[tahoe-lafs-trac-stream] [tahoe-lafs] #1274: eliminate pywin32 dependency

[tahoe-lafs]

#1274: eliminate pywin32 dependency
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     Reporter:  davidsarah    |       Owner:  warner                                       
         Type:  defect        |      Status:  new                                          
     Priority:  major         |   Milestone:  1.8.2                                        
    Component:  code-storage  |     Version:  1.8.0                                        
   Resolution:                |    Keywords:  pywin32 windows win64 docs-needed news-needed
Launchpad Bug:                |  
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Comment (by warner):

 Replying to [comment:14 davidsarah]:
 >
 > * change {{{test_runner.py}}} and {{{iputil.py}}} to use the
 >   {{{subprocess}}} module.

 The usual problem with using {{{subprocess}}} is {{{SIGCHLD}}}: Twisted's
 reactor and {{{subprocess.py}}} fight over who gets to register a handler.
 The reactor isn't strictly running during a {{{trial}}} unit test context.
 It
 sort of is, but {{{reactor.run()}}} isn't called, and I've had problems
 using
 {{{reactor.spawnProcess}}} or {{{utils.getProcessOutputAndValue}}} from
 tests
 (the "potential zombie child" warning), which I've addressed by explicitly
 invoking the twisted call that installs its SIGCHLD handler.

 But it almost certainly is running when {{{iputil.py}}} gets used. So if
 {{{subprocess.py}}} takes over the SIGCHLD handler, we need to look
 carefully
 and make sure that Twisted gets it back again afterwards. I don't know if
 we
 use {{{getProcessOutputAndValue}}} anywhere outside of {{{iputil.py}}}, so
 a
 problem there may not bite us until we add a call like that later (like
 maybe
 a call to {{{du -s}}} to measure storage usage), and I'd like to avoid
 that
 uncertainty.

 So maybe a quick manual test which does a {{{reactor.spawnProcess}}} in
 response to a WUI button press is in order.

-- 
Ticket URL: <http://tahoe-lafs.org/trac/tahoe-lafs/ticket/1274#comment:20>
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