1 files changed, 29 insertions, 0 deletions
diff --git a/src/internal/syscall/unix/nonblocking_libc.go b/src/internal/syscall/unix/nonblocking_libc.go
new file mode 100644
index 0000000..1310dbf
--- /dev/null
+++ b/src/internal/syscall/unix/nonblocking_libc.go
@@ -0,0 +1,29 @@
+// 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.
+
+//go:build aix || darwin || (openbsd && !mips64) || solaris
+
+package unix
+
+import (
+	"syscall"
+	_ "unsafe" // for go:linkname
+)
+
+func IsNonblock(fd int) (nonblocking bool, err error) {
+	flag, e1 := fcntl(fd, syscall.F_GETFL, 0)
+	if e1 != nil {
+		return false, e1
+	}
+	return flag&syscall.O_NONBLOCK != 0, nil
+}
+
+func HasNonblockFlag(flag int) bool {
+	return flag&syscall.O_NONBLOCK != 0
+}
+
+// Implemented in the syscall package.
+//
+//go:linkname fcntl syscall.fcntl
+func fcntl(fd int, cmd int, arg int) (int, error)