Re: POLLRDONCE optimisation for epoll users (was: epoll and half closed TCP connections)

From: Davide Libenzi <davidel@xmailserver.org>
To: Jamie Lokier <jamie@shareable.org>
Cc: "David S. Miller" <davem@redhat.com>,
	Eric Varsanyi <e0206@foo21.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	kuznet@ms2.inr.ac.ru
Subject: Re: POLLRDONCE optimisation for epoll users (was: epoll and half closed TCP connections)
Date: Sun, 13 Jul 2003 19:43:12 -0700 (PDT)	[thread overview]
Message-ID: <Pine.LNX.4.55.0307131940560.15022@bigblue.dev.mcafeelabs.com> (raw)
In-Reply-To: <Pine.LNX.4.55.0307131927580.15022@bigblue.dev.mcafeelabs.com>

On Sun, 13 Jul 2003, Davide Libenzi wrote:

> void my_process_read(my_data *d, unsigned int events) {
> 	int n, s;
>
> 	do {
> 		s = d->buffer_size - d->in_buffer;
> 		if ((n = read(d->fd, d->buffer + d->in_buffer, s)) > 0) {
> 			process_partial_buffer(d, s);
> 			d->in_buffer += s;
> 		}
> 	} while (n == s);
> 	if (s == -1 && errno != EAGAIN) {
> 		handle_read_error(d);
> 		return;
> 	}
> 	if (events & EPOLLRDHUP) {
> 		d->flags |= HANGUP;
> 		schedule_removal(d);
> 	}
> }

Ouch, this is obviously :

void my_process_read(my_data *d, unsigned int events) {
      int n, s;

      do {
		s = d->buffer_size - d->in_buffer;
		if ((n = read(d->fd, d->buffer + d->in_buffer, s)) > 0) {
			process_partial_buffer(d, n);
			d->in_buffer += n;
		}
	} while (n == s);
	if (n == -1 && errno != EAGAIN) {
		handle_read_error(d);
		return;
	}
	if (events & EPOLLRDHUP) {
		d->flags |= HANGUP;
		schedule_removal(d);
	}
}

- Davide