path: root/src/common/evdp_epoll.c

//
// Event Dispatcher Abstraction for EPOLL
//
// Author: Florian Wilkemeyer <fw@f-ws.de>
//
// Copyright (c) rAthena Project (www.rathena.org) - Licensed under GNU GPL
// For more information, see LICENCE in the main folder
//
//

#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

#include <sys/epoll.h>
#include <sys/fcntl.h>
#include <sys/socket.h>

#include "../common/cbasetypes.h"
#include "../common/showmsg.h"
#include "../common/evdp.h"


#define EPOLL_MAX_PER_CYCLE 10  // Max Events to coalesc. per cycle. 


static int epoll_fd = -1;


void evdp_init()
{

    epoll_fd = epoll_create(EPOLL_MAX_PER_CYCLE);
    if (epoll_fd == -1) {
        ShowFatalError("evdp [EPOLL]: Cannot create event dispatcher (errno: %u / %s)\n", errno, strerror(errno));
        exit(1);
    }

}//end: evdp_init()


void evdp_final()
{

    if (epoll_fd != -1) {
        close(epoll_fd);
        epoll_fd = -1;
    }

}//end: evdp_final()


int32 evdp_wait(EVDP_EVENT *out_fds, int32 max_events, int32 timeout_ticks)
{
    struct epoll_event l_events[EPOLL_MAX_PER_CYCLE];
    register struct epoll_event *ev;
    register int nfds, n;

    if (max_events > EPOLL_MAX_PER_CYCLE)
        max_events = EPOLL_MAX_PER_CYCLE;

    nfds = epoll_wait(epoll_fd,  l_events,      max_events,     timeout_ticks);
    if (nfds == -1) {
        // @TODO: check if core is in shutdown mode.  if - ignroe error.

        ShowFatalError("evdp [EPOLL]: epoll_wait returned bad / unexpected status (errno: %u / %s)\n", errno, strerror(errno));
        exit(1); //..
    }

    // Loop thru all events and copy it to the local ra evdp_event.. struct.
    for (n = 0; n < nfds; n++) {
        ev = &l_events[n];

        out_fds->fd = ev->data.fd;
        out_fds->events = 0; // clear

        if (ev->events & EPOLLHUP)
            out_fds->events |= EVDP_EVENT_HUP;

        if (ev->events & EPOLLIN)
            out_fds->events |= EVDP_EVENT_IN;

        if (ev->events & EPOLLOUT)
            out_fds->events |= EVDP_EVENT_OUT;

        out_fds++;
    }

    return nfds; // 0 on timeout or > 0  ..
}//end: evdp_wait()


void evdp_remove(int32 fd,  EVDP_DATA *ep)
{

    if (ep->ev_added == true) {

        if (epoll_ctl(epoll_fd,  EPOLL_CTL_DEL,  fd,  &ep->ev_data)  != 0) {
            ShowError("evdp [EPOLL]: evdp_remove - epoll_ctl (EPOLL_CTL_DEL) failed! fd #%u (errno %u / %s)\n", fd,  errno, strerror(errno));
        }

        ep->ev_data.events = 0; // clear struct.
        ep->ev_data.data.fd = -1; // .. clear struct ..

        ep->ev_added = false; // not added!
    }


}//end: evdp_remove()


bool evdp_addlistener(int32 fd, EVDP_DATA *ep)
{

    ep->ev_data.events = EPOLLET|EPOLLIN;
    ep->ev_data.data.fd = fd;

    // No check here for 'added ?'
    // listeners cannot be added twice.
    //
    if (epoll_ctl(epoll_fd,  EPOLL_CTL_ADD,  fd,  &ep->ev_data) != 0) {
        ShowError("evdp [EPOLL]: evdp_addlistener - epoll_ctl (EPOLL_CTL_ADD) faield! fd #%u (errno %u / %s)\n", fd, errno, strerror(errno));
        ep->ev_data.events = 0;
        ep->ev_data.data.fd = -1;
        return false;
    }

    ep->ev_added = true;

    return true;
}//end: evdp_addlistener()


bool evdp_addclient(int32 fd, EVDP_DATA *ep)
{

    ep->ev_data.events = EPOLLIN | EPOLLHUP;
    ep->ev_data.data.fd = fd;

    // No check for "added?" here,
    // this function only gets called upon accpept.
    //

    if (epoll_ctl(epoll_fd,  EPOLL_CTL_ADD,  fd, &ep->ev_data) != 0) {
        ShowError("evdp [EPOLL]: evdp_addclient - epoll_ctl (EPOLL_CTL_ADD) failed! fd #%u (errno %u / %s)\n", fd, errno, strerror(errno));
        ep->ev_data.events = 0;
        ep->ev_data.data.fd = -1;
        return false;
    }

    ep->ev_added = true;

    return true;
}//end: evdp_addclient()


bool evdp_addconnecting(int32 fd, EVDP_DATA *ep)
{

    ep->ev_data.events = EPOLLET | EPOLLOUT | EPOLLHUP;
    ep->ev_data.data.fd = fd;

    if (epoll_ctl(epoll_fd,  EPOLL_CTL_ADD,  fd, &ep->ev_data) != 0) {
        ShowError("evdp [EPOLL]: evdp_addconnecting - epoll_ctl (EPOLL_CTL_ADD) failed! fd #%u (errno %u / %s)\n", fd, errno, strerror(errno));
        ep->ev_data.events = 0;
        ep->ev_data.data.fd = -1;
    }

    ep->ev_added = true;

    return true;
}//end: evdp_addconnecting()


bool evdp_outgoingconnection_established(int32 fd, EVDP_DATA *ep)
{
    int32 saved_mask;

    if (ep->ev_added != true) {
        // !
        ShowError("evdp [EPOLL]: evdp_outgoingconnection_established fd #%u is not added to event dispatcher! invalid call.\n", fd);
        return false;
    }

    saved_mask = ep->ev_data.events;

    ep->ev_data.events = EPOLLIN | EPOLLHUP;

    if (epoll_ctl(epoll_fd,  EPOLL_CTL_MOD,  fd, &ep->ev_data) != 0) {
        ep->ev_data.events = saved_mask; // restore old mask.
        ShowError("evdp [EPOLL]: evdp_outgoingconnection_established - epoll_ctl (EPOLL_CTL_MOD) failed! fd #%u (errno %u / %s)\n", fd, errno, strerror(errno));
        return false;
    }

    return true;
}//end: evdp_outgoingconnection_established()


bool evdp_writable_add(int32 fd, EVDP_DATA *ep)
{

    if (ep->ev_added != true) {
        ShowError("evdp [EPOLL]: evdp_writable_add - tried to add not added fd #%u\n",fd);
        return false;
    }

    if (!(ep->ev_data.events  & EPOLLOUT)) { //

        ep->ev_data.events |= EPOLLOUT;
        if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, fd, &ep->ev_data) != 0) {
            ShowError("evdp [EPOLL]: evdp_writable_add - epoll_ctl (EPOLL_CTL_MOD) failed! fd #%u (errno: %u / %s)\n", fd, errno, strerror(errno));
            ep->ev_data.events &= ~EPOLLOUT; // remove from local flagmask due to failed syscall.
            return false;
        }
    }

    return true;
}//end: evdp_writable_add()


void evdp_writable_remove(int32 fd, EVDP_DATA *ep)
{

    if (ep->ev_added != true) {
        ShowError("evdp [EPOLL]: evdp_writable_remove - tried to remove not added fd #%u\n", fd);
        return;
    }

    if (ep->ev_data.events & EPOLLOUT) {

        ep->ev_data.events &= ~EPOLLOUT;
        if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, fd, &ep->ev_data) != 0) {
            ShowError("evdp [EPOLL]: evdp_writable_remove - epoll_ctl (EPOLL_CTL_MOD) failed! fd #%u (errno %u / %s)\n", fd, errno, strerror(errno));
            ep->ev_data.events |= EPOLLOUT; // add back to local flagmask because of failed syscall.
            return;
        }
    }

    return;
}//end: evdp_writable_remove()