[ashd.git] / lib / mtio-epoll.c

/*
    ashd - A Sane HTTP Daemon
    Copyright (C) 2008  Fredrik Tolf <fredrik@dolda2000.com>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <fcntl.h>
#include <string.h>
#include <sys/epoll.h>
#include <errno.h>

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <log.h>
#include <utils.h>
#include <mt.h>
#include <mtio.h>

static struct blocker *blockers;

struct blocker {
    struct blocker *n, *p, *n2, *p2;
    int fd, reg;
    int ev;
    time_t to;
    struct muth *th;
};

static int epfd = -1, fdln = 0;
static int exitstatus;
static struct blocker **fdlist;

static int regfd(struct blocker *bl)
{
    struct blocker *o;
    struct epoll_event evd;
    
    memset(&evd, 0, sizeof(evd));
    evd.events = 0;
    if(bl->ev & EV_READ)
	evd.events |= EPOLLIN;
    if(bl->ev & EV_WRITE)
	evd.events |= EPOLLOUT;
    evd.data.fd = bl->fd;
    if(bl->fd >= fdln) {
	if(fdlist) {
	    fdlist = srealloc(fdlist, sizeof(*fdlist) * (bl->fd + 1));
	    memset(fdlist + fdln, 0, sizeof(*fdlist) * (bl->fd + 1 - fdln));
	    fdln = bl->fd + 1;
	} else {
	    fdlist = szmalloc(sizeof(*fdlist) * (fdln = (bl->fd + 1)));
	}
    }
    if(fdlist[bl->fd] == NULL) {
	if(epoll_ctl(epfd, EPOLL_CTL_ADD, bl->fd, &evd)) {
	    /* XXX?! Whatever to do, really? */
	    flog(LOG_ERR, "epoll_add on fd %i: %s", bl->fd, strerror(errno));
	    return(-1);
	}
    } else {
	for(o = fdlist[bl->fd]; o; o = o->n2) {
	    if(o->ev & EV_READ)
		evd.events |= EPOLLIN;
	    if(o->ev & EV_WRITE)
		evd.events |= EPOLLOUT;
	}
	if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) {
	    /* XXX?! Whatever to do, really? */
	    flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno));
	    return(-1);
	}
    }
    bl->n2 = fdlist[bl->fd];
    bl->p2 = NULL;
    if(fdlist[bl->fd] != NULL)
	fdlist[bl->fd]->p2 = bl;
    fdlist[bl->fd] = bl;
    bl->reg = 1;
    return(0);
}

static void remfd(struct blocker *bl)
{
    struct blocker *o;
    struct epoll_event evd;
    
    if(!bl->reg)
	return;
    if(bl->n2)
	bl->n2->p2 = bl->p2;
    if(bl->p2)
	bl->p2->n2 = bl->n2;
    if(bl == fdlist[bl->fd])
	fdlist[bl->fd] = bl->n2;
    if(fdlist[bl->fd] == NULL) {
	if(epoll_ctl(epfd, EPOLL_CTL_DEL, bl->fd, NULL))
	    flog(LOG_ERR, "epoll_del on fd %i: %s", bl->fd, strerror(errno));
    } else {
	memset(&evd, 0, sizeof(evd));
	evd.events = 0;
	evd.data.fd = bl->fd;
	for(o = fdlist[bl->fd]; o; o = o->n2) {
	    if(o->ev & EV_READ)
		evd.events |= EPOLLIN;
	    if(o->ev & EV_WRITE)
		evd.events |= EPOLLOUT;
	}
	if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) {
	    /* XXX?! Whatever to do, really? */
	    flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno));
	}
    }
    bl->reg = 0;
}

int block(int fd, int ev, time_t to)
{
    struct blocker *bl;
    int rv;
    
    omalloc(bl);
    bl->fd = fd;
    bl->ev = ev;
    if(to > 0)
	bl->to = time(NULL) + to;
    bl->th = current;
    if((epfd >= 0) && regfd(bl)) {
	free(bl);
	return(-1);
    }
    bl->n = blockers;
    if(blockers)
	blockers->p = bl;
    blockers = bl;
    rv = yield();
    if(bl->n)
	bl->n->p = bl->p;
    if(bl->p)
	bl->p->n = bl->n;
    if(bl == blockers)
	blockers = bl->n;
    remfd(bl);
    free(bl);
    return(rv);
}

int ioloop(void)
{
    struct blocker *bl, *nbl;
    struct epoll_event evr[16];
    int i, fd, nev, ev, toval;
    time_t now, timeout;
    
    exitstatus = 0;
    epfd = epoll_create(128);
    fcntl(epfd, F_SETFD, FD_CLOEXEC);
    for(bl = blockers; bl; bl = nbl) {
	nbl = bl->n;
	if(regfd(bl))
	    resume(bl->th, -1);
    }
    while(blockers != NULL) {
	timeout = 0;
	for(bl = blockers; bl; bl = bl->n) {
	    if((bl->to != 0) && ((timeout == 0) || (timeout > bl->to)))
		timeout = bl->to;
	}
	now = time(NULL);
	if(timeout == 0)
	    toval = -1;
	else if(timeout > now)
	    toval = (timeout - now) * 1000;
	else
	    toval = 1000;
	if(exitstatus)
	    break;
	nev = epoll_wait(epfd, evr, sizeof(evr) / sizeof(*evr), toval);
	if(nev < 0) {
	    if(errno != EINTR) {
		flog(LOG_CRIT, "ioloop: epoll_wait errored out: %s", strerror(errno));
		/* To avoid CPU hogging in case it's bad, which it
		 * probably is. */
		sleep(1);
	    }
	    continue;
	}
	for(i = 0; i < nev; i++) {
	    fd = evr[i].data.fd;
	    ev = 0;
	    if(evr[i].events & EPOLLIN)
		ev |= EV_READ;
	    if(evr[i].events & EPOLLOUT)
		ev |= EV_WRITE;
	    if(evr[i].events & ~(EPOLLIN | EPOLLOUT))
		ev = -1;
	    for(bl = fdlist[fd]; bl; bl = nbl) {
		nbl = bl->n2;
		if((ev < 0) || (ev & bl->ev))
		    resume(bl->th, ev);
	    }
	}
	now = time(NULL);
	for(bl = blockers; bl; bl = nbl) {
	    nbl = bl->n;
	    if((bl->to != 0) && (bl->to <= now))
		resume(bl->th, 0);
	}
    }
    for(bl = blockers; bl; bl = bl->n)
	remfd(bl);
    close(epfd);
    epfd = -1;
    return(exitstatus);
}

void exitioloop(int status)
{
    exitstatus = status;
}
Commit	Line	Data
a6cda4dd FT	1	/*
	2	ashd - A Sane HTTP Daemon
	3	Copyright (C) 2008 Fredrik Tolf <fredrik@dolda2000.com>
	4
	5	This program is free software: you can redistribute it and/or modify
	6	it under the terms of the GNU General Public License as published by
	7	the Free Software Foundation, either version 3 of the License, or
	8	(at your option) any later version.
	9
	10	This program is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	GNU General Public License for more details.
	14
	15	You should have received a copy of the GNU General Public License
	16	along with this program. If not, see <http://www.gnu.org/licenses/>.
	17	*/
	18
	19	#include <stdlib.h>
4f6d772e FT	20	#include <unistd.h>
4f6d772e FT	21	#include <time.h>
be078ac9	22	#include <fcntl.h>
a6cda4dd FT	23	#include <string.h>
	24	#include <sys/epoll.h>
	25	#include <errno.h>
	26
	27	#ifdef HAVE_CONFIG_H
	28	#include <config.h>
	29	#endif
	30	#include <log.h>
	31	#include <utils.h>
	32	#include <mt.h>
	33	#include <mtio.h>
	34
	35	static struct blocker *blockers;
	36
	37	struct blocker {
	38	struct blocker n, p, n2, p2;
	39	int fd, reg;
	40	int ev;
	41	time_t to;
	42	struct muth *th;
	43	};
	44
	45	static int epfd = -1, fdln = 0;
9d32586e	46	static int exitstatus;
a6cda4dd FT	47	static struct blocker **fdlist;
	48
	49	static int regfd(struct blocker *bl)
	50	{
	51	struct blocker *o;
	52	struct epoll_event evd;
	53
	54	memset(&evd, 0, sizeof(evd));
	55	evd.events = 0;
	56	if(bl->ev & EV_READ)
	57	evd.events \|= EPOLLIN;
	58	if(bl->ev & EV_WRITE)
	59	evd.events \|= EPOLLOUT;
	60	evd.data.fd = bl->fd;
	61	if(bl->fd >= fdln) {
	62	if(fdlist) {
	63	fdlist = srealloc(fdlist, sizeof(fdlist) (bl->fd + 1));
	64	memset(fdlist + fdln, 0, sizeof(fdlist) (bl->fd + 1 - fdln));
	65	fdln = bl->fd + 1;
	66	} else {
	67	fdlist = szmalloc(sizeof(fdlist) (fdln = (bl->fd + 1)));
	68	}
	69	}
	70	if(fdlist[bl->fd] == NULL) {
	71	if(epoll_ctl(epfd, EPOLL_CTL_ADD, bl->fd, &evd)) {
	72	/* XXX?! Whatever to do, really? */
	73	flog(LOG_ERR, "epoll_add on fd %i: %s", bl->fd, strerror(errno));
	74	return(-1);
	75	}
	76	} else {
	77	for(o = fdlist[bl->fd]; o; o = o->n2) {
	78	if(o->ev & EV_READ)
	79	evd.events \|= EPOLLIN;
	80	if(o->ev & EV_WRITE)
	81	evd.events \|= EPOLLOUT;
	82	}
	83	if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) {
	84	/* XXX?! Whatever to do, really? */
	85	flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno));
	86	return(-1);
	87	}
	88	}
	89	bl->n2 = fdlist[bl->fd];
	90	bl->p2 = NULL;
	91	if(fdlist[bl->fd] != NULL)
	92	fdlist[bl->fd]->p2 = bl;
	93	fdlist[bl->fd] = bl;
	94	bl->reg = 1;
	95	return(0);
	96	}
	97
	98	static void remfd(struct blocker *bl)
	99	{
	100	struct blocker *o;
	101	struct epoll_event evd;
	102
	103	if(!bl->reg)
	104	return;
	105	if(bl->n2)
	106	bl->n2->p2 = bl->p2;
	107	if(bl->p2)
	108	bl->p2->n2 = bl->n2;
	109	if(bl == fdlist[bl->fd])
	110	fdlist[bl->fd] = bl->n2;
111	if(fdlist[bl->fd] == NULL) {
112	if(epoll_ctl(epfd, EPOLL_CTL_DEL, bl->fd, NULL))
113	flog(LOG_ERR, "epoll_del on fd %i: %s", bl->fd, strerror(errno));
114	} else {
115	memset(&evd, 0, sizeof(evd));
116	evd.events = 0;
117	evd.data.fd = bl->fd;
118	for(o = fdlist[bl->fd]; o; o = o->n2) {
119	if(o->ev & EV_READ)
120	evd.events \|= EPOLLIN;
121	if(o->ev & EV_WRITE)
122	evd.events \|= EPOLLOUT;
123	}
124	if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) {
125	/* XXX?! Whatever to do, really? */
126	flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno));
127	}
128	}
9d32586e	129	bl->reg = 0;
a6cda4dd FT	130	}
	131
	132	int block(int fd, int ev, time_t to)
	133	{
	134	struct blocker *bl;
	135	int rv;
	136
	137	omalloc(bl);
	138	bl->fd = fd;
	139	bl->ev = ev;
	140	if(to > 0)
	141	bl->to = time(NULL) + to;
	142	bl->th = current;
	143	if((epfd >= 0) && regfd(bl)) {
	144	free(bl);
	145	return(-1);
	146	}
	147	bl->n = blockers;
	148	if(blockers)
	149	blockers->p = bl;
	150	blockers = bl;
	151	rv = yield();
	152	if(bl->n)
	153	bl->n->p = bl->p;
	154	if(bl->p)
	155	bl->p->n = bl->n;
	156	if(bl == blockers)
	157	blockers = bl->n;
	158	remfd(bl);
	159	free(bl);
	160	return(rv);
	161	}
	162
9d32586e	163	int ioloop(void)
a6cda4dd FT	164	{
	165	struct blocker bl, nbl;
	166	struct epoll_event evr[16];
	167	int i, fd, nev, ev, toval;
	168	time_t now, timeout;
	169
9d32586e	170	exitstatus = 0;
a6cda4dd	171	epfd = epoll_create(128);
be078ac9	172	fcntl(epfd, F_SETFD, FD_CLOEXEC);
a6cda4dd FT	173	for(bl = blockers; bl; bl = nbl) {
	174	nbl = bl->n;
	175	if(regfd(bl))
	176	resume(bl->th, -1);
	177	}
	178	while(blockers != NULL) {
	179	timeout = 0;
	180	for(bl = blockers; bl; bl = bl->n) {
	181	if((bl->to != 0) && ((timeout == 0) \|\| (timeout > bl->to)))
	182	timeout = bl->to;
	183	}
	184	now = time(NULL);
	185	if(timeout == 0)
	186	toval = -1;
	187	else if(timeout > now)
	188	toval = (timeout - now) * 1000;
	189	else
	190	toval = 1000;
9d32586e FT	191	if(exitstatus)
9d32586e FT	192	break;
a6cda4dd FT	193	nev = epoll_wait(epfd, evr, sizeof(evr) / sizeof(*evr), toval);
	194	if(nev < 0) {
	195	if(errno != EINTR) {
f43decce	196	flog(LOG_CRIT, "ioloop: epoll_wait errored out: %s", strerror(errno));
a6cda4dd FT	197	/* To avoid CPU hogging in case it's bad, which it
	198	* probably is. */
	199	sleep(1);
	200	}
	201	continue;
	202	}
	203	for(i = 0; i < nev; i++) {
	204	fd = evr[i].data.fd;
	205	ev = 0;
	206	if(evr[i].events & EPOLLIN)
	207	ev \|= EV_READ;
	208	if(evr[i].events & EPOLLOUT)
	209	ev \|= EV_WRITE;
	210	if(evr[i].events & ~(EPOLLIN \| EPOLLOUT))
	211	ev = -1;
	212	for(bl = fdlist[fd]; bl; bl = nbl) {
	213	nbl = bl->n2;
	214	if((ev < 0) \|\| (ev & bl->ev))
	215	resume(bl->th, ev);
	216	}
	217	}
	218	now = time(NULL);
	219	for(bl = blockers; bl; bl = nbl) {
	220	nbl = bl->n;
	221	if((bl->to != 0) && (bl->to <= now))
	222	resume(bl->th, 0);
	223	}
	224	}
9d32586e FT	225	for(bl = blockers; bl; bl = bl->n)
9d32586e FT	226	remfd(bl);
a6cda4dd FT	227	close(epfd);
a6cda4dd FT	228	epfd = -1;
9d32586e FT	229	return(exitstatus);
	230	}
	231
	232	void exitioloop(int status)
	233	{
	234	exitstatus = status;
a6cda4dd	235	}