Files
pyDevSup/python/devsup/util.py
Michael Davidsaver c9820d264f support python 3.2
2013-04-07 08:40:00 -04:00

145 lines
3.5 KiB
Python

from __future__ import print_function
import threading, traceback
class StoppableThread(threading.Thread):
"""A thread which can be requested to stop.
The thread run() method should periodically call the shouldRun()
method and return if this yields False.
>>> class TestThread(StoppableThread):
... def __init__(self):
... super(TestThread,self).__init__()
... self.E=threading.Event()
... def run(self):
... import time
... self.cur = threading.current_thread()
... self.E.set()
... while self.shouldRun():
... time.sleep(0.01)
>>> T = TestThread()
>>> T.start()
>>> T.E.wait()
True
>>> T.cur is T
True
>>> T.join()
>>> T.is_alive()
False
"""
def __init__(self, max=0):
super(StoppableThread, self).__init__()
self.__stop = True
self.__lock = threading.Lock()
def start(self):
with self.__lock:
self.__stop = False
super(StoppableThread, self).start()
def join(self):
with self.__lock:
self.__stop = True
super(StoppableThread, self).join()
def shouldRun(self):
with self.__lock:
return not self.__stop
class Worker(threading.Thread):
"""A threaded work queue.
>>> w = Worker()
>>> w = Worker()
>>> w.start()
>>> w.join()
>>> import threading
>>> E = threading.Event()
>>> w = Worker()
>>> w.start()
>>> w.add(E.set)
>>> E.wait(1.0)
True
>>> w.join()
"""
def __init__(self, max=0):
super(Worker, self).__init__()
self.__stop = None
self.__lock = threading.Lock()
self.__update = threading.Condition(self.__lock)
self.maxQ, self._Q = max, []
def join(self, flush=True):
self.__update.acquire()
try:
if self.__stop is not None:
raise RuntimeError("Someone else is already trying to stop me")
self.__stop = threading.Event()
self.__update.notify()
self.__update.release()
try:
self.__stop.wait()
finally:
self.__update.acquire()
self.__stop = None
if flush:
self._Q = []
finally:
self.__update.release()
def __len__(self):
with self.__lock:
return len(self._Q)
def add(self, func, args=(), kws={}):
with self.__lock:
if self.__stop is not None:
return
elif self.maxQ>0 and len(self._Q)>=self.maxQ:
raise RuntimeError('Worker queue full')
self._Q.append((func,args,kws))
self.__update.notify()
def run(self):
self.__update.acquire()
try:
while True:
while self.__stop is None and len(self._Q)==0:
self.__update.wait()
if self.__stop is not None:
break
F, A, K = self._Q.pop(0)
self.__update.release()
try:
F(*A,**K)
except:
print('Error running',F,A,K)
traceback.print_exc()
finally:
self.__update.acquire()
self.__stop.set()
except:
traceback.print_exc()
finally:
self.__update.release()
if __name__=='__main__':
import doctest
doctest.testmod()