os: invoke processKiller synchronously in testKillProcess

Bryan C. Mills · Bryan C. Mills · commit 1deae0b59747 · 2021-01-15T18:29:43.000Z
Previously, testKillProcess needlessly invoked processKiller in a separate goroutine and failed to wait for that goroutine to complete, causing the calls to t.Fatalf in that goroutine to potentially occur after the test function had already returned. Fixes golang#43722 Change-Id: I5d03cb24af51bb73f0ff96419dac57ec39776967 Reviewed-on: https://go-review.googlesource.com/c/go/+/284153 Trust: Bryan C. Mills <bcmills@google.com> Trust: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com> TryBot-Result: Go Bot <gobot@golang.org>
diff --git a/src/os/os_test.go b/src/os/os_test.go
@@ -2298,21 +2298,23 @@ func TestLongPath(t *testing.T) {
 
 func testKillProcess(t *testing.T, processKiller func(p *Process)) {
 	testenv.MustHaveExec(t)
+	t.Parallel()
 
 	// Re-exec the test binary itself to emulate "sleep 1".
 	cmd := osexec.Command(Args[0], "-test.run", "TestSleep")
 	err := cmd.Start()
 	if err != nil {
 		t.Fatalf("Failed to start test process: %v", err)
 	}
-	go func() {
-		time.Sleep(100 * time.Millisecond)
-		processKiller(cmd.Process)
+
+	defer func() {
+		if err := cmd.Wait(); err == nil {
+			t.Errorf("Test process succeeded, but expected to fail")
+		}
 	}()
-	err = cmd.Wait()
-	if err == nil {
-		t.Errorf("Test process succeeded, but expected to fail")
-	}
+
+	time.Sleep(100 * time.Millisecond)
+	processKiller(cmd.Process)
 }
 
 // TestSleep emulates "sleep 1". It is a helper for testKillProcess, so we
