Question

How does one implement a multithreaded single process model in linux fedora under c where a single scheduler is used on a “main” core reading i/o availability (ex. tcp/ip, udp) then having a single-thread-per-core (started at init), the “execution thread”, parse the data then update a small amount of info update to shared memory space (it is my understanding pthreads share data under a single process).

I beleive my options are:

Pthreads or the linux OS scheduler

I have a naive model in mind consisting of starting a certain number of these execution threads a single scheduler thread.

What is the best solution one could think when I know that I can use this sort of model.

Answer 1

Completing Benoit’s answer, in order to communicate between your master and your worker threads, you could use conditional variable. The workers do something like:

while (true)
{
    pthread_mutex_lock(workQueueMutex);
    while (workQueue.empty())
        pthread_cond_wait(workQueueCond, workQueueMutex);
    /* if we get were then (a) we have work (b) we hold workQueueMutex */
    work = pop(workQueue);
    pthread_mutex_unlock(workQueueMutex);
    /* do work */
}

and the master:

/* I/O received */
pthread_mutex_lock(workQueueMutex);
push(workQueue, work);
pthread_cond_signal(workQueueCond);
pthread_mutex_unlock(workQueueMutex);

This would wake up one idle work to immediately process the request. If no worker is available, the work will be dequeued and processed later.