1 files changed, 65 insertions, 0 deletions
diff --git a/src/runtime/semasleep_test.go b/src/runtime/semasleep_test.go
new file mode 100644
index 0000000..9b371b0
--- /dev/null
+++ b/src/runtime/semasleep_test.go
@@ -0,0 +1,65 @@
+// Copyright 2018 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 !plan9,!windows,!js
+
+package runtime_test
+
+import (
+	"os/exec"
+	"syscall"
+	"testing"
+	"time"
+)
+
+// Issue #27250. Spurious wakeups to pthread_cond_timedwait_relative_np
+// shouldn't cause semasleep to retry with the same timeout which would
+// cause indefinite spinning.
+func TestSpuriousWakeupsNeverHangSemasleep(t *testing.T) {
+	if *flagQuick {
+		t.Skip("-quick")
+	}
+
+	exe, err := buildTestProg(t, "testprog")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	start := time.Now()
+	cmd := exec.Command(exe, "After1")
+	if err := cmd.Start(); err != nil {
+		t.Fatalf("Failed to start command: %v", err)
+	}
+	doneCh := make(chan error, 1)
+	go func() {
+		doneCh <- cmd.Wait()
+	}()
+
+	// With the repro running, we can continuously send to it
+	// a non-terminal signal such as SIGIO, to spuriously
+	// wakeup pthread_cond_timedwait_relative_np.
+	unfixedTimer := time.NewTimer(2 * time.Second)
+	for {
+		select {
+		case <-time.After(200 * time.Millisecond):
+			// Send the pesky signal that toggles spinning
+			// indefinitely if #27520 is not fixed.
+			cmd.Process.Signal(syscall.SIGIO)
+
+		case <-unfixedTimer.C:
+			t.Error("Program failed to return on time and has to be killed, issue #27520 still exists")
+			cmd.Process.Signal(syscall.SIGKILL)
+			return
+
+		case err := <-doneCh:
+			if err != nil {
+				t.Fatalf("The program returned but unfortunately with an error: %v", err)
+			}
+			if time.Since(start) < 100*time.Millisecond {
+				t.Fatalf("The program stopped too quickly.")
+			}
+			return
+		}
+	}
+}