Method Name:
is_alive()
Method Overview:
is_alive() method checks whether a thread is alive and returns a boolean value based on the thread status. is_alive() method is often used in thread synchronisation so as to check whether a thread is alive before sending any signals to it. However efforts need to be taken to have status of the latest thread status from a most recent call to is_alive().
Return value:
True - When a thread is alive
False - When a thread has been already terminated completely
Example:
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from threading import Thread; from threading import Event; import time;
class ChildThread(Thread): myStopSignal = 0
def __init__(self,aStopSignal): Thread.__init__(self) self.myStopSignal = aStopSignal
def run(self): print("Child Thread:Started") for i in range(1,10): if(self.myStopSignal.wait(0)): print ("ChildThread:Asked to stop") break;
print("Doing some low priority task taking long time") time.sleep(2) #Just simulating time taken by task with sleep
print("Child Thread:Exiting")
print("Main Thread:Started") aStopSignal = Event() aChildThread = ChildThread(aStopSignal) aChildThread.start() aChildThread.join(4) # I can wait for 4 seconds only
if aChildThread.is_alive() is True: aStopSignal.set() aChildThread.join()
print("Main Thread; Exiting") |
Output:
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Main Thread:Started Child Thread:Started Doing some low priority task taking long time Doing some low priority task taking long time ChildThread:Asked to stop Child Thread:Exiting Main Thread; Exiting |