syscall: add Dup3 on Linux

With dup3, we can avoid an extra system call on some machines
while holding syscall.ForkLock. Currently we have to
syscall.Dup + syscall.CloseOnExec.

On machines with Linux and a new enough kernel, this can just
be dup3.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/12170045
This commit is contained in:
Brad Fitzpatrick 2013-07-31 23:38:53 -07:00
parent 252c107f2f
commit c8d49cf56f
4 changed files with 31 additions and 0 deletions

View file

@ -310,6 +310,16 @@ func Dup2(oldfd int, newfd int) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Dup3(oldfd int, newfd int, flags int) (err error) {
_, _, e1 := RawSyscall(SYS_DUP3, uintptr(oldfd), uintptr(newfd), uintptr(flags))
if e1 != 0 {
err = e1
}
return
}
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func EpollCreate(size int) (fd int, err error) {
r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
fd = int(r0)