Title: Popen3 might cause dead lock
Type: enhancement Stage:
Components: Documentation Versions:
Status: closed Resolution: fixed
Dependencies: Superseder:
Assigned To: fdrake Nosy List: fdrake, guettli
Priority: normal Keywords:

Created on 2002-03-16 09:49 by guettli, last changed 2002-06-18 20:41 by guettli. This issue is now closed.

Messages (3)
msg9740 - (view) Author: Thomas Guettler (guettli) Date: 2002-03-16 09:49
Please include a hint in the documentation of popen3
that it can produce a dead lock.


The subprocess writes a lot of data to stderr and
blocks and your application reads from stdout. It
might result in a dead lock

An other explanation to this can be found here:

Unfortunately popen3 is documented twice. Would be nice
if there is a
hint to deadlocks at both places. I am programming
quite long and I
lost hours debugging why this happens sometimes and
sometimes not. (It
only happens if you have a lot of output)

In the documentation of Perl there is a hint
to this problem, too.


(I already submitted this feature request to But received no response)

msg9741 - (view) Author: Fred Drake (fdrake) (Python committer) Date: 2002-06-18 20:32
Logged In: YES 

Added a section on flow control issues to the documentation
for the popen2 module, with a reference from the
corresponding functions in the os module.

Doc/lib/libos.tex:     1.90,,
Doc/lib/libpopen2.tex: 1.16,,
msg9742 - (view) Author: Thomas Guettler (guettli) Date: 2002-06-18 20:41
Logged In: YES 

Thank you very much!
Date User Action Args
2002-03-16 09:49:28guettlicreate