Close stdout socket on CGI after fork with subprocess

[Kushal Kumaran]

On Mon, Jan 10, 2011 at 1:15 PM, Thibaud Roussillat
<thibaud.roussillat at gmail.com> wrote:
> On Sat, Jan 8, 2011 at 3:19 AM, Kushal Kumaran
> <kushal.kumaran+python at gmail.com> wrote:
>>
>> On Fri, Jan 7, 2011 at 8:08 PM, Thibaud Roussillat
>> <thibaud.roussillat at gmail.com> wrote:
>> > Hi,
>> >
>> > I work with Python 2.4 and CGI.
>> >
>> > I have a CGI which call a Python script in background process and return
>> > result before background task is finished.
>> >
>> > Actually, the browser displays response but it is waiting for end of
>> > background task because the socket is not closed.
>> >
>> > Internet told me that I must close the stdout file descriptor
>> > (sys.stdout.close()) to close the socket but it doesn't work.
>> >
>> > The background task is launched via subprocess.Popen and is attached to
>> > the
>> > root process on ps command.
>> >
>>
>> This means that the parent process finished before the child.  Call
>> wait() on the Popen object to wait for the child to terminate.
>> Depending on how you create the Popen object, the child process may
>> inherit your own stdout.  In that case, the child process may be
>> keeping the socket open after the parent dies.
>>
>
> <top-posting corrected>
>
> In fact, the parent process finished before the child, it's why I want to
> run the child in a forked process, and close the socket of the parent task.
>
> The goal is not to wait for the child process but to leave it lead one's own
> life as a background task. The client don't have to wait for the end of the
> child process.
>
> Is there a way to not inherit from the parent stdout on the child process ?
>

open os.devnull and pass that file object as stdin, stdout and stderr
for the child process.  Hopefully the program you are running has been
designed not to expect to be able to use stdin/stdout/stderr.

Please keep the discussion on the mailing list.  Other people on the
list are smarter than me.  Also, the convention on this mailing list
is to keep replies below the quoted content.

-- 
regards,
kushal