Volatile Variable

​x
 
// volatile 
int flag; // global memory is part of "BSS" section, guaranteed to be zero (unless a bug in startup code)
​
void flag_setter_task(void *p) {
  while (1) {
    ++flag;
    vTaskDelay(1000);
  }
}
​
void flag_checker_task(void *p) {
  puts("Task entry");
​
  while (1) {
    flag = 0;
    while (0 == flag) {
      ;
    }
​
    puts("flag has incremented away from value of 0");
    vTaskDelay(1000);
  }
}

Interview Questions

What is a volatile keyword?
Given a code snippet, why you cannot set a breakpoint?
Is const opposite of volatile?
What is the point of "const volatile *variable" ?
- You as a programmer, cannot write a line of code to modify, but maybe DMA or a peripheral behind you can modify it