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Date: Fri, 31 Oct 2003 12:16:57 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: "cygwin AT cygwin DOT com" <cygwin AT cygwin DOT com>
Subject: Re: select() take 100% CPU with cygwin1.5.5-1 in WinXP/Win2000
Message-ID: <20031031111657.GA3918@cygbert.vinschen.de>
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References: <200310310514 DOT h9V5EMM04538 AT mx1 DOT redhat DOT com>
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On Fri, Oct 31, 2003 at 01:14:17PM +0800, zhouxin wrote:
> Cygwin implementation of select() take 100% CPU under multi-thread environment sometimes.
> [...]
>     if((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0){
>         fprintf(stderr, "cannot open socket for udp packet!\n");
>         exit(1);
>     }
>         
>     while(1){
>         struct timeval    tv;
>         fd_set            fds;
>         
>         FD_ZERO(&fds);
>         FD_SET(sockfd, &fds);
>         
>         tv.tv_sec  =  timeout;
>         tv.tv_usec = 0;
>         printf("select the socket_fd : %d, thread_id is : %d\n", 
>                 sockfd, tid);
>         select(sockfd + 1, &fds, NULL, NULL, &tv);
>     }

That's not allowed.  What is the select call waiting for?  You
didn't bind or connect it.

Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Developer                                mailto:cygwin AT cygwin DOT com
Red Hat, Inc.

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