Function pump_io_round

run-command.c:1328–1403

};

static int pump_io_round(struct io_pump *slots, int nr, struct pollfd *pfd)
{
	int pollsize = 0;
	int i;

	for (i = 0; i < nr; i++) {
		struct io_pump *io = &slots[i];
		if (io->fd < 0)
			continue;
		pfd[pollsize].fd = io->fd;
		pfd[pollsize].events = io->type;
		io->pfd = &pfd[pollsize++];
	}

	if (!pollsize)
		return 0;

	if (poll(pfd, pollsize, -1) < 0) {
		if (errno == EINTR)
			return 1;
		die_errno("poll failed");
	}

	for (i = 0; i < nr; i++) {
		struct io_pump *io = &slots[i];

		if (io->fd < 0)
			continue;

		if (!(io->pfd->revents & (POLLOUT|POLLIN|POLLHUP|POLLERR|POLLNVAL)))
			continue;

		if (io->type == POLLOUT) {
			ssize_t len;

			/*
			 * Don't use xwrite() here. It loops forever on EAGAIN,
			 * and we're in our own poll() loop here.
			 *
			 * Note that we lose xwrite()'s handling of MAX_IO_SIZE
			 * and EINTR, so we have to implement those ourselves.
			 */
			len = write(io->fd, io->u.out.buf,
				    io->u.out.len <= MAX_IO_SIZE ?
				    io->u.out.len : MAX_IO_SIZE);
			if (len < 0) {
				if (errno != EINTR && errno != EAGAIN &&
				    errno != ENOSPC) {
					io->error = errno;
					close(io->fd);
					io->fd = -1;
				}
			} else {
				io->u.out.buf += len;
				io->u.out.len -= len;
				if (!io->u.out.len) {
					close(io->fd);
					io->fd = -1;