doompanning/src/doompanning.cc

#include <cstdlib>
#include <nng/nng.h>
#include <sys/types.h>
#include <unistd.h>
#include "dp_common.h"
#include "log.h"

static const char *CtrlUrl = "ipc://666_ctrl.socket"; // controller publishes here
static const char *DoomUrl = "ipc://666_doom.socket"; // dooms publish here
//static const char *CtrlUrl = "tcp://127.0.0.1:6666"; // controller publishes here
//static const char *DoomUrl = "tcp://127.0.0.1:6667"; // dooms publish here
static const size_t NumDooms = 3;

int run_controller(const size_t numDooms)
{
    nng_set_ncpu_max(1);
    nng_set_pool_thread_limit_max(1);
    nng_set_resolve_thread_max(1);

    auto pubSock = make_ctrl_pub(CtrlUrl);
    auto subSock = make_ctrl_sub(DoomUrl);

    size_t readyCount = 0;

    log_debug("ctrl waiting for hello from dooms");
    while (readyCount < numDooms)
    {
        char *buf = nullptr;
        size_t sz = 0;

        if (auto res = nng_recv(subSock, &buf, &sz, NNG_FLAG_ALLOC))
            dp_nng_fatal("run_ctrl/sub/go", res);

        log_debug("ctrl received %zu bytes from a doom", sz);
        nng_free(buf, sz);
        ++readyCount;
    }

    log_debug("ctrl is unleashing dooms");

    if (auto res = nng_send(pubSock, (void *)&readyCount, sizeof(readyCount), 0))
        dp_nng_fatal("run_ctrl/pub/unleash", res);

    nng_close(pubSock);
    nng_close(subSock);

    return 0;
}

int run_doom(const size_t id)
{
    log_debug("doom#%zu started", id);

    nng_set_ncpu_max(1);
    nng_set_pool_thread_limit_max(1);
    nng_set_resolve_thread_max(1);

    auto pubSock = make_doom_pub(DoomUrl);
    auto subSock = make_doom_sub(CtrlUrl);


    while (true) // FIXME: ctrl code does not work this way
    {
        log_debug("doom%zu sending hello", id);
        if (auto res = nng_send(pubSock, (void *)&id, sizeof(id), 0))
            dp_nng_fatal("run_doom/pub/hello", res);

        {
            char *buf = nullptr;
            size_t sz = 0;

            log_debug("doom%zu waiting for unleash", id);
            auto res = nng_recv(subSock, &buf, &sz, NNG_FLAG_ALLOC | NNG_FLAG_NONBLOCK);

            if (res == NNG_EAGAIN)
            {
                usleep(10 * 1000);
                continue;
            }
            else if (res)
                dp_nng_fatal("run_doom/sub/go", res);

            log_debug("doom%zu unleashed by %zu bytes!", id, sz);
            nng_free(buf, sz);
            break;
        }
    }

    nng_close(pubSock);
    nng_close(subSock);

    return 0;
}

int main(int argc, char *argv[])
{
    log_info("doompanning ctrl starting");

    for (size_t i=0; i<NumDooms; ++i)
    {
        auto res = fork();

        if (res == -1)
            dp_errno_fatal("spawn doom");
        else if (res == 0)
            return run_doom(i);
        else
            log_debug("spawned doom#%zu", i);
    }

    return run_controller(NumDooms);
}