Question

Let’s say I have one Mutex, two threads, one function and one cycle (Pseudo code).
Function:

void Update(){
    Mutex.enter();
    ...// time: 10 ms
    Mutex.leave();
}

Main.cpp:

void main(){
    ...// Starting thread
    while(true)
        Update();
}

Thread:

void Thread(void *){
    Mutex.enter();
    ... // 
    Mutex.leave();
}

But Function calls constantly, so Mutex small time is free. How high chance Thread have to enter in Mutex? If low, how it can be resolved?

Answer 1

If you’re using boost threads (link), then I’d use yield(). It’ll allow any other “waiting” threads to “get a chance” to run.

There’s probably a win32 or pthreads way of doing this too.

Edit: and by the way, use yield() outside of the locks. If it’s inside the locks, obviously that would be useless.

Edit2: And here’s the functions for different platforms:

• Win32: SwitchToThread() msdn link.
• Linux/Unix pthreads: `pthread_yield()’ link

If you’re not on any of those platforms, read the descriptions at those links, and look for a function that does the same thing in your framework.