CODEWITHSUNDEEP
pythonmultithreading
Gооd_Mаn
Gооd_Mаn

Reputation: 1088

Multi-threading condition, start thread on the second iteration?

[Challenge]:

I have two threads, the first one is some_signal and the second one is post_proccesing.

For the first iteration, I would like to run, post_proccesing after some_signal.

And after the first iteration. I would like to start post_proccesing thread, so post_proccesing would use some_signal data from the previous loop.

[Pseudocode]:

[My Attempt]:

I have tried to implement it using the following way, but I'm not entirely sure,if I've done it correctly:

import threading

def some_signal():
    print threading.currentThread().getName(), 'Get signal'

def post_proccesing():
    print threading.currentThread().getName(), 'Process the signa;'

t = threading.Thread(name='post_proccesing', target=post_proccesing)
w = threading.Thread(name='some_signal', target=some_signal)

flag = 0;
for i in range(5):
    t = threading.Thread(target=some_signal) # use default name

    if flag == 0:
        some_signal() # use default name
        flag  = flag + 1;
    else:
        w = threading.Thread(target=post_proccesing) # use default name
    w.start()
    t.start()

Upvotes: 1

Views: 42

Answers (1)

Reedinationer
Reedinationer

Reputation: 5774

It sounds to me like you can implement logic based on i (your iteration count). Maybe something like this would suit you (I'm not sure what intent you have with flag so I removed it):

import threading

def some_signal():
    print(threading.currentThread().getName(), 'Get signal')

def post_proccesing():
    print(threading.currentThread().getName(), 'Process the signa;')

for i in range(5):
    if i: # means i > 0 because 0 -> False
        t = threading.Thread(target=some_signal) # use default name
        # removed 'else' statement because you need to have a 'w' variable for your call to 'w.start()'
        w = threading.Thread(target=post_proccesing) # use default name
        t.start()
        w.start()
    else: # case where i == 0 -> first iteration
        some_signal()
        post_proccesing()

Output:

MainThread Get signal
MainThread Process the signa;
Thread-1 Get signal
Thread-2 Process the signa;
Thread-3 Get signal
Thread-4 Process the signa;
Thread-5 Get signal
Thread-6 Process the signa;
Thread-7 Get signal
Thread-8 Process the signa;

Upvotes: 1

Related Questions