internal/poll: use atomic.Bool in DupCloseOnExec

Invert the meaning of the var to make use of the zero value.

Change-Id: If18db09896a67cb37cb3fe7dc0fb3493c6050a87
Reviewed-on: https://go-review.googlesource.com/c/go/+/463847
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
This commit is contained in:
Tobias Klauser 2023-02-01 11:29:28 +01:00 committed by Gopher Robot
parent 2a3c695c4b
commit 3c529c5367

View file

@ -688,13 +688,12 @@ func (fd *FD) Fstat(s *syscall.Stat_t) error {
})
}
// tryDupCloexec indicates whether F_DUPFD_CLOEXEC should be used.
// If the kernel doesn't support it, this is set to 0.
var tryDupCloexec = int32(1)
// dupCloexecUnsupported indicates whether F_DUPFD_CLOEXEC is supported by the kernel.
var dupCloexecUnsupported atomic.Bool
// DupCloseOnExec dups fd and marks it close-on-exec.
func DupCloseOnExec(fd int) (int, string, error) {
if syscall.F_DUPFD_CLOEXEC != 0 && atomic.LoadInt32(&tryDupCloexec) == 1 {
if syscall.F_DUPFD_CLOEXEC != 0 && !dupCloexecUnsupported.Load() {
r0, e1 := fcntl(fd, syscall.F_DUPFD_CLOEXEC, 0)
if e1 == nil {
return r0, "", nil
@ -704,7 +703,7 @@ func DupCloseOnExec(fd int) (int, string, error) {
// Old kernel, or js/wasm (which returns
// ENOSYS). Fall back to the portable way from
// now on.
atomic.StoreInt32(&tryDupCloexec, 0)
dupCloexecUnsupported.Store(true)
default:
return -1, "fcntl", e1
}