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Date: | Tue, 21 Jul 2009 07:04:09 -0600 |
From: | Eric Blake <ebb9 AT byu DOT net> |
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To: | cygwin AT cygwin DOT com, newlib AT sources DOT redhat DOT com |
Subject: | close on exec atomics |
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 It seems like it would be pretty easy to add several new close-on-exec features required by POSIX 2008: open(name, O_RDONLY | O_CLOEXEC); // skips the need to use fcntl fcntl(fd, F_DUPFD_CLOEXEC); // like F_DUPFD, but closes window without having to use // fcntl(fd, F_SETFD, fcntl(fd, F_GETFD)) and those provided by glibc as extensions: fopen(name, "re"); // like fopen "r", but with cloexec set The argument is that in multi-threaded apps, if one thread opens a file but has not yet turned on the close-on-exec bit while another thread does a fork-and-exec, then you leaked the fd into the child; and these new flags close the window. Should I go ahead and prepare a patch for the newlib side? - -- Don't work too hard, make some time for fun as well! Eric Blake ebb9 AT byu DOT net -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkplvMkACgkQ84KuGfSFAYD+1ACfRInQJqHLu2v79zNU+1876TWv an8AoLKXGav0FWdsPiauLd0d11rCfTtt =KZci -----END PGP SIGNATURE----- -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
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