I have a python wrapper holding some c++ code. In it is a function that I setup as a process from my python code. Its a while statement that I need to setup a condition for when it should shut down.
the while statement more or less is
while(TERMINATE == 0)
I have data that is being sent back from within the while loop. I'm using pipe() to create 'in' and 'out' objects. I send the 'out' object to the function when I create the process.
self.stream = Process(target=fxn, args=(self.outPipe,))
while inside the wrapper I am able to send data back to the python script with
PyObject *send = Py_BuildValue("s", "send_bytes");
PyObject_CallMethodObjArgs(pipe, send, temp, NULL);
This works just fine.
However, I'm having issues with sending a message to the C++ code, in the wrapper, that tells the loop to stop.
What I have tried:
What I figured I would do is just check poll(). When the system sees that there is an incoming signal from the python script it would set TERMINATE = 1. so i wrote this.
PyObject *poll = Py_BuildValue("p", "poll");
p (bool) [int]
Tests the value passed in for truth (a boolean predicate) and converts the result to its equivalent C true/false integer value. Sets the int to 1 if the expression was true and 0 if it was false. This accepts any valid Python value. See Truth Value Testing for more information about how Python tests values for truth.
As I'm expecting a true or false from the python function poll(). I figured "p" would be ideal as it would convert true to 1 and false to 0.
in the loop I have
if(PyObject_CallMethodObjArgs(pipe, poll, NULL, NULL))
TERMINATE = 1;
I wanted to use poll() as its non-blocking, like recv() is. This way I could just go about my other work and check poll() once a cycle.
however, when I send a signal from the python script it never trips.