, err, err)
574 } else if ws, ok := ee.Sys().(syscall.WaitStatus); !ok {
575 t.Errorf("iteration %d: error.Sys (%v) has type %T; expected syscall.WaitStatus", i, ee.Sys(), ee.Sys())
576 } else if !ws.Signaled() || ws.Signal() != syscall.SIGINT {
577 t.Errorf("iteration %d: got exit status %v; expected SIGINT", i, ee)
583 // atomicStopTestProgram is run in a subprocess by TestAtomicStop.
584 // It tries to trigger a signal delivery race. This function should
585 // either catch a signal or die from it.
586 func atomicStopTestProgram(t *testing.T) {
587 // This test won't work if SIGINT is ignored here.
588 if Ignored(syscall.SIGINT) {
589 fmt.Println("SIGINT is ignored")
595 timeout := 2 * time.Second
596 if deadline, ok := t.Deadline(); ok {
597 // Give each try an equal slice of the deadline, with one slice to spare for
599 timeout = time.Until(deadline) / (tries + 1)
602 pid := syscall.Getpid()
604 for i := 0; i < tries; i++ {
605 cs := make(chan os.Signal, 1)
606 Notify(cs, syscall.SIGINT)
608 var wg sync.WaitGroup
615 syscall.Kill(pid, syscall.SIGINT)
617 // At this point we should either die from SIGINT or
618 // get a notification on cs. If neither happens, we
619 // dropped the signal. It is given 2 seconds to
620 // deliver, as needed for gccgo on some loaded test systems.
624 case <-time.After(timeout):
626 fmt.Print("lost signal on tries:")
641 func TestTime(t *testing.T) {
642 // Test that signal works fine when we are in a call to get time,
643 // which on some platforms is using VDSO. See issue #34391.
644 dur := 3 * time.Second
646 dur = 100 * time.Millisecond
648 defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(4))
650 sig := make(chan os.Signal, 1)
651 Notify(sig, syscall.SIGUSR1)
653 stop := make(chan struct{})
658 // Allow enough time for all signals to be delivered before we stop
659 // listening for them.
662 // According to its documentation, “[w]hen Stop returns, it in
663 // guaranteed that c will receive no more signals.” So we can safely
664 // close sig here: if there is a send-after-close race, that is a bug in
665 // Stop and we would like to detect it.
670 syscall.Kill(syscall.Getpid(), syscall.SIGUSR1)
676 done := make(chan struct{})
679 // Receive signals until the sender closes sig.
685 for t1 := t0; t1.Sub(t0) < dur; t1 = time.Now() {
686 } // hammering on getting time
693 checkNotifyContext = flag.Bool("check_notify_ctx", false, "if true, TestNotifyContext will fail if SIGINT is not received.")
694 ctxNotifyTimes = flag.Int("ctx_notify_times", 1, "number of times a SIGINT signal should be received")
697 func TestNotifyContextNotifications(t *testing.T) {
698 if *checkNotifyContext {
699 ctx, _ := NotifyContext(context.Background(), syscall.SIGINT)
700 // We want to make sure not to be calling Stop() internally on NotifyContext() when processing a received signal.
701 // Being able to wait for a number of received system signals allows us to do so.
702 var wg sync.WaitGroup
705 for i := 0; i < n; i++ {
707 syscall.Kill(syscall.Getpid(), syscall.SIGINT)
713 fmt.Println("received SIGINT")
714 // Sleep to give time to simultaneous signals to reach the process.
715 // These signals must be ignored given stop() is not called on this code.
716 // We want to guarantee a SIGINT doesn't cause a premature termination of the program.
717 time.Sleep(settleTime)
722 testCases := []struct {
724 n int // number of times a SIGINT should be notified.
729 for _, tc := range testCases {
731 t.Run(tc.name, func(t *testing.T) {
734 var subTimeout time.Duration
735 if deadline, ok := t.Deadline(); ok {
736 timeout := time.Until(deadline)
737 if timeout < 2*settleTime {
738 t.Fatalf("starting test with less than %v remaining", 2*settleTime)
740 subTimeout = timeout - (timeout / 10) // Leave 10% headroom for cleaning up subprocess.
745 "-test.run=^TestNotifyContextNotifications$",
747 fmt.Sprintf("-ctx_notify_times=%d", tc.n),
750 args = append(args, fmt.Sprintf("-test.timeout=%v", subTimeout))
752 out, err := testenv.Command(t, os.Args[0], args...).CombinedOutput()
754 t.Errorf("ran test with -check_notify_ctx_notification and it failed with %v.\nOutput:\n%s", err, out)
756 if want := []byte("received SIGINT\n"); !bytes.Contains(out, want) {
757 t.Errorf("got %q, wanted %q", out, want)
763 func TestNotifyContextStop(t *testing.T) {
764 Ignore(syscall.SIGHUP)
765 if !Ignored(syscall.SIGHUP) {
766 t.Errorf("expected SIGHUP to be ignored when explicitly ignoring it.")
769 parent, cancelParent := context.WithCancel(context.Background())
771 c, stop := NotifyContext(parent, syscall.SIGHUP)
774 // If we're being notified, then the signal should not be ignored.
775 if Ignored(syscall.SIGHUP) {
776 t.Errorf("expected SIGHUP to not be ignored.")
779 if want, got := "signal.NotifyContext(context.Background.WithCancel, [hangup])", fmt.Sprint(c); want != got {
780 t.Errorf("c.String() = %q, wanted %q", got, want)
786 if got := c.Err(); got != context.Canceled {
787 t.Errorf("c.Err() = %q, want %q", got, context.Canceled)
789 case <-time.After(time.Second):
790 t.Errorf("timed out waiting for context to be done after calling stop")
794 func TestNotifyContextCancelParent(t *testing.T) {
795 parent, cancelParent := context.WithCancel(context.Background())
797 c, stop := NotifyContext(parent, syscall.SIGINT)
800 if want, got := "signal.NotifyContext(context.Background.WithCancel, [interrupt])", fmt.Sprint(c); want != got {
801 t.Errorf("c.String() = %q, want %q", got, want)
807 if got := c.Err(); got != context.Canceled {
808 t.Errorf("c.Err() = %q, want %q", got, context.Canceled)
810 case <-time.After(time.Second):
811 t.Errorf("timed out waiting for parent context to be canceled")
815 func TestNotifyContextPrematureCancelParent(t *testing.T) {
816 parent, cancelParent := context.WithCancel(context.Background())
819 cancelParent() // Prematurely cancel context before calling NotifyContext.
820 c, stop := NotifyContext(parent, syscall.SIGINT)
823 if want, got := "signal.NotifyContext(context.Background.WithCancel, [interrupt])", fmt.Sprint(c); want != got {
824 t.Errorf("c.String() = %q, want %q", got, want)
829 if got := c.Err(); got != context.Canceled {
830 t.Errorf("c.Err() = %q, want %q", got, context.Canceled)
832 case <-time.After(time.Second):
833 t.Errorf("timed out waiting for parent context to be canceled")
837 func TestNotifyContextSimultaneousStop(t *testing.T) {
838 c, stop := NotifyContext(context.Background(), syscall.SIGINT)
841 if want, got := "signal.NotifyContext(context.Background, [interrupt])", fmt.Sprint(c); want != got {
842 t.Errorf("c.String() = %q, want %q", got, want)
845 var wg sync.WaitGroup
848 for i := 0; i < n; i++ {
857 if got := c.Err(); got != context.Canceled {
858 t.Errorf("c.Err() = %q, want %q", got, context.Canceled)
860 case <-time.After(time.Second):
861 t.Errorf("expected context to be canceled")
865 func TestNotifyContextStringer(t *testing.T) {
866 parent, cancelParent := context.WithCancel(context.Background())
868 c, stop := NotifyContext(parent, syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM)
871 want := `signal.NotifyContext(context.Background.WithCancel, [hangup interrupt terminated])`
872 if got := fmt.Sprint(c); got != want {
873 t.Errorf("c.String() = %q, want %q", got, want)
877 // #44193 test signal handling while stopping and starting the world.
878 func TestSignalTrace(t *testing.T) {
879 done := make(chan struct{})
880 quit := make(chan struct{})
881 c := make(chan os.Signal, 1)
882 Notify(c, syscall.SIGHUP)
884 // Source and sink for signals busy loop unsynchronized with
885 // trace starts and stops. We are ultimately validating that
886 // signals and runtime.(stop|start)TheWorldGC are compatible.
890 pid := syscall.Getpid()
896 syscall.Kill(pid, syscall.SIGHUP)
898 waitSig(t, c, syscall.SIGHUP)
902 for i := 0; i < 100; i++ {
903 buf := new(bytes.Buffer)
904 if err := trace.Start(buf); err != nil {
905 t.Fatalf("[%d] failed to start tracing: %v", i, err)
907 time.After(1 * time.Microsecond)
911 t.Fatalf("[%d] trace is empty", i)