Function waitForHWTS

timestamp/timestamp_linux.go:234–246

(connFd int)

type pollFunc func(fds []unix.PollFd, timeout *unix.Timespec, sigmask *unix.Sigset_t) (int, error)

func waitForHWTS(connFd int) error {
	return pollForHWTS(connFd, unix.Ppoll)
}

// pollForHWTS waits until the TX timestamp is ready, for at most TimeoutTXTS.
// unix.Poll is deliberately not used: it takes whole milliseconds as an int and
// passes anything negative to ppoll as "no timeout", so a lossy conversion there
// would reintroduce the unbounded wait this deadline exists to prevent.
func pollForHWTS(connFd int, poll pollFunc) error {
	fds := []unix.PollFd{{Fd: int32(connFd), Events: unix.POLLERR, Revents: 0}} //nolint:gosec // fd is always small
	// a restarted poll must share one deadline, otherwise every EINTR grants
	// another full TimeoutTXTS and the caller's attempt budget bounds nothing
	deadline := time.Now().Add(TimeoutTXTS)
	for {
		remaining := time.Until(deadline)
		if remaining <= 0 {