Reading UserAlgo.BgCplc[i] within a CPLC

[alejandrojginerd]

Inside a BgCPLC I have created a nodetree that was dynamically allocated. I am trying to implement a way to free up this memory when the BgCPLC is disabled.

As no code will the run when the cplc is disabled ithought of freeing the memory the next time it is enabled, therefore I need to keep track of the previeus UserAlgo.BgCplc[i] state. I thougt of having another CPLC running that stores the UserAlgo.BgCplc[i] value into a shared P variable but this seems to be an excesivelly cumbersome solution. Is there a cleaner way to achive this behaviour?

#include <stdbool.h>

static bool initialized;

int user_plcc() {

        if (prev_UserAlgoBgCplc[i] = 0 && initialized){ // if it was previusly turned off and its not the first run

        free(root);

        initialized = false;

    }

    if (!initialized) // initialize the node tree

    {

        // Constructing the tree

        root = createNode(node, num_children)     // fills the node using malloc depending on the number of children

        initialized = true;

    }

    if (prev_UserAlgoBgCplc[i] = 0 && !initialized){ // if it was previusly turned off and its not the first run

        free(root);

    }

}

[DaveBarnett]

The way I cleanly shut down background C programs is to have a global var that I set in script that instructs the C program to clean up and exit.  ‘Downside is C program must be continually monitoring that var.