On Mon, Aug 19, 2002 at 01:43:52AM -0300, Cristiano Lincoln Mattos wrote:
>
> This works OK in linux, but under Cygwin, the the connection
> filehandle/socket and the filehandles that are used to execute the
> external program are somehow linked... the connection is only
> terminated after the program ends. In the test case below, the
> program to be executed is just "/bin/ls; sleep 10; /bin/ls".
> Under cygwin, the socket stays alive until all the execution is
> finished. Under linux, everything works OK, with the connection
> being close, and the execution happenning independently.
> Am i doing something wrong with the handles, or is this a
> cygwin bug ? Any help appreciated.
We discussed this on EFnet's #poe channel for a while, but nothing
came of it. One of the solutions we tried was to close file
descriptors 3 and up in the child process. That may not be enough.
I just received a similar problem report and suggested a solution that
might also work for you. Namely, sockets should have their
close-on-exec flags set to true so they don't "bleed" into child
processes.
If this sample code works for you, I'd like to consider setting the
close-on-exec for sockets in SocketFactory. Please let me know.
-- Rocco Caputo / [EMAIL PROTECTED] / poe.perl.org / poe.sf.net
Forwarded message:
| On Sat, Aug 31, 2002 at 05:25:10PM -0400, Steven Chau wrote:
| >
| > I'm trying to write a server which accepts incoming request. The
| > request can be as simple as testing whether a process exists or starting
| > up a server related process using POE::Wheel:Run to fork it off. The
| > problem I'm having is that the forked child process will inherit all
| > parent file descriptors resulting in lingering socket (SocketFactory)
| > file handles upon close of Wheel::Run. Is there way I can gracefully
| > remove all inherited file descriptors before launching Wheel::Run?
|
| Good morning! This is an interesting problem. Which operating system
| and Perl version are you using?
|
| It is possible to set the close-on-exec flag for file descriptors
| other than 0, 1, or 2. That will cause them to be closed when the
| program is executed in the child process.
|
| I'm leery of touching the close-on-exec flag for file descriptors
| since the framework doesn't know what you intend to do with them.
|
| Here's some untested sample code:
|
| use POSIX qw(fcntl_h);
| use Symbol qw(gensym);
| for my $fd (3..255) {
| my $handle = gensym;
| if (open $handle, "<&=$fd") {
| my $flag = fcntl($handle, F_GETFD, 0);
| if (defined $flag) {
| $flag = 1;
| fcntl($handle, F_SETFD, $flag);
| }
| }
| }
|
| I have a feeling that I can safely do this to sockets created with
| SocketFactory. I'll run it past POE's mailing list to be sure.
|
| -- Rocco Caputo / [EMAIL PROTECTED] / poe.perl.org / poe.sf.net
