vitastor/ringloop.cpp

#include "ringloop.h"

ring_loop_t::ring_loop_t(int qd)
{
    int ret = io_uring_queue_init(qd, &ring, 0);
    if (ret < 0)
    {
        throw std::runtime_error(std::string("io_uring_queue_init: ") + strerror(-ret));
    }
    ring_data = (struct ring_data_t*)malloc(sizeof(ring_data_t) * ring.sq.ring_sz);
    if (!ring_data)
    {
        throw std::bad_alloc();
    }
}

ring_loop_t::~ring_loop_t()
{
    free(ring_data);
    io_uring_queue_exit(&ring);
}

int ring_loop_t::register_consumer(ring_consumer_t & consumer)
{
    consumer.number = consumers.size();
    consumers.push_back(consumer);
    return consumer.number;
}

void ring_loop_t::unregister_consumer(int number)
{
    if (number < consumers.size())
    {
        consumers[number].loop = NULL;
    }
}

void ring_loop_t::loop(bool sleep)
{
    // FIXME: we should loop until all "coroutines" are suspended. currently we loop only once before sleeping
    struct io_uring_cqe *cqe;
    while (!io_uring_peek_cqe(&ring, &cqe))
    {
        struct ring_data_t *d = (struct ring_data_t*)cqe->user_data;
        if (d->callback)
        {
            d->res = cqe->res;
            d->callback(d);
        }
        io_uring_cqe_seen(&ring, cqe);
    }
    for (int i = 0; i < consumers.size(); i++)
    {
        consumers[i].loop();
    }
    if (sleep)
    {
        io_uring_wait_cqe(&ring, &cqe);
    }
}