runtime: define nonblockingPipe

This requires defining pipe, pipe2, and setNonblock for various platforms.

The new function is currently only used on AIX. It will be used by
later CLs in this series.

Updates #27707

Change-Id: Id2f987b66b4c66a3ef40c22484ff1d14f58e9b31
Reviewed-on: https://go-review.googlesource.com/c/go/+/171822
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/runtime/defs1_linux.go

@@ -21,6 +21,7 @@ import "C"
 
 const (
 	O_RDONLY    = C.O_RDONLY
+	O_NONBLOCK  = C.O_NONBLOCK
 	O_CLOEXEC   = C.O_CLOEXEC
 	SA_RESTORER = C.SA_RESTORER
 )

src/runtime/defs1_netbsd_386.go

@@ -6,6 +6,10 @@ package runtime
 const (
 	_EINTR  = 0x4
 	_EFAULT = 0xe
+	_ENOSYS = 0x4e
+
+	_O_NONBLOCK = 0x4
+	_O_CLOEXEC  = 0x400000
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1

src/runtime/defs1_netbsd_amd64.go

@@ -6,6 +6,10 @@ package runtime
 const (
 	_EINTR  = 0x4
 	_EFAULT = 0xe
+	_ENOSYS = 0x4e
+
+	_O_NONBLOCK = 0x4
+	_O_CLOEXEC  = 0x400000
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1

src/runtime/defs1_netbsd_arm.go

@@ -6,6 +6,10 @@ package runtime
 const (
 	_EINTR  = 0x4
 	_EFAULT = 0xe
+	_ENOSYS = 0x4e
+
+	_O_NONBLOCK = 0x4
+	_O_CLOEXEC  = 0x400000
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1

src/runtime/defs1_netbsd_arm64.go

@@ -6,6 +6,10 @@ package runtime
 const (
 	_EINTR  = 0x4
 	_EFAULT = 0xe
+	_ENOSYS = 0x4e
+
+	_O_NONBLOCK = 0x4
+	_O_CLOEXEC  = 0x400000
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1

src/runtime/defs_aix.go

@@ -124,6 +124,7 @@ const (
 	_ITIMER_PROF    = C.ITIMER_PROF
 
 	_O_RDONLY   = C.O_RDONLY
+	_O_NONBLOCK = C.O_NONBLOCK
 
 	_SS_DISABLE  = C.SS_DISABLE
 	_SI_USER     = C.SI_USER

src/runtime/defs_aix_ppc64.go

@@ -81,6 +81,7 @@ const (
 	_ITIMER_PROF    = 0x2
 
 	_O_RDONLY   = 0x0
+	_O_NONBLOCK = 0x4
 
 	_SS_DISABLE  = 0x2
 	_SI_USER     = 0x0

src/runtime/defs_freebsd.go

@@ -47,6 +47,10 @@ const (
 const (
 	EINTR  = C.EINTR
 	EFAULT = C.EFAULT
+	ENOSYS = C.ENOSYS
+
+	O_NONBLOCK = C.O_NONBLOCK
+	O_CLOEXEC  = C.O_CLOEXEC
 
 	PROT_NONE  = C.PROT_NONE
 	PROT_READ  = C.PROT_READ

src/runtime/defs_freebsd_386.go

@@ -15,6 +15,10 @@ const (
 const (
 	_EINTR  = 0x4
 	_EFAULT = 0xe
+	_ENOSYS = 0x4e
+
+	_O_NONBLOCK = 0x4
+	_O_CLOEXEC  = 0x100000
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1

src/runtime/defs_freebsd_amd64.go

@@ -15,6 +15,10 @@ const (
 const (
 	_EINTR  = 0x4
 	_EFAULT = 0xe
+	_ENOSYS = 0x4e
+
+	_O_NONBLOCK = 0x4
+	_O_CLOEXEC  = 0x100000
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1

src/runtime/defs_freebsd_arm.go

@@ -15,6 +15,10 @@ const (
 const (
 	_EINTR  = 0x4
 	_EFAULT = 0xe
+	_ENOSYS = 0x4e
+
+	_O_NONBLOCK = 0x4
+	_O_CLOEXEC  = 0x100000
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1

src/runtime/defs_linux.go

@@ -37,6 +37,7 @@ const (
 	EINTR  = C.EINTR
 	EAGAIN = C.EAGAIN
 	ENOMEM = C.ENOMEM
+	ENOSYS = C.ENOSYS
 
 	PROT_NONE  = C.PROT_NONE
 	PROT_READ  = C.PROT_READ

src/runtime/defs_linux_386.go

@@ -7,6 +7,7 @@ const (
 	_EINTR  = 0x4
 	_EAGAIN = 0xb
 	_ENOMEM = 0xc
+	_ENOSYS = 0x26
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1
@@ -79,6 +80,7 @@ const (
 	_ITIMER_PROF    = 0x2
 
 	_O_RDONLY   = 0x0
+	_O_NONBLOCK = 0x800
 	_O_CLOEXEC  = 0x80000
 
 	_EPOLLIN       = 0x1

src/runtime/defs_linux_amd64.go

@@ -7,6 +7,7 @@ const (
 	_EINTR  = 0x4
 	_EAGAIN = 0xb
 	_ENOMEM = 0xc
+	_ENOSYS = 0x26
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1
@@ -144,6 +145,7 @@ type epollevent struct {
 
 const (
 	_O_RDONLY   = 0x0
+	_O_NONBLOCK = 0x800
 	_O_CLOEXEC  = 0x80000
 )
 

src/runtime/defs_linux_arm.go

@@ -5,6 +5,7 @@ const (
 	_EINTR  = 0x4
 	_ENOMEM = 0xc
 	_EAGAIN = 0xb
+	_ENOSYS = 0x26
 
 	_PROT_NONE  = 0
 	_PROT_READ  = 0x1
@@ -71,6 +72,7 @@ const (
 	_ITIMER_PROF    = 0x2
 	_ITIMER_VIRTUAL = 0x1
 	_O_RDONLY       = 0
+	_O_NONBLOCK     = 0x800
 	_O_CLOEXEC      = 0x80000
 
 	_EPOLLIN       = 0x1

src/runtime/defs_linux_arm64.go

@@ -7,6 +7,7 @@ const (
 	_EINTR  = 0x4
 	_EAGAIN = 0xb
 	_ENOMEM = 0xc
+	_ENOSYS = 0x26
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1
@@ -145,6 +146,7 @@ type epollevent struct {
 
 const (
 	_O_RDONLY   = 0x0
+	_O_NONBLOCK = 0x800
 	_O_CLOEXEC  = 0x80000
 )
 

src/runtime/defs_linux_mips64x.go

@@ -7,6 +7,7 @@ const (
 	_EINTR  = 0x4
 	_EAGAIN = 0xb
 	_ENOMEM = 0xc
+	_ENOSYS = 0x59
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1
@@ -145,6 +146,7 @@ type epollevent struct {
 
 const (
 	_O_RDONLY    = 0x0
+	_O_NONBLOCK  = 0x80
 	_O_CLOEXEC   = 0x80000
 	_SA_RESTORER = 0
 )

src/runtime/defs_linux_mipsx.go

@@ -11,6 +11,7 @@ const (
 	_EINTR  = 0x4
 	_EAGAIN = 0xb
 	_ENOMEM = 0xc
+	_ENOSYS = 0x59
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1
@@ -143,6 +144,7 @@ type epollevent struct {
 
 const (
 	_O_RDONLY    = 0x0
+	_O_NONBLOCK  = 0x80
 	_O_CLOEXEC   = 0x80000
 	_SA_RESTORER = 0
 )

src/runtime/defs_linux_ppc64.go

@@ -7,6 +7,7 @@ const (
 	_EINTR  = 0x4
 	_EAGAIN = 0xb
 	_ENOMEM = 0xc
+	_ENOSYS = 0x26
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1
@@ -145,6 +146,7 @@ type epollevent struct {
 
 const (
 	_O_RDONLY    = 0x0
+	_O_NONBLOCK  = 0x800
 	_O_CLOEXEC   = 0x80000
 	_SA_RESTORER = 0
 )

src/runtime/defs_linux_ppc64le.go

@@ -7,6 +7,7 @@ const (
 	_EINTR  = 0x4
 	_EAGAIN = 0xb
 	_ENOMEM = 0xc
+	_ENOSYS = 0x26
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1
@@ -145,6 +146,7 @@ type epollevent struct {
 
 const (
 	_O_RDONLY    = 0x0
+	_O_NONBLOCK  = 0x800
 	_O_CLOEXEC   = 0x80000
 	_SA_RESTORER = 0
 )

src/runtime/defs_linux_s390x.go

@@ -8,6 +8,7 @@ const (
 	_EINTR  = 0x4
 	_EAGAIN = 0xb
 	_ENOMEM = 0xc
+	_ENOSYS = 0x26
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1
@@ -138,6 +139,7 @@ type epollevent struct {
 
 const (
 	_O_RDONLY    = 0x0
+	_O_NONBLOCK  = 0x800
 	_O_CLOEXEC   = 0x80000
 	_SA_RESTORER = 0
 )

src/runtime/defs_netbsd.go

@@ -32,6 +32,10 @@ import "C"
 const (
 	EINTR  = C.EINTR
 	EFAULT = C.EFAULT
+	ENOSYS = C.ENOSYS
+
+	O_NONBLOCK = C.O_NONBLOCK
+	O_CLOEXEC  = C.O_CLOEXEC
 
 	PROT_NONE  = C.PROT_NONE
 	PROT_READ  = C.PROT_READ

src/runtime/defs_openbsd.go

@@ -28,6 +28,10 @@ import "C"
 const (
 	EINTR  = C.EINTR
 	EFAULT = C.EFAULT
+	ENOSYS = C.ENOSYS
+
+	O_NONBLOCK = C.O_NONBLOCK
+	O_CLOEXEC  = C.O_CLOEXEC
 
 	PROT_NONE  = C.PROT_NONE
 	PROT_READ  = C.PROT_READ

src/runtime/defs_openbsd_386.go

@@ -8,6 +8,10 @@ import "unsafe"
 const (
 	_EINTR  = 0x4
 	_EFAULT = 0xe
+	_ENOSYS = 0x4e
+
+	_O_NONBLOCK = 0x4
+	_O_CLOEXEC  = 0x10000
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1

src/runtime/defs_openbsd_amd64.go

@@ -8,6 +8,10 @@ import "unsafe"
 const (
 	_EINTR  = 0x4
 	_EFAULT = 0xe
+	_ENOSYS = 0x4e
+
+	_O_NONBLOCK = 0x4
+	_O_CLOEXEC  = 0x10000
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1

src/runtime/defs_openbsd_arm.go

@@ -8,6 +8,10 @@ import "unsafe"
 const (
 	_EINTR  = 0x4
 	_EFAULT = 0xe
+	_ENOSYS = 0x4e
+
+	_O_NONBLOCK = 0x4
+	_O_CLOEXEC  = 0x10000
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1

src/runtime/defs_openbsd_arm64.go

@@ -5,6 +5,10 @@ import "unsafe"
 const (
 	_EINTR  = 0x4
 	_EFAULT = 0xe
+	_ENOSYS = 0x4e
+
+	_O_NONBLOCK = 0x4
+	_O_CLOEXEC  = 0x10000
 
 	_PROT_NONE  = 0x0
 	_PROT_READ  = 0x1

src/runtime/export_nbpipe_test.go

@@ -0,0 +1,12 @@
+// 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.
+
+// +build aix darwin dragonfly freebsd linux netbsd openbsd
+
+package runtime
+
+var NonblockingPipe = nonblockingPipe
+var Pipe = pipe
+var SetNonblock = setNonblock
+var Closeonexec = closeonexec

src/runtime/nbpipe_pipe.go

@@ -0,0 +1,19 @@
+// 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.
+
+// +build aix darwin dragonfly
+
+package runtime
+
+func nonblockingPipe() (r, w int32, errno int32) {
+	r, w, errno = pipe()
+	if errno != 0 {
+		return -1, -1, errno
+	}
+	closeonexec(r)
+	setNonblock(r)
+	closeonexec(w)
+	setNonblock(w)
+	return r, w, errno
+}

src/runtime/nbpipe_pipe2.go

@@ -0,0 +1,25 @@
+// 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.
+
+// +build freebsd linux netbsd openbsd
+
+package runtime
+
+func pipe() (r, w int32, errno int32)
+func pipe2(flags int32) (r, w int32, errno int32)
+
+func nonblockingPipe() (r, w int32, errno int32) {
+	r, w, errno = pipe2(_O_NONBLOCK | _O_CLOEXEC)
+	if errno == -_ENOSYS {
+		r, w, errno = pipe()
+		if errno != 0 {
+			return -1, -1, errno
+		}
+		closeonexec(r)
+		setNonblock(r)
+		closeonexec(w)
+		setNonblock(w)
+	}
+	return r, w, errno
+}

src/runtime/nbpipe_test.go

@@ -0,0 +1,93 @@
+// 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.
+
+// +build aix darwin dragonfly freebsd linux netbsd openbsd
+
+package runtime_test
+
+import (
+	"runtime"
+	"syscall"
+	"testing"
+	"unsafe"
+)
+
+func TestNonblockingPipe(t *testing.T) {
+	t.Parallel()
+
+	// NonblockingPipe is the test name for nonblockingPipe.
+	r, w, errno := runtime.NonblockingPipe()
+	if errno != 0 {
+		t.Fatal(syscall.Errno(errno))
+	}
+	defer func() {
+		runtime.Close(r)
+		runtime.Close(w)
+	}()
+
+	checkIsPipe(t, r, w)
+	checkNonblocking(t, r, "reader")
+	checkCloseonexec(t, r, "reader")
+	checkNonblocking(t, w, "writer")
+	checkCloseonexec(t, w, "writer")
+}
+
+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 := syscall.Syscall(syscall.SYS_FCNTL, uintptr(fd), syscall.F_GETFL, 0)
+	if errno != 0 {
+		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 := syscall.Syscall(syscall.SYS_FCNTL, uintptr(fd), syscall.F_GETFD, 0)
+	if errno != 0 {
+		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)
+	}
+}
+
+func TestSetNonblock(t *testing.T) {
+	t.Parallel()
+
+	r, w, errno := runtime.Pipe()
+	if errno != 0 {
+		t.Fatal(syscall.Errno(errno))
+	}
+	defer func() {
+		runtime.Close(r)
+		runtime.Close(w)
+	}()
+
+	checkIsPipe(t, r, w)
+
+	runtime.SetNonblock(r)
+	runtime.SetNonblock(w)
+	checkNonblocking(t, r, "reader")
+	checkNonblocking(t, w, "writer")
+
+	runtime.Closeonexec(r)
+	runtime.Closeonexec(w)
+	checkCloseonexec(t, r, "reader")
+	checkCloseonexec(t, w, "writer")
+}

src/runtime/netpoll_aix.go

@@ -21,12 +21,6 @@ func poll(pfds *pollfd, npfds uintptr, timeout uintptr) (int32, int32) {
 	return int32(r), int32(err)
 }
 
-//go:nosplit
-func fcntl(fd, cmd int32, arg uintptr) int32 {
-	r, _ := syscall3(&libc_fcntl, uintptr(fd), uintptr(cmd), arg)
-	return int32(r)
-}
-
 // pollfd represents the poll structure for AIX operating system.
 type pollfd struct {
 	fd      int32
@@ -38,7 +32,6 @@ const _POLLIN = 0x0001
 const _POLLOUT = 0x0002
 const _POLLHUP = 0x2000
 const _POLLERR = 0x4000
-const _O_NONBLOCK = 0x4
 
 var (
 	pfds           []pollfd
@@ -51,22 +44,13 @@ var (
 )
 
 func netpollinit() {
-	var p [2]int32
-
 	// Create the pipe we use to wakeup poll.
-	if err := pipe(&p[0]); err < 0 {
+	r, w, errno := nonblockingPipe()
+	if errno != 0 {
 		throw("netpollinit: failed to create pipe")
 	}
-	rdwake = p[0]
-	wrwake = p[1]
-
-	fl := uintptr(fcntl(rdwake, _F_GETFL, 0))
-	fcntl(rdwake, _F_SETFL, fl|_O_NONBLOCK)
-	fcntl(rdwake, _F_SETFD, _FD_CLOEXEC)
-
-	fl = uintptr(fcntl(wrwake, _F_GETFL, 0))
-	fcntl(wrwake, _F_SETFL, fl|_O_NONBLOCK)
-	fcntl(wrwake, _F_SETFD, _FD_CLOEXEC)
+	rdwake = r
+	wrwake = w
 
 	// Pre-allocate array of pollfd structures for poll.
 	pfds = make([]pollfd, 1, 128)

src/runtime/os2_aix.go

@@ -425,9 +425,10 @@ func closefd(fd int32) int32 {
 }
 
 //go:nosplit
-func pipe(fd *int32) int32 {
-	r, _ := syscall1(&libc_pipe, uintptr(unsafe.Pointer(fd)))
-	return int32(r)
+func pipe() (r, w int32, errno int32) {
+	var p [2]int32
+	_, err := syscall1(&libc_pipe, uintptr(noescape(unsafe.Pointer(&p[0]))))
+	return p[0], p[1], int32(err)
 }
 
 // mmap calls the mmap system call.

src/runtime/os_aix.go

@@ -357,3 +357,20 @@ func setupSystemConf() {
 		cpu.HWCap2 |= cpu.PPC_FEATURE2_ARCH_3_00
 	}
 }
+
+//go:nosplit
+func fcntl(fd, cmd int32, arg uintptr) int32 {
+	r, _ := syscall3(&libc_fcntl, uintptr(fd), uintptr(cmd), arg)
+	return int32(r)
+}
+
+//go:nosplit
+func closeonexec(fd int32) {
+	fcntl(fd, _F_SETFD, _FD_CLOEXEC)
+}
+
+//go:nosplit
+func setNonblock(fd int32) {
+	flags := fcntl(fd, _F_GETFL, 0)
+	fcntl(fd, _F_SETFL, uintptr(flags|_O_NONBLOCK))
+}

src/runtime/os_dragonfly.go

@@ -54,6 +54,9 @@ func kqueue() int32
 //go:noescape
 func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32
 func closeonexec(fd int32)
+func setNonblock(fd int32)
+
+func pipe() (r, w int32, errno int32)
 
 const stackSystem = 0
 

src/runtime/os_freebsd.go

@@ -39,6 +39,7 @@ func kqueue() int32
 //go:noescape
 func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32
 func closeonexec(fd int32)
+func setNonblock(fd int32)
 
 // From FreeBSD's <sys/sysctl.h>
 const (

src/runtime/os_linux.go

@@ -372,6 +372,8 @@ func raiseproc(sig uint32)
 func sched_getaffinity(pid, len uintptr, buf *byte) int32
 func osyield()
 
+func setNonblock(fd int32)
+
 //go:nosplit
 //go:nowritebarrierrec
 func setsig(i uint32, fn uintptr) {

src/runtime/os_netbsd.go

@@ -73,6 +73,7 @@ func kqueue() int32
 //go:noescape
 func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32
 func closeonexec(fd int32)
+func setNonblock(fd int32)
 
 const (
 	_ESRCH     = 3

src/runtime/os_openbsd.go

@@ -61,6 +61,7 @@ func kqueue() int32
 //go:noescape
 func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32
 func closeonexec(fd int32)
+func setNonblock(fd int32)
 
 const (
 	_ESRCH       = 3

src/runtime/sys_dragonfly_amd64.s

@@ -108,6 +108,21 @@ TEXT runtime·read(SB),NOSPLIT,$-8
 	MOVL	AX, ret+24(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	MOVL	$42, AX
+	SYSCALL
+	JCC	pipeok
+	MOVL	$-1,r+0(FP)
+	MOVL	$-1,w+4(FP)
+	MOVL	AX, errno+8(FP)
+	RET
+pipeok:
+	MOVL	AX, r+0(FP)
+	MOVL	DX, w+4(FP)
+	MOVL	$0, errno+8(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT,$-8
 	MOVQ	fd+0(FP), DI		// arg 1 fd
 	MOVQ	p+8(FP), SI		// arg 2 buf
@@ -371,3 +386,18 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	MOVL	$92, AX		// fcntl
 	SYSCALL
 	RET
+
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
+	MOVL    fd+0(FP), DI  // fd
+	MOVQ    $3, SI  // F_GETFL
+	MOVQ    $0, DX
+	MOVL	$92, AX // fcntl
+	SYSCALL
+	MOVL	fd+0(FP), DI // fd
+	MOVQ	$4, SI // F_SETFL
+	MOVQ	$4, DX // O_NONBLOCK
+	ORL	AX, DX
+	MOVL	$92, AX // fcntl
+	SYSCALL
+	RET

src/runtime/sys_freebsd_386.s

@@ -97,6 +97,32 @@ TEXT runtime·read(SB),NOSPLIT,$-4
 	MOVL	AX, ret+12(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$8-12
+	MOVL	$42, AX
+	INT	$0x80
+	JAE	ok
+	MOVL	$0, r+0(FP)
+	MOVL	$0, w+4(FP)
+	MOVL	AX, errno+8(FP)
+	RET
+ok:
+	MOVL	AX, r+0(FP)
+	MOVL	DX, w+4(FP)
+	MOVL	$0, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$12-16
+	MOVL	$542, AX
+	LEAL	r+4(FP), BX
+	MOVL	BX, 4(SP)
+	MOVL	flags+0(FP), BX
+	MOVL	BX, 8(SP)
+	INT	$0x80
+	MOVL	AX, errno+12(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT,$-4
 	MOVL	$4, AX
 	INT	$0x80
@@ -412,6 +438,23 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$32
 	NEGL	AX
 	RET
 
+// func runtime·setNonblock(fd int32)
+TEXT runtime·setNonblock(SB),NOSPLIT,$16-4
+	MOVL	$92, AX // fcntl
+	MOVL	fd+0(FP), BX // fd
+	MOVL	BX, 4(SP)
+	MOVL	$3, 8(SP) // F_GETFL
+	MOVL	$0, 12(SP)
+	INT	$0x80
+	MOVL	fd+0(FP), BX // fd
+	MOVL	BX, 4(SP)
+	MOVL	$4, 8(SP) // F_SETFL
+	ORL	$4, AX // O_NONBLOCK
+	MOVL	AX, 12(SP)
+	MOVL	$92, AX // fcntl
+	INT	$0x80
+	RET
+
 // func cpuset_getaffinity(level int, which int, id int64, size int, mask *byte) int32
 TEXT runtime·cpuset_getaffinity(SB), NOSPLIT, $0-28
 	MOVL	$487, AX

src/runtime/sys_freebsd_amd64.s

@@ -97,6 +97,30 @@ TEXT runtime·read(SB),NOSPLIT,$-8
 	MOVL	AX, ret+24(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	MOVL	$42, AX
+	SYSCALL
+	JCC	ok
+	MOVL	$0, r+0(FP)
+	MOVL	$0, w+4(FP)
+	MOVL	AX, errno+8(FP)
+	RET
+ok:
+	MOVL	AX, r+0(FP)
+	MOVL	DX, w+4(FP)
+	MOVL	$0, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$0-20
+	LEAQ	r+8(FP), DI
+	MOVL	flags+0(FP), SI
+	MOVL	$542, AX
+	SYSCALL
+	MOVL	AX, errno+16(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT,$-8
 	MOVQ	fd+0(FP), DI		// arg 1 fd
 	MOVQ	p+8(FP), SI		// arg 2 buf
@@ -447,6 +471,21 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	SYSCALL
 	RET
 
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
+	MOVL    fd+0(FP), DI  // fd
+	MOVQ    $3, SI  // F_GETFL
+	MOVQ    $0, DX
+	MOVL	$92, AX // fcntl
+	SYSCALL
+	MOVL	fd+0(FP), DI // fd
+	MOVQ	$4, SI // F_SETFL
+	MOVQ	$4, DX // O_NONBLOCK
+	ORL	AX, DX
+	MOVL	$92, AX // fcntl
+	SYSCALL
+	RET
+
 // func cpuset_getaffinity(level int, which int, id int64, size int, mask *byte) int32
 TEXT runtime·cpuset_getaffinity(SB), NOSPLIT, $0-44
 	MOVQ	level+0(FP), DI

src/runtime/sys_freebsd_arm.s

@@ -20,6 +20,7 @@
 #define SYS_close (SYS_BASE + 6)
 #define SYS_getpid (SYS_BASE + 20)
 #define SYS_kill (SYS_BASE + 37)
+#define SYS_pipe (SYS_BASE + 42)
 #define SYS_sigaltstack (SYS_BASE + 53)
 #define SYS_munmap (SYS_BASE + 73)
 #define SYS_madvise (SYS_BASE + 75)
@@ -40,6 +41,7 @@
 #define SYS_thr_new (SYS_BASE + 455)
 #define SYS_mmap (SYS_BASE + 477)
 #define SYS_cpuset_getaffinity (SYS_BASE + 487)
+#define SYS_pipe2 (SYS_BASE + 542)
 
 TEXT runtime·sys_umtx_op(SB),NOSPLIT,$0
 	MOVW addr+0(FP), R0
@@ -119,6 +121,32 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
 	MOVW	R0, ret+12(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	MOVW	$SYS_pipe, R7
+	SWI	$0
+	BCC	ok
+	MOVW	$0, R1
+	MOVW	R1, r+0(FP)
+	MOVW	R1, w+4(FP)
+	MOVW	R0, errno+8(FP)
+	RET
+ok:
+	MOVW	R0, r+0(FP)
+	MOVW	R1, w+4(FP)
+	MOVW	$0, R1
+	MOVW	R1, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$0-16
+	MOVW	$r+4(FP), R0
+	MOVW	flags+0(FP), R1
+	MOVW	$SYS_pipe2, R7
+	SWI	$0
+	MOVW	R0, errno+12(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0
 	MOVW fd+0(FP), R0	// arg 1 fd
 	MOVW p+4(FP), R1	// arg 2 buf
@@ -371,6 +399,20 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	SWI $0
 	RET
 
+// func runtime·setNonblock(fd int32)
+TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
+	MOVW	fd+0(FP), R0	// fd
+	MOVW	$3, R1	// F_GETFL
+	MOVW	$0, R2
+	MOVW	$SYS_fcntl, R7
+	SWI	$0
+	ORR	$0x4, R0, R2	// O_NONBLOCK
+	MOVW	fd+0(FP), R0	// fd
+	MOVW	$4, R1	// F_SETFL
+	MOVW	$SYS_fcntl, R7
+	SWI	$0
+	RET
+
 // TODO: this is only valid for ARMv7+
 TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0
 	B	runtime·armPublicationBarrier(SB)

src/runtime/sys_linux_386.s

@@ -32,6 +32,7 @@
 #define SYS_getpid		20
 #define SYS_access		33
 #define SYS_kill		37
+#define SYS_pipe		42
 #define SYS_brk 		45
 #define SYS_fcntl		55
 #define SYS_munmap		91
@@ -58,6 +59,7 @@
 #define SYS_clock_gettime	265
 #define SYS_tgkill		270
 #define SYS_epoll_create1	329
+#define SYS_pipe2		331
 
 TEXT runtime·exit(SB),NOSPLIT,$0
 	MOVL	$SYS_exit_group, AX
@@ -131,6 +133,23 @@ TEXT runtime·read(SB),NOSPLIT,$0
 	MOVL	AX, ret+12(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	MOVL	$SYS_pipe, AX
+	LEAL	r+0(FP), BX
+	INVOKE_SYSCALL
+	MOVL	AX, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$0-16
+	MOVL	$SYS_pipe2, AX
+	LEAL	r+4(FP), BX
+	MOVL	flags+0(FP), CX
+	INVOKE_SYSCALL
+	MOVL	AX, errno+12(FP)
+	RET
+
 TEXT runtime·usleep(SB),NOSPLIT,$8
 	MOVL	$0, DX
 	MOVL	usec+0(FP), AX
@@ -695,6 +714,21 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	INVOKE_SYSCALL
 	RET
 
+// func runtime·setNonblock(fd int32)
+TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
+	MOVL	$SYS_fcntl, AX
+	MOVL	fd+0(FP), BX // fd
+	MOVL	$3, CX // F_GETFL
+	MOVL	$0, DX
+	INVOKE_SYSCALL
+	MOVL	fd+0(FP), BX // fd
+	MOVL	$4, CX // F_SETFL
+	MOVL	$0x800, DX // O_NONBLOCK
+	ORL	AX, DX
+	MOVL	$SYS_fcntl, AX
+	INVOKE_SYSCALL
+	RET
+
 // int access(const char *name, int mode)
 TEXT runtime·access(SB),NOSPLIT,$0
 	MOVL	$SYS_access, AX

src/runtime/sys_linux_amd64.s

@@ -21,6 +21,7 @@
 #define SYS_rt_sigaction	13
 #define SYS_rt_sigprocmask	14
 #define SYS_rt_sigreturn	15
+#define SYS_pipe		22
 #define SYS_sched_yield 	24
 #define SYS_mincore		27
 #define SYS_madvise		28
@@ -46,6 +47,7 @@
 #define SYS_faccessat		269
 #define SYS_epoll_pwait		281
 #define SYS_epoll_create1	291
+#define SYS_pipe2		293
 
 TEXT runtime·exit(SB),NOSPLIT,$0-4
 	MOVL	code+0(FP), DI
@@ -113,6 +115,23 @@ TEXT runtime·read(SB),NOSPLIT,$0-28
 	MOVL	AX, ret+24(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	LEAQ	r+0(FP), DI
+	MOVL	$SYS_pipe, AX
+	SYSCALL
+	MOVL	AX, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$0-20
+	LEAQ	r+8(FP), DI
+	MOVL	flags+0(FP), SI
+	MOVL	$SYS_pipe2, AX
+	SYSCALL
+	MOVL	AX, errno+16(FP)
+	RET
+
 TEXT runtime·usleep(SB),NOSPLIT,$16
 	MOVL	$0, DX
 	MOVL	usec+0(FP), AX
@@ -682,6 +701,20 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	SYSCALL
 	RET
 
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
+	MOVL    fd+0(FP), DI  // fd
+	MOVQ    $3, SI  // F_GETFL
+	MOVQ    $0, DX
+	MOVL	$SYS_fcntl, AX
+	SYSCALL
+	MOVL	fd+0(FP), DI // fd
+	MOVQ	$4, SI // F_SETFL
+	MOVQ	$0x800, DX // O_NONBLOCK
+	ORL	AX, DX
+	MOVL	$SYS_fcntl, AX
+	SYSCALL
+	RET
 
 // int access(const char *name, int mode)
 TEXT runtime·access(SB),NOSPLIT,$0

src/runtime/sys_linux_arm.s

@@ -23,6 +23,7 @@
 #define SYS_close (SYS_BASE + 6)
 #define SYS_getpid (SYS_BASE + 20)
 #define SYS_kill (SYS_BASE + 37)
+#define SYS_pipe (SYS_BASE + 42)
 #define SYS_clone (SYS_BASE + 120)
 #define SYS_rt_sigreturn (SYS_BASE + 173)
 #define SYS_rt_sigaction (SYS_BASE + 174)
@@ -45,6 +46,7 @@
 #define SYS_epoll_ctl (SYS_BASE + 251)
 #define SYS_epoll_wait (SYS_BASE + 252)
 #define SYS_epoll_create1 (SYS_BASE + 357)
+#define SYS_pipe2 (SYS_BASE + 359)
 #define SYS_fcntl (SYS_BASE + 55)
 #define SYS_access (SYS_BASE + 33)
 #define SYS_connect (SYS_BASE + 283)
@@ -99,6 +101,23 @@ TEXT runtime·read(SB),NOSPLIT,$0
 	MOVW	R0, ret+12(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	MOVW	$r+0(FP), R0
+	MOVW	$SYS_pipe, R7
+	SWI	$0
+	MOVW	R0, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$0-16
+	MOVW	$r+4(FP), R0
+	MOVW	flags+0(FP), R1
+	MOVW	$SYS_pipe2, R7
+	SWI	$0
+	MOVW	R0, errno+12(FP)
+	RET
+
 TEXT runtime·exit(SB),NOSPLIT|NOFRAME,$0
 	MOVW	code+0(FP), R0
 	MOVW	$SYS_exit_group, R7
@@ -567,6 +586,20 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	SWI	$0
 	RET
 
+// func runtime·setNonblock(fd int32)
+TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
+	MOVW	fd+0(FP), R0	// fd
+	MOVW	$3, R1	// F_GETFL
+	MOVW	$0, R2
+	MOVW	$SYS_fcntl, R7
+	SWI	$0
+	ORR	$0x800, R0, R2	// O_NONBLOCK
+	MOVW	fd+0(FP), R0	// fd
+	MOVW	$4, R1	// F_SETFL
+	MOVW	$SYS_fcntl, R7
+	SWI	$0
+	RET
+
 // b __kuser_get_tls @ 0xffff0fe0
 TEXT runtime·read_tls_fallback(SB),NOSPLIT|NOFRAME,$0
 	MOVW	$0xffff0fe0, R0

src/runtime/sys_linux_arm64.s

@@ -20,6 +20,7 @@
 #define SYS_write		64
 #define SYS_openat		56
 #define SYS_close		57
+#define SYS_pipe2		59
 #define SYS_fcntl		25
 #define SYS_nanosleep		101
 #define SYS_mmap		222
@@ -117,6 +118,24 @@ done:
 	MOVW	R0, ret+24(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT|NOFRAME,$0-12
+	ADD	$8, RSP, R0
+	MOVW	$0, R1
+	MOVW	$SYS_pipe2, R8
+	SVC
+	MOVW	R0, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT|NOFRAME,$0-20
+	ADD	$16, RSP, R0
+	MOVW	flags+0(FP), R1
+	MOVW	$SYS_pipe2, R8
+	SVC
+	MOVW	R0, errno+16(FP)
+	RET
+
 TEXT runtime·usleep(SB),NOSPLIT,$24-4
 	MOVWU	usec+0(FP), R3
 	MOVD	R3, R5
@@ -605,6 +624,21 @@ TEXT runtime·closeonexec(SB),NOSPLIT|NOFRAME,$0
 	SVC
 	RET
 
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT|NOFRAME,$0-4
+	MOVW	fd+0(FP), R0 // fd
+	MOVD	$3, R1	// F_GETFL
+	MOVD	$0, R2
+	MOVD	$SYS_fcntl, R8
+	SVC
+	MOVD	$0x800, R2 // O_NONBLOCK
+	EOR	R0, R2
+	MOVW	fd+0(FP), R0 // fd
+	MOVD	$4, R1	// F_SETFL
+	MOVD	$SYS_fcntl, R8
+	SVC
+	RET
+
 // int access(const char *name, int mode)
 TEXT runtime·access(SB),NOSPLIT,$0-20
 	MOVD	$AT_FDCWD, R0

src/runtime/sys_linux_mips64x.s

@@ -19,6 +19,7 @@
 #define SYS_read		5000
 #define SYS_write		5001
 #define SYS_close		5003
+#define SYS_pipe		5021
 #define SYS_getpid		5038
 #define SYS_kill		5060
 #define SYS_fcntl		5080
@@ -46,6 +47,7 @@
 #define SYS_clock_gettime	5222
 #define SYS_epoll_create1	5285
 #define SYS_brk			5012
+#define SYS_pipe2		5287
 
 TEXT runtime·exit(SB),NOSPLIT|NOFRAME,$0-4
 	MOVW	code+0(FP), R4
@@ -110,6 +112,23 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0-28
 	MOVW	R2, ret+24(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT|NOFRAME,$0-12
+	MOVV	$r+0(FP), R4
+	MOVV	$SYS_pipe, R2
+	SYSCALL
+	MOVW	R2, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT|NOFRAME,$0-20
+	MOVV	$r+8(FP), R4
+	MOVW	flags+0(FP), R5
+	MOVV	$SYS_pipe2, R2
+	SYSCALL
+	MOVW	R2, errno+16(FP)
+	RET
+
 TEXT runtime·usleep(SB),NOSPLIT,$16-4
 	MOVWU	usec+0(FP), R3
 	MOVV	R3, R5
@@ -454,6 +473,21 @@ TEXT runtime·closeonexec(SB),NOSPLIT|NOFRAME,$0
 	SYSCALL
 	RET
 
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT|NOFRAME,$0-4
+	MOVW	fd+0(FP), R4 // fd
+	MOVV	$3, R5	// F_GETFL
+	MOVV	$0, R6
+	MOVV	$SYS_fcntl, R2
+	SYSCALL
+	MOVW	$0x80, R6 // O_NONBLOCK
+	OR	R2, R6
+	MOVW	fd+0(FP), R4 // fd
+	MOVV	$4, R5	// F_SETFL
+	MOVV	$SYS_fcntl, R2
+	SYSCALL
+	RET
+
 // func sbrk0() uintptr
 TEXT runtime·sbrk0(SB),NOSPLIT|NOFRAME,$0-8
 	// Implemented as brk(NULL).

src/runtime/sys_linux_mipsx.s

@@ -20,6 +20,7 @@
 #define SYS_close		4006
 #define SYS_getpid		4020
 #define SYS_kill		4037
+#define SYS_pipe		4042
 #define SYS_brk			4045
 #define SYS_fcntl		4055
 #define SYS_mmap		4090
@@ -44,6 +45,7 @@
 #define SYS_clock_gettime	4263
 #define SYS_tgkill		4266
 #define SYS_epoll_create1	4326
+#define SYS_pipe2		4328
 
 TEXT runtime·exit(SB),NOSPLIT,$0-4
 	MOVW	code+0(FP), R4
@@ -108,6 +110,23 @@ TEXT runtime·read(SB),NOSPLIT,$0-16
 	MOVW	R2, ret+12(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	MOVW	$r+0(FP), R4
+	MOVW	$SYS_pipe, R2
+	SYSCALL
+	MOVW	R2, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$0-16
+	MOVW	$r+4(FP), R4
+	MOVW	flags+0(FP), R5
+	MOVW	$SYS_pipe2, R2
+	SYSCALL
+	MOVW	R2, errno+12(FP)
+	RET
+
 TEXT runtime·usleep(SB),NOSPLIT,$28-4
 	MOVW	usec+0(FP), R3
 	MOVW	R3, R5
@@ -487,6 +506,21 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0-4
 	SYSCALL
 	RET
 
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
+	MOVW	fd+0(FP), R4 // fd
+	MOVW	$3, R5	// F_GETFL
+	MOVW	$0, R6
+	MOVW	$SYS_fcntl, R2
+	SYSCALL
+	MOVW	$0x80, R6 // O_NONBLOCK
+	OR	R2, R6
+	MOVW	fd+0(FP), R4 // fd
+	MOVW	$4, R5	// F_SETFL
+	MOVW	$SYS_fcntl, R2
+	SYSCALL
+	RET
+
 // func sbrk0() uintptr
 TEXT runtime·sbrk0(SB),NOSPLIT,$0-4
 	// Implemented as brk(NULL).

src/runtime/sys_linux_ppc64x.s

@@ -21,6 +21,7 @@
 #define SYS_close		  6
 #define SYS_getpid		 20
 #define SYS_kill		 37
+#define SYS_pipe		 42
 #define SYS_brk			 45
 #define SYS_fcntl		 55
 #define SYS_mmap		 90
@@ -45,6 +46,7 @@
 #define SYS_clock_gettime	246
 #define SYS_tgkill		250
 #define SYS_epoll_create1	315
+#define SYS_pipe2		317
 
 TEXT runtime·exit(SB),NOSPLIT|NOFRAME,$0-4
 	MOVW	code+0(FP), R3
@@ -100,6 +102,21 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0-28
 	MOVW	R3, ret+24(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT|NOFRAME,$0-12
+	ADD	$FIXED_FRAME, R1, R3
+	SYSCALL	$SYS_pipe
+	MOVW	R3, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT|NOFRAME,$0-20
+	ADD	$FIXED_FRAME+8, R1, R3
+	MOVW	flags+0(FP), R4
+	SYSCALL	$SYS_pipe2
+	MOVW	R3, errno+16(FP)
+	RET
+
 TEXT runtime·usleep(SB),NOSPLIT,$16-4
 	MOVW	usec+0(FP), R3
 	MOVD	R3, R5
@@ -612,6 +629,18 @@ TEXT runtime·closeonexec(SB),NOSPLIT|NOFRAME,$0
 	SYSCALL	$SYS_fcntl
 	RET
 
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT|NOFRAME,$0-4
+	MOVW	fd+0(FP), R3 // fd
+	MOVD	$3, R4	// F_GETFL
+	MOVD	$0, R5
+	SYSCALL	$SYS_fcntl
+	OR	$0x800, R3, R5 // O_NONBLOCK
+	MOVW	fd+0(FP), R3 // fd
+	MOVD	$4, R4	// F_SETFL
+	SYSCALL	$SYS_fcntl
+	RET
+
 // func sbrk0() uintptr
 TEXT runtime·sbrk0(SB),NOSPLIT|NOFRAME,$0
 	// Implemented as brk(NULL).

src/runtime/sys_linux_s390x.s

@@ -16,6 +16,7 @@
 #define SYS_close                 6
 #define SYS_getpid               20
 #define SYS_kill                 37
+#define SYS_pipe		 42
 #define SYS_brk			 45
 #define SYS_fcntl                55
 #define SYS_mmap                 90
@@ -39,6 +40,7 @@
 #define SYS_epoll_ctl           250
 #define SYS_epoll_wait          251
 #define SYS_clock_gettime       260
+#define SYS_pipe2		325
 #define SYS_epoll_create1       327
 
 TEXT runtime·exit(SB),NOSPLIT|NOFRAME,$0-4
@@ -104,6 +106,23 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0-28
 	MOVW	R2, ret+24(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT|NOFRAME,$0-12
+	MOVD	$r+0(FP), R2
+	MOVW	$SYS_pipe, R1
+	SYSCALL
+	MOVW	R2, errno+8(FP)
+	RET
+
+// func pipe2() (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT|NOFRAME,$0-20
+	MOVD	$r+8(FP), R2
+	MOVW	flags+0(FP), R3
+	MOVW	$SYS_pipe2, R1
+	SYSCALL
+	MOVW	R2, errno+16(FP)
+	RET
+
 TEXT runtime·usleep(SB),NOSPLIT,$16-4
 	MOVW	usec+0(FP), R2
 	MOVD	R2, R4
@@ -441,6 +460,21 @@ TEXT runtime·closeonexec(SB),NOSPLIT|NOFRAME,$0
 	SYSCALL
 	RET
 
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT|NOFRAME,$0-4
+	MOVW	fd+0(FP), R2 // fd
+	MOVD	$3, R3	// F_GETFL
+	XOR	R4, R4
+	MOVW	$SYS_fcntl, R1
+	SYSCALL
+	MOVD	$0x800, R4 // O_NONBLOCK
+	OR	R2, R4
+	MOVW	fd+0(FP), R2 // fd
+	MOVD	$4, R3	// F_SETFL
+	MOVW	$SYS_fcntl, R1
+	SYSCALL
+	RET
+
 // func sbrk0() uintptr
 TEXT runtime·sbrk0(SB),NOSPLIT|NOFRAME,$0-8
 	// Implemented as brk(NULL).

src/runtime/sys_netbsd_386.s

@@ -87,6 +87,32 @@ TEXT runtime·read(SB),NOSPLIT,$-4
 	MOVL	AX, ret+12(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	MOVL	$42, AX
+	INT	$0x80
+	JCC	pipeok
+	MOVL	$-1, r+0(FP)
+	MOVL	$-1, w+4(FP)
+	MOVL	AX, errno+8(FP)
+	RET
+pipeok:
+	MOVL	AX, r+0(FP)
+	MOVL	DX, w+4(FP)
+	MOVL	$0, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$12-16
+	MOVL	$453, AX
+	LEAL	r+4(FP), BX
+	MOVL	BX, 4(SP)
+	MOVL	flags+0(FP), BX
+	MOVL	BX, 8(SP)
+	INT	$0x80
+	MOVL	AX, errno+12(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT,$-4
 	MOVL	$SYS_write, AX
 	INT	$0x80
@@ -455,3 +481,20 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$32
 	JAE	2(PC)
 	NEGL	AX
 	RET
+
+// func runtime·setNonblock(fd int32)
+TEXT runtime·setNonblock(SB),NOSPLIT,$16-4
+	MOVL	$92, AX // fcntl
+	MOVL	fd+0(FP), BX // fd
+	MOVL	BX, 4(SP)
+	MOVL	$3, 8(SP) // F_GETFL
+	MOVL	$0, 12(SP)
+	INT	$0x80
+	MOVL	fd+0(FP), BX // fd
+	MOVL	BX, 4(SP)
+	MOVL	$4, 8(SP) // F_SETFL
+	ORL	$4, AX // O_NONBLOCK
+	MOVL	AX, 12(SP)
+	MOVL	$92, AX // fcntl
+	INT	$0x80
+	RET

src/runtime/sys_netbsd_amd64.s

@@ -158,6 +158,30 @@ TEXT runtime·read(SB),NOSPLIT,$-8
 	MOVL	AX, ret+24(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	MOVL	$42, AX
+	SYSCALL
+	JCC	pipeok
+	MOVL	$-1, r+0(FP)
+	MOVL	$-1, w+4(FP)
+	MOVL	AX, errno+8(FP)
+	RET
+pipeok:
+	MOVL	AX, r+0(FP)
+	MOVL	DX, w+4(FP)
+	MOVL	$0, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$0-20
+	LEAQ	r+8(FP), DI
+	MOVL	flags+0(FP), SI
+	MOVL	$453, AX
+	SYSCALL
+	MOVL	AX, errno+16(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT,$-8
 	MOVQ	fd+0(FP), DI		// arg 1 - fd
 	MOVQ	p+8(FP), SI		// arg 2 - buf
@@ -429,3 +453,18 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	MOVL	$SYS_fcntl, AX
 	SYSCALL
 	RET
+
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
+	MOVL    fd+0(FP), DI  // fd
+	MOVQ    $3, SI  // F_GETFL
+	MOVQ    $0, DX
+	MOVL	$92, AX // fcntl
+	SYSCALL
+	MOVL	fd+0(FP), DI // fd
+	MOVQ	$4, SI // F_SETFL
+	MOVQ	$4, DX // O_NONBLOCK
+	ORL	AX, DX
+	MOVL	$92, AX // fcntl
+	SYSCALL
+	RET

src/runtime/sys_netbsd_arm.s

@@ -96,6 +96,30 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
 	MOVW	R0, ret+12(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	SWI $0xa0002a
+	BCC pipeok
+	MOVW $-1,R2
+	MOVW R2, r+0(FP)
+	MOVW R2, w+4(FP)
+	MOVW R0, errno+8(FP)
+	RET
+pipeok:
+	MOVW $0, R2
+	MOVW R0, r+0(FP)
+	MOVW R1, w+4(FP)
+	MOVW R2, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$0-16
+	MOVW $r+4(FP), R0
+	MOVW flags+0(FP), R1
+	SWI $0xa001c5
+	MOVW R0, errno+12(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0
 	MOVW	fd+0(FP), R0	// arg 1 - fd
 	MOVW	p+4(FP), R1	// arg 2 - buf
@@ -385,6 +409,18 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	SWI $SYS_fcntl
 	RET
 
+// func runtime·setNonblock(fd int32)
+TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
+	MOVW fd+0(FP), R0	// fd
+	MOVW $3, R1	// F_GETFL
+	MOVW $0, R2
+	SWI $0xa0005c	// sys_fcntl
+	ORR $0x4, R0, R2	// O_NONBLOCK
+	MOVW fd+0(FP), R0	// fd
+	MOVW $4, R1	// F_SETFL
+	SWI $0xa0005c	// sys_fcntl
+	RET
+
 // TODO: this is only valid for ARMv7+
 TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0
 	B	runtime·armPublicationBarrier(SB)

src/runtime/sys_netbsd_arm64.s

@@ -14,6 +14,9 @@
 #define CLOCK_MONOTONIC		3
 #define FD_CLOEXEC		1
 #define F_SETFD			2
+#define F_GETFL			3
+#define F_SETFL			4
+#define O_NONBLOCK		4
 
 #define SYS_exit			1
 #define SYS_read			3
@@ -43,6 +46,7 @@
 #define SYS___clock_gettime50		427
 #define SYS___nanosleep50		430
 #define SYS___kevent50			435
+#define SYS_pipe2			453
 #define SYS_openat			468
 #define SYS____lwp_park60		478
 
@@ -146,6 +150,33 @@ ok:
 	MOVW	R0, ret+24(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT|NOFRAME,$0-12
+	MOVW	$0, R0
+	SVC	$SYS_pipe2
+	BCC	pipeok
+	MOVW	$-1,R1
+	MOVW	R1, r+0(FP)
+	MOVW	R1, w+4(FP)
+	NEG	R0, R0
+	MOVW	R0, errno+8(FP)
+	RET
+pipeok:
+	MOVW	R0, r+0(FP)
+	MOVW	R1, w+4(FP)
+	MOVW	ZR, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT|NOFRAME,$0-20
+	ADD	$8, RSP, R0
+	MOVW	flags+0(FP), R1
+	SVC	$SYS_pipe2
+	BCC	2(PC)
+	NEG	R0, R0
+	MOVW	R0, errno+16(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT,$-8
 	MOVD	fd+0(FP), R0		// arg 1 - fd
 	MOVD	p+8(FP), R1		// arg 2 - buf
@@ -431,3 +462,16 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	MOVW	$FD_CLOEXEC, R2
 	SVC	$SYS_fcntl
 	RET
+
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT|NOFRAME,$0-4
+	MOVW	fd+0(FP), R0		// arg 1 - fd
+	MOVD	$F_GETFL, R1		// arg 2 - cmd
+	MOVD	$0, R2			// arg 3
+	SVC	$SYS_fcntl
+	MOVD	$O_NONBLOCK, R2
+	EOR	R0, R2			// arg 3 - flags
+	MOVW	fd+0(FP), R0		// arg 1 - fd
+	MOVD	$F_SETFL, R1		// arg 2 - cmd
+	SVC	$SYS_fcntl
+	RET

src/runtime/sys_openbsd_386.s

@@ -50,6 +50,26 @@ TEXT runtime·read(SB),NOSPLIT,$-4
 	MOVL	AX, ret+12(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$8-12
+	MOVL	$263, AX
+	LEAL	r+0(FP), BX
+	MOVL	BX, 4(SP)
+	INT	$0x80
+	MOVL	AX, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$12-16
+	MOVL	$101, AX
+	LEAL	r+4(FP), BX
+	MOVL	BX, 4(SP)
+	MOVL	flags+0(FP), BX
+	MOVL	BX, 8(SP)
+	INT	$0x80
+	MOVL	AX, errno+12(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT,$-4
 	MOVL	$4, AX			// sys_write
 	INT	$0x80
@@ -416,4 +436,21 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$32
 	NEGL	AX
 	RET
 
+// func runtime·setNonblock(fd int32)
+TEXT runtime·setNonblock(SB),NOSPLIT,$16-4
+	MOVL	$92, AX // fcntl
+	MOVL	fd+0(FP), BX // fd
+	MOVL	BX, 4(SP)
+	MOVL	$3, 8(SP) // F_GETFL
+	MOVL	$0, 12(SP)
+	INT	$0x80
+	MOVL	fd+0(FP), BX // fd
+	MOVL	BX, 4(SP)
+	MOVL	$4, 8(SP) // F_SETFL
+	ORL	$4, AX // O_NONBLOCK
+	MOVL	AX, 12(SP)
+	MOVL	$92, AX // fcntl
+	INT	$0x80
+	RET
+
 GLOBL runtime·tlsoffset(SB),NOPTR,$4

src/runtime/sys_openbsd_amd64.s

@@ -127,6 +127,23 @@ TEXT runtime·read(SB),NOSPLIT,$-8
 	MOVL	AX, ret+24(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	LEAQ	r+0(FP), DI
+	MOVL	$263, AX
+	SYSCALL
+	MOVL	AX, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$0-20
+	LEAQ	r+8(FP), DI
+	MOVL	flags+0(FP), SI
+	MOVL	$101, AX
+	SYSCALL
+	MOVL	AX, errno+16(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT,$-8
 	MOVQ	fd+0(FP), DI		// arg 1 - fd
 	MOVQ	p+8(FP), SI		// arg 2 - buf
@@ -378,3 +395,18 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	MOVL	$92, AX		// fcntl
 	SYSCALL
 	RET
+
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
+	MOVL    fd+0(FP), DI  // fd
+	MOVQ    $3, SI  // F_GETFL
+	MOVQ    $0, DX
+	MOVL	$92, AX // fcntl
+	SYSCALL
+	MOVL	fd+0(FP), DI // fd
+	MOVQ	$4, SI // F_SETFL
+	MOVQ	$4, DX // O_NONBLOCK
+	ORL	AX, DX
+	MOVL	$92, AX // fcntl
+	SYSCALL
+	RET

src/runtime/sys_openbsd_arm.s

@@ -59,6 +59,23 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
 	MOVW	R0, ret+12(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT,$0-12
+	MOVW	$r+0(FP), R0
+	MOVW	$263, R12
+	SWI	$0
+	MOVW	R0, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$0-16
+	MOVW	$r+4(FP), R0
+	MOVW	flags+0(FP), R1
+	MOVW	$101, R12
+	SWI	$0
+	MOVW	R0, errno+12(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0
 	MOVW	fd+0(FP), R0		// arg 1 - fd
 	MOVW	p+4(FP), R1		// arg 2 - buf
@@ -368,6 +385,20 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	SWI	$0
 	RET
 
+// func runtime·setNonblock(fd int32)
+TEXT runtime·setNonblock(SB),NOSPLIT,$0-4
+	MOVW	fd+0(FP), R0	// fd
+	MOVW	$3, R1	// F_GETFL
+	MOVW	$0, R2
+	MOVW	$92, R12
+	SWI	$0
+	ORR	$0x4, R0, R2	// O_NONBLOCK
+	MOVW	fd+0(FP), R0	// fd
+	MOVW	$4, R1	// F_SETFL
+	MOVW	$92, R12
+	SWI	$0
+	RET
+
 TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0
 	B	runtime·armPublicationBarrier(SB)
 

src/runtime/sys_openbsd_arm64.s

@@ -63,6 +63,28 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
 	MOVW	R0, ret+24(FP)
 	RET
 
+// func pipe() (r, w int32, errno int32)
+TEXT runtime·pipe(SB),NOSPLIT|NOFRAME,$0-12
+	MOVD	RSP, R0
+	MOVW	$0, R1
+	MOVD	$101, R8		// sys_pipe2
+	SVC
+	BCC	2(PC)
+	NEG	R0, R0
+	MOVW	R0, errno+8(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT|NOFRAME,$0-20
+	ADD	$8, RSP, R0
+	MOVW	flags+0(FP), R1
+	MOVD	$101, R8		// sys_pipe2
+	SVC
+	BCC	2(PC)
+	NEG	R0, R0
+	MOVW	R0, errno+16(FP)
+	RET
+
 TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0
 	MOVW	fd+0(FP), R0		// arg 1 - fd
 	MOVD	p+8(FP), R1		// arg 2 - buf
@@ -394,3 +416,18 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
 	MOVD	$92, R8			// sys_fcntl
 	SVC
 	RET
+
+// func runtime·setNonblock(int32 fd)
+TEXT runtime·setNonblock(SB),NOSPLIT|NOFRAME,$0-4
+	MOVW	fd+0(FP), R0		// arg 1 - fd
+	MOVD	$3, R1			// arg 2 - cmd (F_GETFL)
+	MOVD	$0, R2			// arg 3
+	MOVD	$92, R8			// sys_fcntl
+	SVC
+	MOVD	$0x800, R2		// O_NONBLOCK
+	EOR	R0, R2			// arg 3 - flags
+	MOVW	fd+0(FP), R0		// arg 1 - fd
+	MOVD	$4, R1			// arg 2 - cmd (F_SETFL)
+	MOVD	$92, R8			// sys_fcntl
+	SVC
+	RET