"""Windows service. Requires pywin32."""
import os
import win32api
import win32con
import win32event
import win32service
import win32serviceutil
from cherrypy.process import wspbus, plugins
[docs]class ConsoleCtrlHandler(plugins.SimplePlugin):
"""A WSPBus plugin for handling Win32 console events (like Ctrl-C)."""
def __init__(self, bus):
self.is_set = False
plugins.SimplePlugin.__init__(self, bus)
[docs] def start(self):
if self.is_set:
self.bus.log('Handler for console events already set.', level=40)
return
result = win32api.SetConsoleCtrlHandler(self.handle, 1)
if result == 0:
self.bus.log('Could not SetConsoleCtrlHandler (error %r)' %
win32api.GetLastError(), level=40)
else:
self.bus.log('Set handler for console events.', level=40)
self.is_set = True
[docs] def stop(self):
if not self.is_set:
self.bus.log('Handler for console events already off.', level=40)
return
try:
result = win32api.SetConsoleCtrlHandler(self.handle, 0)
except ValueError:
# "ValueError: The object has not been registered"
result = 1
if result == 0:
self.bus.log('Could not remove SetConsoleCtrlHandler (error %r)' %
win32api.GetLastError(), level=40)
else:
self.bus.log('Removed handler for console events.', level=40)
self.is_set = False
[docs] def handle(self, event):
"""Handle console control events (like Ctrl-C)."""
if event in (win32con.CTRL_C_EVENT, win32con.CTRL_LOGOFF_EVENT,
win32con.CTRL_BREAK_EVENT, win32con.CTRL_SHUTDOWN_EVENT,
win32con.CTRL_CLOSE_EVENT):
self.bus.log('Console event %s: shutting down bus' % event)
# Remove self immediately so repeated Ctrl-C doesn't re-call it.
try:
self.stop()
except ValueError:
pass
self.bus.exit()
# 'First to return True stops the calls'
return 1
return 0
[docs]class Win32Bus(wspbus.Bus):
"""A Web Site Process Bus implementation for Win32.
Instead of time.sleep, this bus blocks using native win32event objects.
"""
def __init__(self):
self.events = {}
wspbus.Bus.__init__(self)
def _get_state_event(self, state):
"""Return a win32event for the given state (creating it if needed)."""
try:
return self.events[state]
except KeyError:
event = win32event.CreateEvent(None, 0, 0,
'WSPBus %s Event (pid=%r)' %
(state.name, os.getpid()))
self.events[state] = event
return event
def _get_state(self):
return self._state
def _set_state(self, value):
self._state = value
event = self._get_state_event(value)
win32event.PulseEvent(event)
state = property(_get_state, _set_state)
[docs] def wait(self, state, interval=0.1, channel=None):
"""Wait for the given state(s), KeyboardInterrupt or SystemExit.
Since this class uses native win32event objects, the interval
argument is ignored.
"""
if isinstance(state, (tuple, list)):
# Don't wait for an event that beat us to the punch ;)
if self.state not in state:
events = tuple([self._get_state_event(s) for s in state])
win32event.WaitForMultipleObjects(
events, 0, win32event.INFINITE)
else:
# Don't wait for an event that beat us to the punch ;)
if self.state != state:
event = self._get_state_event(state)
win32event.WaitForSingleObject(event, win32event.INFINITE)
class _ControlCodes(dict):
"""Control codes used to "signal" a service via ControlService.
User-defined control codes are in the range 128-255. We generally use
the standard Python value for the Linux signal and add 128. Example:
>>> signal.SIGUSR1
10
control_codes['graceful'] = 128 + 10
"""
def key_for(self, obj):
"""For the given value, return its corresponding key."""
for key, val in self.items():
if val is obj:
return key
raise ValueError('The given object could not be found: %r' % obj)
control_codes = _ControlCodes({'graceful': 138})
[docs]def signal_child(service, command):
if command == 'stop':
win32serviceutil.StopService(service)
elif command == 'restart':
win32serviceutil.RestartService(service)
else:
win32serviceutil.ControlService(service, control_codes[command])
class PyWebService(win32serviceutil.ServiceFramework):
"""Python Web Service."""
_svc_name_ = 'Python Web Service'
_svc_display_name_ = 'Python Web Service'
_svc_deps_ = None # sequence of service names on which this depends
_exe_name_ = 'pywebsvc'
_exe_args_ = None # Default to no arguments
# Only exists on Windows 2000 or later, ignored on windows NT
_svc_description_ = 'Python Web Service'
def SvcDoRun(self):
from cherrypy import process
process.bus.start()
process.bus.block()
def SvcStop(self):
from cherrypy import process
self.ReportServiceStatus(win32service.SERVICE_STOP_PENDING)
process.bus.exit()
def SvcOther(self, control):
process.bus.publish(control_codes.key_for(control))
if __name__ == '__main__':
win32serviceutil.HandleCommandLine(PyWebService)