win32 service and time.sleep()
Laszlo Zsolt Nagy
gandalf at designaproduct.biz
Tue Sep 20 11:07:08 EDT 2005
rbt wrote:
>I have a win32 service written in Python. It works well. It sends a
>report of the status of the machine via email periodically. The one
>problem I have is this... while trying to send an email, the script
>loops until a send happens and then it breaks. Should it be unable to
>send, it sleeps for 10 minutes with time.sleep(600) and then wakes and
>tries again. This is when the problem occurs. I can't stop the service
>while the program is sleeping. When I try, it just hangs until a reboot.
>Can some suggest how to fix this?
>
>
Yes. Generally, most of the win32 services work like this:
- the main thread listens to win32 service commands
- when starting the service, you should create a new worker thread that
does the job for you
- when stopping the service, your service should report
win32service.SERVICE_STOP_PENDING immediately, and ask the worker thread
to terminate
- you should be continuously reporting win32service.SERVICE_STOP_PENDING
until your workder thread has stopped
Here is a simple module that uses a 'Processor' class and a new thread
to do the work.
(The full program is here: http://mess.hu/download/SimpleHTTPService.zip )
class Service(win32serviceutil.ServiceFramework):
_svc_name_ = SERVICE_NAME
_svc_display_name_ = SERVICE_DISPLAY
def __init__(self, args):
win32serviceutil.ServiceFramework.__init__(self, args)
self.stopped = threading.Event()
self.stopped.clear()
self.logger = getLogger(SERVICE_NAME)
def SvcStop(self):
self.logger.info("Got SvcStop, trying to stop service...")
self.ReportServiceStatus(win32service.SERVICE_STOP_PENDING)
self.stopped.set()
def SvcDoRun(self):
"""Write an event log record - in debug mode we will also see
this message printed."""
try:
import servicemanager
servicemanager.LogMsg(
servicemanager.EVENTLOG_INFORMATION_TYPE,
servicemanager.PYS_SERVICE_STARTED,
(self._svc_name_, '')
)
self.logger.info("Started.")
self.logger.debug("Creating processor instance")
processor = Processor(self.stopped)
self.logger.debug("Starting processor thread")
thread.start_new_thread(processor.Process,())
self.logger.debug("Waiting for the processor thread to finish")
self.stopped.wait()
self.logger.debug("Stopping")
time.sleep(1)
while not processor.stopped.isSet():
self.ReportServiceStatus(win32service.SERVICE_STOP_PENDING, 5000)
time.sleep(5)
servicemanager.LogMsg(
servicemanager.EVENTLOG_INFORMATION_TYPE,
servicemanager.PYS_SERVICE_STOPPED,
(self._svc_name_, "")
)
self.logger.info("Stopped")
except:
self.logger.error('',exc_info = sys.exc_info())
if __name__=='__main__':
win32serviceutil.HandleCommandLine(Service)
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