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Recursion in embedded system

g p

Hi,
Can anybody give an insight whether this is good or not in embedded environment?
I have a function which call itself when a condition is false, see code sample below:

void Test(void)
{
   U8 temp;
   U8 temp1;
   U16 temp2;
   U16 temp3;

   if(some_extern_flag)
   {
      //Exit to this function
   }
   else
   {
     Test();   //Call me again
   }
}

Does it create memory leak when called many times, say 5 times the flag is false, it will call itself 5x?
This function doesn't called from either ISR or other function, just within it.
Will this create a problem later on?

thanks
gp

Parents
  • 0 in reply to ²erik malund

    Another thing is that the above case may not result in any recursion, depending on if the specific compiler supports optimization for tail-end recursion, i.e. when the function is calling itself directly before exiting. Then the recursive call can be replaced with a jump to the start of the function, basically modifying the function into:

    void Test(void)
{
   U8 temp;
   U8 temp1;
   U16 temp2;
   U16 temp3;

   for (;;) {
        if(some_extern_flag) {
            //Exit to this function
            return;
       } else {
            continue;    // Instead of recursion, just restart our loop.
       }
       break;
    }
}

Reply
  • 0 in reply to ²erik malund

    Another thing is that the above case may not result in any recursion, depending on if the specific compiler supports optimization for tail-end recursion, i.e. when the function is calling itself directly before exiting. Then the recursive call can be replaced with a jump to the start of the function, basically modifying the function into:

    void Test(void)
{
   U8 temp;
   U8 temp1;
   U16 temp2;
   U16 temp3;

   for (;;) {
        if(some_extern_flag) {
            //Exit to this function
            return;
       } else {
            continue;    // Instead of recursion, just restart our loop.
       }
       break;
    }
}

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