Thread that I can pause and resume?
Condition
s can be used for this.
Here's an example filling in your skeleton:
class Me(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
#flag to pause thread
self.paused = False
# Explicitly using Lock over RLock since the use of self.paused
# break reentrancy anyway, and I believe using Lock could allow
# one thread to pause the worker, while another resumes; haven't
# checked if Condition imposes additional limitations that would
# prevent that. In Python 2, use of Lock instead of RLock also
# boosts performance.
self.pause_cond = threading.Condition(threading.Lock())
def run(self):
while True:
with self.pause_cond:
while self.paused:
self.pause_cond.wait()
#thread should do the thing if
#not paused
print 'do the thing'
time.sleep(5)
def pause(self):
self.paused = True
# If in sleep, we acquire immediately, otherwise we wait for thread
# to release condition. In race, worker will still see self.paused
# and begin waiting until it's set back to False
self.pause_cond.acquire()
#should just resume the thread
def resume(self):
self.paused = False
# Notify so thread will wake after lock released
self.pause_cond.notify()
# Now release the lock
self.pause_cond.release()
Hope that helps.
Use threading.Event
instead of a boolean variable, and add another event for busy state:
def __init__(self):
...
self.can_run = threading.Event()
self.thing_done = threading.Event()
self.thing_done.set()
self.can_run.set()
def run(self):
while True:
self.can_run.wait()
try:
self.thing_done.clear()
print 'do the thing'
finally:
self.thing_done.set()
def pause(self):
self.can_run.clear()
self.thing_done.wait()
def resume(self):
self.can_run.set()
edit: previous answer was wrong, I fixed it and changed variable names to be clear