How to run two functions simultaneously
function, multithreading, python, synchronization, testing
Solution
If you want to use the common Python implementation (CPython), you can certainly use the multiprocessing module, which does wonders (you can pass non-pickleable arguments to subprocesses, kill tasks,…), offers an interface similar to that of threads, and does not suffer from the Global Interpreter Lock.
The downside is that subprocesses are spawned, which takes more time than creating threads; this should only be a problem if you have many, many short tasks. Also, since data is passed (via serialization) between processes, large data both takes a long time to pass around and ends up having a large memory footprint (as it is duplicated between each process). In situations where each task takes a "long" time and the data in and out of each task is not too large, the multiprocessing module should be great.
Problem
I am running test but I want to run 2 functions at the same time. I have a camera and I am telling it to move via suds, I am then logging into the camera via SSH to check the speed the camera is set to. When I check the speed the camera has stopped so no speed is available. Is there a way I can get these functions to run at the same time to test the speed of the camera. Sample code is below: ``` class VerifyPan(TestAbsoluteMove): def runTest(self): self.dest.PanTilt._x=350 # Runs soap move command threading.Thread(target = SudsMove).start() self.command = './ptzpanposition -c 0 -u degx10' # Logs into camera and checks speed TestAbsoluteMove.Ssh(self) # Position of the camera verified through Ssh (No decimal point added to the Ssh value) self.assertEqual(self.Value, '3500') ``` I have now tried the threading module as mentioned below. The thread does not run in sync with the function TestAbsoluteMove.Ssh(). Is there any other code I need to make this work. I have looked at putting arguments into the thread statement that state the thread runs when the Ssh() function. Does anyone know what to enter in this statement? Sorry if I haven't explained correctly. The 'SudsMove' function moves the camera and the 'Ssh' function logs into the camera and checks the speed the camera is currently moving at. The problem is that by the time the 'Ssh' function logs in the camera has stopped. I need both functions to run in parallel so I can check the camera speed while it is still moving. Thanks