On Wed, Jul 29, 2009 at 02:20:32PM +0200, Bram Moolenaar wrote: > > James - > > > > On Sat, Oct 07, 2006 at 03:32:45PM +0200, Bram Moolenaar wrote: > > > > > > ugh, cough, that's a dusty email! > > > > I finally had a chance to look into this and find how we could avoid it. > > :) > > > > > On Sat, Oct 07, 2006 at 03:32:45PM +0200, Bram Moolenaar wrote: > > > > > Hmm, perhaps the problem is that system() or execvp() doesn't close > > > > > the > > > > > file descriptors in a child process? > > > > > > > > Indeed, that is the case. Children inherit their parent's file > > > > descriptors unless the file descriptors are set to close on exec(). > > > > Attached patch does that. > > > > > > I don't think the FD_CLOEXEC flag is always available. I'm not sure > > > when it was added. Adding an autoconf check for it will help to avoid > > > breaking the build on old systems. > > > > I don't know autoconf, so I'm afraid I wouldn't be able to provide this > > part of the patch any time soon. FD_CLOEXEC is required by POSIX > > though, so I'm unsure how much this check is really needed. > > > > > This page mentions that one should get the flags first: > > > http://www.cs.ui.ac.id/WebKuliah/IKI10100/resources/contest/OnlineJudge/gnudoc/libc/Descriptor_Flags.html > > > > Ah, yes. Currently FD_CLOEXEC is the only supported flag, but that > > would be the proper way to do this for long-term robustness. Should I > > update this part of the patch or will you take care of it with the > > autoconf checks? > > I would appreciate it if you can update the patch as far as you can and > test it. Then I'll have a look at it as well. It's always better to > have more than one person look at these things to avoid mistakes.
Updated patch attached. The flags are retrieved first and F_SETFD is only called if that was successful and FD_CLOEXEC isn't already set. I've also added an autoconf check which defines HAVE_FD_CLOEXEC if it is successful. That is also used to guard the related code instead of the previous "#ifdef UNIX". I followed the model of similar autoconf checks for the FD_CLOEXEC check. I think it should be sufficient but I don't have any systems which have fcntl.h yet don't define FD_CLOEXEC. -- James GPG Key: 1024D/61326D40 2003-09-02 James Vega <[email protected]>
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