os/signal: add ability to ignore signals and restore initial signal handlers
There is currently no way to ignore signals using the os/signal package.
It is possible to catch a signal and do nothing but this is not the same
as ignoring it. The new function Ignore allows a set of signals to be
ignored. The new function Reset allows the initial handlers for a set of
signals to be restored.
Fixes #5572
Change-Id: I5c0f07956971e3a9ff9b9d9631e6e3a08c20df15
Reviewed-on: https://go-review.googlesource.com/3580
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/src/os/signal/signal_test.go b/src/os/signal/signal_test.go
index 22337a7..a71633c 100644
--- a/src/os/signal/signal_test.go
+++ b/src/os/signal/signal_test.go
@@ -109,6 +109,72 @@
time.Sleep(10 * time.Millisecond)
}
+func testCancel(t *testing.T, ignore bool) {
+ // Send SIGWINCH. By default this signal should be ignored.
+ syscall.Kill(syscall.Getpid(), syscall.SIGWINCH)
+ time.Sleep(100 * time.Millisecond)
+
+ // Ask to be notified on c1 when a SIGWINCH is received.
+ c1 := make(chan os.Signal, 1)
+ Notify(c1, syscall.SIGWINCH)
+ defer Stop(c1)
+
+ // Ask to be notified on c2 when a SIGHUP is received.
+ c2 := make(chan os.Signal, 1)
+ Notify(c2, syscall.SIGHUP)
+ defer Stop(c2)
+
+ // Send this process a SIGWINCH and wait for notification on c1.
+ syscall.Kill(syscall.Getpid(), syscall.SIGWINCH)
+ waitSig(t, c1, syscall.SIGWINCH)
+
+ // Send this process a SIGHUP and wait for notification on c2.
+ syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
+ waitSig(t, c2, syscall.SIGHUP)
+
+ // Ignore, or reset the signal handlers for, SIGWINCH and SIGHUP.
+ if ignore {
+ Ignore(syscall.SIGWINCH, syscall.SIGHUP)
+ } else {
+ Reset(syscall.SIGWINCH, syscall.SIGHUP)
+ }
+
+ // Send this process a SIGWINCH. It should be ignored.
+ syscall.Kill(syscall.Getpid(), syscall.SIGWINCH)
+
+ // If ignoring, Send this process a SIGHUP. It should be ignored.
+ if ignore {
+ syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
+ }
+
+ select {
+ case s := <-c1:
+ t.Fatalf("unexpected signal %v", s)
+ case <-time.After(100 * time.Millisecond):
+ // nothing to read - good
+ }
+
+ select {
+ case s := <-c2:
+ t.Fatalf("unexpected signal %v", s)
+ case <-time.After(100 * time.Millisecond):
+ // nothing to read - good
+ }
+
+ // Reset the signal handlers for all signals.
+ Reset()
+}
+
+// Test that Reset cancels registration for listed signals on all channels.
+func TestReset(t *testing.T) {
+ testCancel(t, false)
+}
+
+// Test that Ignore cancels registration for listed signals on all channels.
+func TestIgnore(t *testing.T) {
+ testCancel(t, true)
+}
+
var sendUncaughtSighup = flag.Int("send_uncaught_sighup", 0, "send uncaught SIGHUP during TestStop")
// Test that Stop cancels the channel's registrations.
