From: Hagen Paul Pfeifer <hagen@jauu.net>
To: Jason Baron <jbaron@redhat.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>,
torvalds@linux-foundation.org,
LKML <linux-kernel@vger.kernel.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Lucas De Marchi <lucas.demarchi@profusion.mobi>,
Andrew Morton <akpm@linux-foundation.org>,
linux-fsdevel@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH Resend] epoll: add EPOLLEXCLUSIVE support
Date: Wed, 28 Mar 2012 21:58:48 +0200 [thread overview]
Message-ID: <20120328195848.GA5331@hell> (raw)
In-Reply-To: <20120328162108.GB2381@redhat.com>
* Jason Baron | 2012-03-28 12:21:08 [-0400]:
>Hmmm...Looking at ep_poll() it does an '__add_wait_queue_exclusive()'.
>So, I *think* epoll_wait() should do what you want, if you are waiting
>on the same epfd in all the threads.
>
>I think the case you are describing is where each thread does its own
>ep_create(), and then a subsequent epoll_wait() on the fd from the
>create?
>
>So, I *think* you can get what you want without adding this flag.
;) sorry:
epoll_wait returned
epoll_wait returned
epoll_wait returned
epoll_wait returned
epoll_wait returned
epoll_wait returned
epoll_wait returned
epoll_wait returned
epoll_wait returned
epoll_wait returned
minimal example:
>>>>>>>>>>>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <sys/epoll.h>
#define AMAX 16
static void *runner(void *args)
{
int fd = (int) *((int *) args);
struct epoll_event events[AMAX];
epoll_wait(fd, events, AMAX, -1);
write(1, "epoll_wait returned\n", 20);
return NULL;
}
int main(int ac, char **av)
{
int i, evfd, pipefd[2];
pthread_t thread_id[2];
struct epoll_event epoll_ev;
pipe(pipefd);
evfd = epoll_create(64);
memset(&epoll_ev, 0, sizeof(struct epoll_event));
epoll_ev.events = EPOLLIN | EPOLLPRI | EPOLLERR | EPOLLHUP;
epoll_ctl(evfd, EPOLL_CTL_ADD, pipefd[0], &epoll_ev);
for (i = 0; i < 10; i++)
pthread_create(&thread_id[0], NULL, runner, &evfd);
sleep(1);
close(pipefd[1]);
write(pipefd[0], "x", 1);
sleep(1);
return EXIT_SUCCESS;
}
<<<<<<<<<<<
Cheers, Hagen
next prev parent reply other threads:[~2012-03-28 20:07 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-28 13:57 [PATCH Resend] epoll: add EPOLLEXCLUSIVE support Hagen Paul Pfeifer
2012-03-28 14:09 ` richard -rw- weinberger
2012-03-28 16:21 ` Jason Baron
2012-03-28 19:58 ` Hagen Paul Pfeifer [this message]
2012-03-29 14:16 ` Jason Baron
2012-03-29 15:05 ` Hagen Paul Pfeifer
2012-03-29 15:53 ` Jason Baron
2012-03-29 16:32 ` Hagen Paul Pfeifer
2012-03-29 18:54 ` Jason Baron
2012-03-29 21:19 ` Hagen Paul Pfeifer
2012-04-05 22:30 ` Andy Lutomirski
2012-03-29 14:51 ` Hagen Paul Pfeifer
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