By using this site, you agree to our updated Privacy Policy and our Terms of Use. Manage your Cookies Settings.
443,813 Members | 1,121 Online
Bytes IT Community
+ Ask a Question
Need help? Post your question and get tips & solutions from a community of 443,813 IT Pros & Developers. It's quick & easy.

Orphaned child processes

P: n/a
I'm using the Python processing module. I've just run into a problem
though. Actually, it's a more general problem that isn't specific to
this module, but to the handling of Unix (Linux processes) in general.
Suppose for instance that for some reason or another, after forking
several child processes, the main process terminates or gets killed
(or segfaults or whatever) and the child processes are orphaned. Is
there any way to automatically arrange things so that they auto-
terminate or, in other words, is there a way to make the child
processes terminate when the parent terminates?

Thank you.
Apr 7 '08 #1
Share this Question
Share on Google+
2 Replies


P: n/a
ro*********@gmail.com wrote:
I'm using the Python processing module. I've just run into a problem
though. Actually, it's a more general problem that isn't specific to
this module, but to the handling of Unix (Linux processes) in general.
Suppose for instance that for some reason or another, after forking
several child processes, the main process terminates or gets killed
(or segfaults or whatever) and the child processes are orphaned. Is
there any way to automatically arrange things so that they auto-
terminate or, in other words, is there a way to make the child
processes terminate when the parent terminates?

Thank you.
Put a thread in the child which reads stdin, and make stdin
connect to a pipe from the parent. When the parent terminates,
the child will get a SIGPIPE error and raise an exception.

John Nagle
Apr 7 '08 #2

P: n/a
In article <47***********************@news.sonic.net>,
John Nagle <na***@animats.comwrote:
ro*********@gmail.com wrote:
I'm using the Python processing module. I've just run into a problem
though. Actually, it's a more general problem that isn't specific to
this module, but to the handling of Unix (Linux processes) in general.
Suppose for instance that for some reason or another, after forking
several child processes, the main process terminates or gets killed
(or segfaults or whatever) and the child processes are orphaned. Is
there any way to automatically arrange things so that they auto-
terminate or, in other words, is there a way to make the child
processes terminate when the parent terminates?

Thank you.

Put a thread in the child which reads stdin, and make stdin
connect to a pipe from the parent. When the parent terminates,
the child will get a SIGPIPE error and raise an exception.

John Nagle
That could work, but not precisely in that manner. You get
SIGPIPE when you write to a closed pipe. When you read from one,
you get end of file, i.e., a normal return with 0 bytes.

When you test it, make sure to try a configuration with more
than one child process. Since the parent holds the write end
of the pipe, subsequently forked child processes could easily
inherit it, and they'll hold it open and spoil the effect.

Donn Cave, do**@u.washington.edu
Apr 7 '08 #3

This discussion thread is closed

Replies have been disabled for this discussion.