module system.lock;

// Itinerations of a spinlock necessary to call it a deadlock
immutable ulong deadlockItinerations = 35000000;

// The lock information, 1 if locked, 0 if not
alias Lock = ubyte;

// Test a lock, if its locked, wait for it to unlock, if not lock it.
void adquireLock(Lock* lock) {
    import core.bitop;
    import util.term;

    if (volatileLoad(lock)) {
        // Spinlock
        ulong itinerations = 0;

        if (volatileLoad(lock)) {
            if (++itinerations == deadlockItinerations) {
                warning("Potential spinlock in core #%u");
                itinerations = 0;
            }
        }
    } else volatileStore(lock, 1);
}

// Release an used lock
void lockRelease(Lock* lock) {
    import core.bitop;
    import util.term;

    if (!volatileLoad(lock)) {
        panic("Trying to release an already released lock");
    }

    volatileStore(lock, 0);
}