🚀 go-pugleaf

Hello,

I have found the following pseudo code of a very efficient fifo queue
that doen't use any CAS
just an XADD , and i want to ask you if someone can translate it to
Delphi and basm .

Here it is:

pseudo-code for a mpmc bounded queue of doubles:
______________________________________________
struct cell { uint32_t ver; double state; };


uint32_t head = 0;
uint32_t tail = 0;
cell cells[N]; // N must be a power of 2


void init() {
    for (uint32_t i = 0; i < N; ++i) cells.ver = i;



}


void producer(double state) {
    uint32_t ver = XADD(&head, 1);
    cell& c = cells[ver & (N - 1)];
    while (LOAD(&c.ver) != ver) backoff();
    c.state = state;
    STORE(&c.ver, ver + 1);


}


double consumer() {
    uint32_t ver = XADD(&tail, 1);
    cell& c = cells[ver & (N - 1)];
    while (LOAD(&c.ver) != ver + 1) backoff();
    double state = c.state;
    STORE(&c.ver, ver + N);
    return state;

}

______________________________________________



And here is the link it's by invented by:


Chris M. Thomasson


here is his message on usenet on the following forum:

comp.programming.threads

http://groups.google.com/group/comp.programming.threads/browse_thread/thread/f9cab03871241455#



Best regards,

Amine Moulay Ramdane.