[Python-Dev] About SSL tests

[Trent Mick]

Christian Heimes wrote:
>> I'd be willing to look at adding it, if the group thinks it's the right 
>> thing to do.
> 
> I like the idea and I'm proposing to add two more methods to subprocess
> Popen.
> 
> class Popen(...):
>     ...
>     def signal(self, signal):
>         """Send a signal to the process (UNIX only)
> 
>         signal is constant from the signal module
>         """
> 
>     def terminate(self, force=False):
>         """Terminate the process
> 
>         On UNIX terminate(False) is equivalent to signal(SIGTERM) and
>         terminate(True) to signal(SIGKILL).
> 
>         On Windows ... (does Windows support a forced terminate?)
>         """

Here is what my process.py [1] does for termination (not suggesting you 
follow the API here, just showing how it handles termination on 
Windows). Some of the Windows logic is borrowed from PyWin32's 
winprocess.py [2]


>     def kill(self, exitCode=0, gracePeriod=1.0, sig=None):
>         """Kill process.
>         
>         "exitCode" [deprecated, not supported] (Windows only) is the
>             code the terminated process should exit with.
>         "gracePeriod" (Windows only) is a number of seconds the process is
>             allowed to shutdown with a WM_CLOSE signal before a hard
>             terminate is called.
>         "sig" (Unix only) is the signal to use to kill the process. Defaults
>             to signal.SIGKILL. See os.kill() for more information.
> 
>         Windows:
>             Try for an orderly shutdown via WM_CLOSE.  If still running
>             after gracePeriod (1 sec. default), terminate.
>         """
>         if sys.platform.startswith("win"):
>             import win32gui
>             # Send WM_CLOSE to windows in this process group.
>             win32gui.EnumWindows(self._close_, 0)
> 
>             # Send Ctrl-Break signal to all processes attached to this
>             # console. This is supposed to trigger shutdown handlers in
>             # each of the processes.
>             try:
>                 win32api.GenerateConsoleCtrlEvent(CTRL_BREAK_EVENT,
>                                                   self._processId)
>             except AttributeError:
>                 log.warn("The win32api module does not have "\
>                          "GenerateConsoleCtrlEvent(). This may mean that "\
>                          "parts of this process group have NOT been killed.")
>             except win32api.error, ex:
>                 if ex.args[0] not in (6, 87):
>                     # Ignore the following:
>                     #   api_error: (87, 'GenerateConsoleCtrlEvent', 'The parameter is incorrect.')
>                     #   api_error: (6, 'GenerateConsoleCtrlEvent', 'The handle is invalid.')
>                     # Get error 6 if there is no console.
>                     raise
>             
>             # Last resort: call TerminateProcess if it has not yet.
>             retval = 0
>             try:
>                 self.wait(gracePeriod)
>             except ProcessError, ex:
>                 log.info("[%s] Process.kill: calling TerminateProcess", id(self))
>                 win32process.TerminateProcess(self._hProcess, -1)
>                 win32api.Sleep(100) # wait for resources to be released
> 
>         else:
>             if sig is None:
>                 sig = signal.SIGKILL
>             try:
>                 os.kill(self._pid, sig)
>             except OSError, ex:
>                 if ex.errno != 3:
>                     # Ignore:   OSError: [Errno 3] No such process
>                     raise


Links:
[1] http://trentm.com/projects/process/
[2] 
http://pywin32.cvs.sourceforge.net/pywin32/pywin32/win32/Demos/winprocess.py?revision=1.2&view=markup#l_121


-- 
Trent Mick
trentm at activestate.com