/*
 * Copyright (c) 2013 Joris Vink <joris@coders.se>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/epoll.h>
#include <sys/prctl.h>

#include <sched.h>

#include "kore.h"

static int			efd = -1;
static u_int32_t		event_count = 0;
static struct epoll_event	*events = NULL;

void
kore_platform_init(void)
{
	long		n;

	if ((n = sysconf(_SC_NPROCESSORS_ONLN)) == -1) {
		kore_debug("could not get number of cpu's falling back to 1");
		cpu_count = 1;
	} else {
		cpu_count = (u_int16_t)n;
	}
}

void
kore_platform_worker_setcpu(struct kore_worker *kw)
{
	cpu_set_t	cpuset;

	CPU_ZERO(&cpuset);
	CPU_SET(kw->cpu, &cpuset);
	if (sched_setaffinity(0, sizeof(cpu_set_t), &cpuset) == -1) {
		kore_debug("kore_worker_setcpu(): %s", errno_s);
	} else {
		kore_debug("kore_worker_setcpu(): worker %d on cpu %d",
		    kw->id, kw->cpu);
	}
}

void
kore_platform_event_init(void)
{
	if ((efd = epoll_create(10000)) == -1)
		fatal("epoll_create(): %s", errno_s);

	event_count = worker_max_connections + nlisteners;
	events = kore_calloc(event_count, sizeof(struct epoll_event));
}

void
kore_platform_event_wait(void)
{
	struct connection	*c;
	struct listener		*l;
	u_int8_t		type;
	int			n, i;

	n = epoll_wait(efd, events, event_count, 100);
	if (n == -1) {
		if (errno == EINTR)
			return;
		fatal("epoll_wait(): %s", errno_s);
	}

	if (n > 0)
		kore_debug("main(): %d sockets available", n);

	for (i = 0; i < n; i++) {
		if (events[i].data.ptr == NULL)
			fatal("events[%d].data.ptr == NULL", i);

		type = *(u_int8_t *)events[i].data.ptr;

		if (events[i].events & EPOLLERR ||
		    events[i].events & EPOLLHUP) {
			if (type == KORE_TYPE_LISTENER)
				fatal("failed on listener socket");

			c = (struct connection *)events[i].data.ptr;
			kore_connection_disconnect(c);
			continue;
		}

		if (type == KORE_TYPE_LISTENER) {
			l = (struct listener *)events[i].data.ptr;

			while ((worker->accepted < worker->accept_treshold) &&
			    (worker_active_connections <
			    worker_max_connections)) {
				kore_connection_accept(l, &c);
				if (c == NULL)
					break;

				worker->accepted++;
				kore_platform_event_schedule(c->fd,
				    EPOLLIN | EPOLLOUT | EPOLLET, 0, c);
			}
		} else {
			c = (struct connection *)events[i].data.ptr;
			if (events[i].events & EPOLLIN &&
			    !(c->flags & CONN_READ_BLOCK))
				c->flags |= CONN_READ_POSSIBLE;
			if (events[i].events & EPOLLOUT &&
			    !(c->flags & CONN_WRITE_BLOCK))
				c->flags |= CONN_WRITE_POSSIBLE;

			if (!kore_connection_handle(c))
				kore_connection_disconnect(c);
		}
	}
}

void
kore_platform_event_schedule(int fd, int type, int flags, void *udata)
{
	struct epoll_event	evt;

	kore_debug("kore_platform_event(%d, %d, %d, %p)",
	    fd, type, flags, udata);

	evt.events = type;
	evt.data.ptr = udata;
	if (epoll_ctl(efd, EPOLL_CTL_ADD, fd, &evt) == -1) {
		if (errno == EEXIST) {
			if (epoll_ctl(efd, EPOLL_CTL_MOD, fd, &evt) == -1)
				fatal("epoll_ctl() MOD: %s", errno_s);
		} else {
			fatal("epoll_ctl() ADD: %s", errno_s);
		}
	}
}

void
kore_platform_enable_accept(void)
{
	struct listener		*l;

	LIST_FOREACH(l, &listeners, list)
		kore_platform_event_schedule(l->fd, EPOLLIN, 0, l);
}

void
kore_platform_disable_accept(void)
{
	struct listener		*l;

	LIST_FOREACH(l, &listeners, list) {
		if (epoll_ctl(efd, EPOLL_CTL_DEL, l->fd, NULL) == -1)
			fatal("kore_platform_disable_accept: %s", errno_s);
	}
}

void
kore_platform_proctitle(char *title)
{
	if (prctl(PR_SET_NAME, title) == -1)
		kore_debug("prctl(): %s", errno_s);
}