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Message-ID:	<077d01c1400e$2d92cdc0$d2823bd5@dmitry>
From:	"Dmitry Timoshkov" <dmitry AT baikal DOT ru>
To:	<cygwin AT cygwin DOT com>
Subject:	fcntl(F_SETFD) on a file or socket handle
Date:	Tue, 18 Sep 2001 15:48:22 +0900
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Hello.

Just want report a serious bug in Cygwin.

Many applications use this construct in their code:
fcntl(fd, F_SETFD, 1); /* set close on exec flag */

fcntl(fd) below is a replacement for the above construct,
fd - file/socket descriptor, resulted from an open() or a socket() call.

Some symptoms:

1. If an fd is a socket and fcntl(fd) is called right after the connect(fd) call,
connection will get broken.

2. If an fd is transferred via a pipe end and fcntl(fd) is called right after
write(pipe, &fd, sizeof(fd)) call, the another pipe end will receive an invalid
fd handle.

If in the both cases above add sleep(1) before fcntl(fd), then all works without
a failure.

I didn't investigate it further, and probably will not have time in the near
future to do so. Sorry.

--
Dmitry.


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