Function poll

src/cmd/utils.go:396–445

(pollFn pollFunc, eventFD int32, fds ...int32)

}

func poll(pollFn pollFunc, eventFD int32, fds ...int32) error {
	if len(fds) == 0 {
		panic("file descriptors not specified")
	}

	pollFDs := []unix.PollFd{
		{
			Fd:      eventFD,
			Events:  unix.POLLIN,
			Revents: 0,
		},
	}

	for _, fd := range fds {
		pollFD := unix.PollFd{Fd: fd, Events: unix.POLLIN, Revents: 0}
		pollFDs = append(pollFDs, pollFD)
	}

	for {
		if _, err := unix.Poll(pollFDs, -1); err != nil {
			if errors.Is(err, unix.EINTR) {
				logrus.Debugf("Failed to poll(2): %s: ignoring", err)
				continue
			}

			return fmt.Errorf("poll(2) failed: %w", err)
		}

		var err error

		if pollFDs[0].Revents&unix.POLLIN != 0 {
			logrus.Debug("Returned from eventfd: POLLIN")
			err = context.Canceled

			for {
				buffer := make([]byte, 8)
				if n, err := unix.Read(int(eventFD), buffer); n != len(buffer) || err != nil {
					break
				}
			}
		} else if pollFDs[0].Revents&unix.POLLNVAL != 0 {
			logrus.Debug("Returned from eventfd: POLLNVAL")
			err = context.Canceled
		}

		if err := pollFn(err, pollFDs[1:]); !errors.Is(err, errContinue) {
			return err
		}
	}
}

func resolveContainerAndImageNames(container, containerArg, distroCLI, imageCLI, releaseCLI string) (
	string, string, string, error,