From 3c529c53676f809c7df55aac20e8b756462f0583 Mon Sep 17 00:00:00 2001 From: Tobias Klauser Date: Wed, 1 Feb 2023 11:29:28 +0100 Subject: [PATCH] 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 Run-TryBot: Tobias Klauser Auto-Submit: Tobias Klauser Reviewed-by: Ian Lance Taylor Reviewed-by: Michael Knyszek --- src/internal/poll/fd_unix.go | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/src/internal/poll/fd_unix.go b/src/internal/poll/fd_unix.go index 2786064d9f..5373052e65 100644 --- a/src/internal/poll/fd_unix.go +++ b/src/internal/poll/fd_unix.go @@ -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 } -- 2.50.0