Re: [pygame] run_tests.py subprocess mode and Build Page extensions

[Lenard Lindstrom <len-l@xxxxxxxxx>]

If you are asking if there are situations where the kill function will 
fail, the only one I can think of is if it is given an invalid pid. For 
the unit tests I cannot see access rights becoming an issue as these are 
child processes. Even terminating a process that has already quit 
doesn't raise an exception.

>>> import win32api as w
>>> import subprocess as sp
>>> o = open('stdout.txt', 'w')
>>> s =  sp.Popen('''python -c "print 'Hello.'"''', stdout=o)
>>> s.wait()
0
>>> s.pid
-468795
>>> print open('stdout.txt').read()
Hello.

>>> h = w.OpenProcess(1, 0, s.pid)
>>> w.TerminateProcess(h, 0)
>>> w.TerminateProcess(h, 0)
>>> w.CloseHandle(h)
>>> w.TerminateProcess(h, 0)
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
pywintypes.error: (6, 'TerminateProcess', 'The handle is invalid.')


Is is probably pointless to try and kill a process more than once on 
Windows. In this case it is best to let any exceptions in kill() 
propagate. It would indicate a bug in the program. But I cannot speak 
for Unix.

As for this possible kill code:

       def kill(self):
           ......
               # This works as well
               # win32api.TerminateProcess(int(self._handle), 0)
                                          # handle,  # exit code

Using the undocumented _handle attribute should be fine in this case 
because it is accessed within a subclass and in the unlikely case it 
goes the code can be easily changed. Interestingly Python 2.6 introduces 
the Popen terminate method as well as a Unix only kill method. Neither 
has a return value.

Lenard


Nicholas Dudfield wrote:
> Lenard,
>
> I will commit your change, thanks.
>
> I must admit I took that recipe and used it without knowing exactly 
> how it worked much the same way I would use a library.
>
> How does the async Popen recipe look to you?  I'm starting to wonder 
> at the wisdom of using recipes. That was from ActiveState Python 
> CookBook.
>
> I put in one test for it but......
>
> if ret_code is None:
>    proc.kill()
>
> Should we make it try a few times upon failure? If it fails would 
> there be much chance of killing it in the immediate future? What 
> situations would cause a failure?
>
> It might even make sense to move that kill functionality into the 
> async_sub.Popen method read_async().
>
> read_async(time_out=10, kill=True)
>
> Ciao.
> > I tried the updated run_tests and it works. Killed python 
> > interpreters disappear. Thanks for the changes.
> >
> > I do suggest some modifications to Popen.kill though. First, the 
> > win32api functions raise Python exceptions on Windows errors rather 
> > than use return values. Second, handles should be closed. Here is my 
> > version:
> >
> >        def kill(self):
> >            """kill function for Win32"""
> >            try:
> >                handle = win32api.OpenProcess(1, 0, self.pid)
> >                try:
> >                    win32api.TerminateProcess(handle, 0)
> >                finally:
> >                    win32api.CloseHandle(handle)
> >            except win32api.error:
> >                return False
> >            return True