Hello,
I am trying to have two python scripts running where one pauses the other. Both scripts do some socket communication (one reads and one writes)
read.py runs continously in the background with a 60 second sleep after each run.
write.py will be run by user interaction/click on a webpage.
These two cannot run at the same time (comm errors). So write.py will need to pause read.py, run, then reactivate write.py.
I am probably looking into this the wrong way. But how would write.py fetch the process of read.py?
Thanks in advance for any tips,
Per
This sounds like a simple sort of 'Distributed agreement' (in Distributed software design)
I say simple, but the process of managing is not simple.
One way this can be achieved is by inserting a process called a dispatcher into the system. Think of it as a process like
the dispatcher of an emergency center, or a cab company.
The job of the dispatcher is to keep track of all 'courier' processes, and to dispatch, and monitor, time slots,
for each:
Example:
- Task 1 asks dispatcher for permission to communicate with task3.
- Dispatcher knows that this task cannot be done concurrently, and that Task 3 is busy.
- It sends Task 1 a message that says 'Not now'
- A bit later, task 1 asks for permission again
- Task 3 is free, so dispatcher gives the OK, but indicates that Task1 must report back when the task is complete.
- The dispatcher also issues an allotted amount of time in which to finish the task.
- Once task 1 has been notified, dispatcher starts a timer for that task.
- if task 1 reports back before that timer times out, dispatcher stops the timer and marks task 3 as being available to other users.
- If task 1 doesn't report back in the allotted time, the dispatcher will attempt to contact task 3 and ask if busy. If it does not get a response within an allotted time (from the 'are you busy' request), it will assume that something is wrong with task 3 and will reinitialize the task 3 process (make it ready to receive requests, reboot or reset).
- Task 3 may be able to handle more than one task at a time if so, task 1 may be allowed to go on without notification of completion.
- and so on.
In order to learn how to do this sort of thing, google for 'Distributed Software Design, Challenges and solutions'
and/or 'distributed agreements'.
For example:
http://help.callassoftware.com/m/62791/l...processing
or:
https://www.embedded.com/design/prototyp...-Solutions
first one uses commercial software, but has good explanation