1 files changed, 74 insertions, 0 deletions
diff --git a/src/runtime/nbpipe_test.go b/src/runtime/nbpipe_test.go
new file mode 100644
index 0000000..337b8e5
--- /dev/null
+++ b/src/runtime/nbpipe_test.go
@@ -0,0 +1,74 @@
+// Copyright 2019 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.
+
+//go:build unix
+
+package runtime_test
+
+import (
+	"runtime"
+	"syscall"
+	"testing"
+	"unsafe"
+)
+
+func TestNonblockingPipe(t *testing.T) {
+	// NonblockingPipe is the test name for nonblockingPipe.
+	r, w, errno := runtime.NonblockingPipe()
+	if errno != 0 {
+		t.Fatal(syscall.Errno(errno))
+	}
+	defer runtime.Close(w)
+
+	checkIsPipe(t, r, w)
+	checkNonblocking(t, r, "reader")
+	checkCloseonexec(t, r, "reader")
+	checkNonblocking(t, w, "writer")
+	checkCloseonexec(t, w, "writer")
+
+	// Test that fcntl returns an error as expected.
+	if runtime.Close(r) != 0 {
+		t.Fatalf("Close(%d) failed", r)
+	}
+	val, errno := runtime.Fcntl(r, syscall.F_GETFD, 0)
+	if val != -1 {
+		t.Errorf("Fcntl succeeded unexpectedly")
+	} else if syscall.Errno(errno) != syscall.EBADF {
+		t.Errorf("Fcntl failed with error %v, expected %v", syscall.Errno(errno), syscall.EBADF)
+	}
+}
+
+func checkIsPipe(t *testing.T, r, w int32) {
+	bw := byte(42)
+	if n := runtime.Write(uintptr(w), unsafe.Pointer(&bw), 1); n != 1 {
+		t.Fatalf("Write(w, &b, 1) == %d, expected 1", n)
+	}
+	var br byte
+	if n := runtime.Read(r, unsafe.Pointer(&br), 1); n != 1 {
+		t.Fatalf("Read(r, &b, 1) == %d, expected 1", n)
+	}
+	if br != bw {
+		t.Errorf("pipe read %d, expected %d", br, bw)
+	}
+}
+
+func checkNonblocking(t *testing.T, fd int32, name string) {
+	t.Helper()
+	flags, errno := runtime.Fcntl(fd, syscall.F_GETFL, 0)
+	if flags == -1 {
+		t.Errorf("fcntl(%s, F_GETFL) failed: %v", name, syscall.Errno(errno))
+	} else if flags&syscall.O_NONBLOCK == 0 {
+		t.Errorf("O_NONBLOCK not set in %s flags %#x", name, flags)
+	}
+}
+
+func checkCloseonexec(t *testing.T, fd int32, name string) {
+	t.Helper()
+	flags, errno := runtime.Fcntl(fd, syscall.F_GETFD, 0)
+	if flags == -1 {
+		t.Errorf("fcntl(%s, F_GETFD) failed: %v", name, syscall.Errno(errno))
+	} else if flags&syscall.FD_CLOEXEC == 0 {
+		t.Errorf("FD_CLOEXEC not set in %s flags %#x", name, flags)
+	}
+}