blob: 6cd3f91e8b2c49a7b2d35c6b71a741f1eac9d7e4 [file] [log] [blame]
// 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.
package poll
import (
_ "unsafe" // for go:linkname
// Fsync invokes SYS_FCNTL with SYS_FULLFSYNC because
// on OS X, SYS_FSYNC doesn't fully flush contents to disk.
// See Issue #26650 as well as the man page for fsync on OS X.
func (fd *FD) Fsync() error {
if err := fd.incref(); err != nil {
return err
defer fd.decref()
_, e1 := fcntl(fd.Sysfd, syscall.F_FULLFSYNC, 0)
return e1
// Use a helper function to call fcntl. This is defined in C in
// libgo/runtime.
//extern __go_fcntl_uintptr
func libc_fcntl(uintptr, uintptr, uintptr) (uintptr, uintptr)
func fcntl(fd int, cmd int, arg int) (int, error) {
r, e := libc_fcntl(uintptr(fd), uintptr(cmd), uintptr(arg))
if e != 0 {
return int(r), syscall.Errno(e)
return int(r), nil