Having issues running a python script with threading from within matlab. It appears that matlab stops the python interpreter much of the time. At the end of the message I have a python script that starts a thread and looks at its iterations, without and with a small amount of sleep within the script.
My python version is 2.7.9 64bit. No other versions of python have been installed (clean machine built 2 weeks ago)
Lots of iterations when run from the DOS command line :
>>python process_test.py
run for 3.0 seconds:
2485 585859 1126612 1669999 2208775 2754896 3226523
iterations no sleep : 3226523
1 501 1000 1500 2000 2497 2997
iterations with sleep : 2998
Or even from within matlab when using system:
system('python process_test.py')
But, using a matlab script:
insert(py.sys.path,int32(0),'.');
p = py.process_test.process_test(0.001,3);
ts = now + 5/86400.;
while now < ts
disp(p.cnt);
pause(0.5);
end
disp(sprintf('Iterations w sleep %d', p.cnt));
There are zero iterations (with or without python sleep)
However, starting from the matlab command line and can poll and get some cnts. p = py.process_test.process_test(0.001,3); wait a bit then type p.cnt or p to see all the members
My final application is real-time plotting with python reading data from a TCPIP connection in a thread. In this case, the thread does run, but not enought or consistently. I suspect that calling drawnow expose many many times per sec was giving the python interpreter a chance to run.
The python script "process_test.py" follows:
import threading
import time, sys
class process_test(threading.Thread) :
def __init__(self, sleep_tm=0.001, watchdog_timeout=5) :
self.cnt = 0;
self.sleep_tm = sleep_tm;
self.terminate = False
self.time_of_last_watchdog = time.clock();
self.watchdog_timeout = watchdog_timeout;
threading.Thread.__init__(self)
self.start()
def __del__(self) :
self.terminate = True
def run(self) :
self.time_of_last_loop = time.clock()
while not self.terminate :
self.cnt += 1
t = time.clock()
dt = t - self.time_of_last_watchdog;
if dt > self.watchdog_timeout:
self.terminate = True
dt = t - self.time_of_last_loop
self.time_of_last_loop = t;
if self.sleep_tm > 1.0e-4 : #
time.sleep(self.sleep_tm);
if __name__ == "__main__" :
tmout = 3;
print "run for %.1f seconds:"
p = process_test(0,tmout)
ts = time.clock() + tmout+0.1;
while time.clock() < ts :
print p.cnt,
time.sleep(0.5)
print
print "iterations no sleep : ", p.cnt
print
print
p = process_test(0.001, tmout)
ts = time.clock() + tmout + 0.1;
while time.clock() < ts:
print p.cnt,
time.sleep(0.5)
print
print "iterations with sleep : ", p.cnt
sys.exit()
