So far, I've just killed the process after timeout, which is fine if there are no childprocesses in there.
Now, we've shifted to the Nose module for running our unit-tests (and Freshen for the specification-by-example acceptance tests), and that always uses one or more subprocesses to execute tests in... ergo: problems.
The simplest way is just to run taskkill, which is available at least from Windows XP...
p = subprocess.POpen(....)
# wait for exit or timeout
if timeout:
subprocess.call(['taskkill', '/F', '/T', '/PID', str(p.pid)])
If you don't want to run another program, there's the long way around, by using comtypes and ctypes to access the WMI and Win32 API functions. I wrote this before I found out about the above, but it was easy to port C++ samples to this, and I already had comtypes in our system. Maybe it's useful for someone...
def killsubprocesses(parent_pid):
'''kill parent and all subprocess using COM/WMI and the win32api'''
log = logging.getLogger('killprocesses')
try:
import comtypes.client
except ImportError:
log.debug("comtypes not present, not killing subprocesses")
return
logging.getLogger('comtypes').setLevel(logging.INFO)
log.debug('Querying process tree...')
# get pid and subprocess pids for all alive processes
WMI = comtypes.client.CoGetObject('winmgmts:')
processes = WMI.InstancesOf('Win32_Process')
subprocess_pids = {} # parent pid -> list of child pids
for process in processes:
pid = process.Properties_('ProcessID').Value
parent = process.Properties_('ParentProcessId').Value
log.trace("process %i's parent is: %s" % (pid, parent))
subprocess_pids.setdefault(parent, []).append(pid)
subprocess_pids.setdefault(pid, [])
# find which we need to kill
log.debug('Determining subprocesses for pid %i...' % parent_pid)
processes_to_kill = []
parent_processes = [parent_pid]
while parent_processes:
current_pid = parent_processes.pop()
subps = subprocess_pids[current_pid]
log.debug("process %i children are: %s" % (current_pid, subps))
parent_processes.extend(subps)
processes_to_kill.extend(subps)
# kill the subprocess tree
if processes_to_kill:
log.info('Process pid %i spawned %i subprocesses, terminating them...' %
(parent_pid, len(processes_to_kill)))
else:
log.debug('Process pid %i had no subprocesses.' % parent_pid)
import ctypes
kernel32 = ctypes.windll.kernel32
for pid in processes_to_kill:
hProcess = kernel32.OpenProcess(PROCESS_TERMINATE, FALSE, pid);
if not hProcess:
_log.warning('Unable to open process pid %i for termination' % pid)
else:
_log.debug('Terminating pid %i' % pid)
kernel32.TerminateProcess(hProcess, 3)
kernel32.CloseHandle(hProcess)
This code could of course be improved by not walking all processes, OTOH, I have between 80 and 200 running on my PC at all times, so it's not a lot of data. Especially, since I only call this function if I've already waited too long, it doesn't matter if it takes a few more seconds.
Also, I long for Haskell where this tree-walking mapping stuff could be way more concise. Maybe python's itertools package has something I could use to avoid coding the dirty stuff by hand.
A few more solutions is available at this StackOverflow question, depending on what kind third-party of libraries you have available.
A few more solutions is available at this StackOverflow question, depending on what kind third-party of libraries you have available.
Moral of the story:
It doesn't matter if you have to write a lot of code in order to find out that there's a one liner which solves your problem. Use the short version and be happy you don't have to maintain the 30+ lines version. :)
