[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, rev, id;
    int thpos;
    time_t to;
    struct muth *th;
};

struct timeentry {
    time_t to;
    struct blocker *bl;
};

static int epfd = -1, fdln = 0;
static int exitstatus;
static struct blocker **fdlist;
static typedbuf(struct timeentry) timeheap;

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;
}

static void thraise(struct timeentry ent, int n)
{
    int p;
    
    while(n > 0) {
	p = (n - 1) >> 1;
	if(timeheap.b[p].to <= ent.to)
	    break;
	timeheap.b[n] = timeheap.b[p];
	timeheap.b[n].bl->thpos = n;
	n = p;
    }
    timeheap.b[n] = ent;
    ent.bl->thpos = n;
}

static void thlower(struct timeentry ent, int n)
{
    int c;
    
    while(1) {
	c = (n << 1) + 1;
	if(c >= timeheap.d)
	    break;
	if((c + 1 < timeheap.d) && (timeheap.b[c + 1].to < timeheap.b[c].to))
	    c = c + 1;
	if(timeheap.b[c].to > ent.to)
	    break;
	timeheap.b[n] = timeheap.b[c];
	timeheap.b[n].bl->thpos = n;
	n = c;
    }
    timeheap.b[n] = ent;
    ent.bl->thpos = n;
}

static void addtimeout(struct blocker *bl, time_t to)
{
    sizebuf(timeheap, ++timeheap.d);
    thraise((struct timeentry){.to = to, .bl = bl}, timeheap.d - 1);
}

static void deltimeout(struct blocker *bl)
{
    struct timeentry ent;
    int n;
    
    if(bl->thpos == timeheap.d - 1) {
	timeheap.d--;
	return;
    }
    n = bl->thpos;
    ent = timeheap.b[--timeheap.d];
    if((n > 0) && (timeheap.b[(n - 1) >> 1].to > ent.to))
	thraise(ent, n);
    else
	thlower(ent, n);
}

static int addblock(struct blocker *bl)
{
    if((epfd >= 0) && regfd(bl))
	return(-1);
    bl->n = blockers;
    if(blockers)
	blockers->p = bl;
    blockers = bl;
    if(bl->to > 0)
	addtimeout(bl, bl->to);
    return(0);
}

static void remblock(struct blocker *bl)
{
    if(bl->to > 0)
	deltimeout(bl);
    if(bl->n)
	bl->n->p = bl->p;
    if(bl->p)
	bl->p->n = bl->n;
    if(blockers == bl)
	blockers = bl->n;
    remfd(bl);
}

struct selected mblock(time_t to, int n, struct selected *spec)
{
    int i, id;
    struct blocker bls[n];
    
    to = (to > 0)?(time(NULL) + to):0;
    for(i = 0; i < n; i++) {
	bls[i] = (struct blocker) {
	    .fd = spec[i].fd,
	    .ev = spec[i].ev,
	    .id = i,
	    .to = to,
	    .th = current,
	};
	if(addblock(&bls[i])) {
	    for(i--; i >= 0; i--)
		remblock(&bls[i]);
	    return((struct selected){.fd = -1, .ev = -1});
	}
    }
    id = yield();
    for(i = 0; i < n; i++)
	remblock(&bls[i]);
    if(id < 0)
	return((struct selected){.fd = -1, .ev = -1});
    return((struct selected){.fd = bls[id].fd, .ev = bls[id].rev});
}

int block(int fd, int ev, time_t to)
{
    struct blocker bl;
    int rv;
    
    bl = (struct blocker) {
	.fd = fd,
	.ev = ev,
	.id = -1,
	.to = (to > 0)?(time(NULL) + to):0,
	.th = current,
    };
    if(addblock(&bl))
	return(-1);
    rv = yield();
    remblock(&bl);
    return(rv);
}

int ioloop(void)
{
    struct blocker *bl, *nbl;
    struct epoll_event evr[16];
    int i, fd, nev, ev, toval;
    time_t now;
    
    exitstatus = 0;
    epfd = epoll_create(128);
    fcntl(epfd, F_SETFD, FD_CLOEXEC);
    bufinit(timeheap);
    for(bl = blockers; bl; bl = nbl) {
	nbl = bl->n;
	if(regfd(bl))
	    resume(bl->th, -1);
    }
    while(blockers != NULL) {
	now = time(NULL);
	if(timeheap.d == 0)
	    toval = -1;
	else if(timeheap.b[0].to > now)
	    toval = (timeheap.b[0].to - 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)) {
		    if(bl->id < 0) {
			resume(bl->th, ev);
		    } else {
			bl->rev = ev;
			resume(bl->th, bl->id);
		    }
		}
	    }
	}
	now = time(NULL);
	while((timeheap.d > 0) && (timeheap.b[0].to <= now)) {
	    if(bl->id < 0) {
		resume(timeheap.b[0].bl->th, 0);
	    } else {
		bl->rev = 0;
		resume(bl->th, bl->id);
	    }
	}
    }
    for(bl = blockers; bl; bl = bl->n)
	remfd(bl);
    buffree(timeheap);
    close(epfd);
    epfd = -1;
    return(exitstatus);
}

void exitioloop(int status)
{
    exitstatus = status;
}
Commit	Line	Data
	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>
	20	#include <unistd.h>
	21	#include <time.h>
	22	#include <fcntl.h>
	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, rev, id;
	41	int thpos;
	42	time_t to;
	43	struct muth *th;
	44	};
	45
	46	struct timeentry {
	47	time_t to;
	48	struct blocker *bl;
	49	};
	50
	51	static int epfd = -1, fdln = 0;
	52	static int exitstatus;
	53	static struct blocker **fdlist;
	54	static typedbuf(struct timeentry) timeheap;
	55
	56	static int regfd(struct blocker *bl)
	57	{
	58	struct blocker *o;
	59	struct epoll_event evd;
	60
	61	memset(&evd, 0, sizeof(evd));
	62	evd.events = 0;
	63	if(bl->ev & EV_READ)
	64	evd.events \|= EPOLLIN;
	65	if(bl->ev & EV_WRITE)
	66	evd.events \|= EPOLLOUT;
	67	evd.data.fd = bl->fd;
	68	if(bl->fd >= fdln) {
	69	if(fdlist) {
	70	fdlist = srealloc(fdlist, sizeof(fdlist) (bl->fd + 1));
	71	memset(fdlist + fdln, 0, sizeof(fdlist) (bl->fd + 1 - fdln));
	72	fdln = bl->fd + 1;
	73	} else {
	74	fdlist = szmalloc(sizeof(fdlist) (fdln = (bl->fd + 1)));
	75	}
	76	}
	77	if(fdlist[bl->fd] == NULL) {
	78	if(epoll_ctl(epfd, EPOLL_CTL_ADD, bl->fd, &evd)) {
	79	/* XXX?! Whatever to do, really? */
	80	flog(LOG_ERR, "epoll_add on fd %i: %s", bl->fd, strerror(errno));
	81	return(-1);
	82	}
	83	} else {
	84	for(o = fdlist[bl->fd]; o; o = o->n2) {
	85	if(o->ev & EV_READ)
	86	evd.events \|= EPOLLIN;
	87	if(o->ev & EV_WRITE)
	88	evd.events \|= EPOLLOUT;
	89	}
	90	if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) {
	91	/* XXX?! Whatever to do, really? */
	92	flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno));
	93	return(-1);
	94	}
	95	}
	96	bl->n2 = fdlist[bl->fd];
	97	bl->p2 = NULL;
	98	if(fdlist[bl->fd] != NULL)
	99	fdlist[bl->fd]->p2 = bl;
	100	fdlist[bl->fd] = bl;
	101	bl->reg = 1;
	102	return(0);
	103	}
	104
	105	static void remfd(struct blocker *bl)
	106	{
	107	struct blocker *o;
	108	struct epoll_event evd;
	109
	110	if(!bl->reg)
	111	return;
	112	if(bl->n2)
	113	bl->n2->p2 = bl->p2;
	114	if(bl->p2)
	115	bl->p2->n2 = bl->n2;
	116	if(bl == fdlist[bl->fd])
	117	fdlist[bl->fd] = bl->n2;
	118	if(fdlist[bl->fd] == NULL) {
	119	if(epoll_ctl(epfd, EPOLL_CTL_DEL, bl->fd, NULL))
	120	flog(LOG_ERR, "epoll_del on fd %i: %s", bl->fd, strerror(errno));
	121	} else {
	122	memset(&evd, 0, sizeof(evd));
	123	evd.events = 0;
	124	evd.data.fd = bl->fd;
	125	for(o = fdlist[bl->fd]; o; o = o->n2) {
	126	if(o->ev & EV_READ)
	127	evd.events \|= EPOLLIN;
	128	if(o->ev & EV_WRITE)
	129	evd.events \|= EPOLLOUT;
	130	}
	131	if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) {
	132	/* XXX?! Whatever to do, really? */
	133	flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno));
	134	}
	135	}
	136	bl->reg = 0;
	137	}
	138
	139	static void thraise(struct timeentry ent, int n)
	140	{
	141	int p;
	142
	143	while(n > 0) {
	144	p = (n - 1) >> 1;
	145	if(timeheap.b[p].to <= ent.to)
	146	break;
	147	timeheap.b[n] = timeheap.b[p];
	148	timeheap.b[n].bl->thpos = n;
	149	n = p;
	150	}
	151	timeheap.b[n] = ent;
	152	ent.bl->thpos = n;
	153	}
	154
	155	static void thlower(struct timeentry ent, int n)
	156	{
	157	int c;
	158
	159	while(1) {
	160	c = (n << 1) + 1;
	161	if(c >= timeheap.d)
	162	break;
	163	if((c + 1 < timeheap.d) && (timeheap.b[c + 1].to < timeheap.b[c].to))
	164	c = c + 1;
	165	if(timeheap.b[c].to > ent.to)
	166	break;
	167	timeheap.b[n] = timeheap.b[c];
	168	timeheap.b[n].bl->thpos = n;
	169	n = c;
	170	}
	171	timeheap.b[n] = ent;
	172	ent.bl->thpos = n;
	173	}
	174
	175	static void addtimeout(struct blocker *bl, time_t to)
	176	{
	177	sizebuf(timeheap, ++timeheap.d);
	178	thraise((struct timeentry){.to = to, .bl = bl}, timeheap.d - 1);
	179	}
	180
	181	static void deltimeout(struct blocker *bl)
	182	{
	183	struct timeentry ent;
	184	int n;
	185
	186	if(bl->thpos == timeheap.d - 1) {
	187	timeheap.d--;
	188	return;
	189	}
	190	n = bl->thpos;
	191	ent = timeheap.b[--timeheap.d];
	192	if((n > 0) && (timeheap.b[(n - 1) >> 1].to > ent.to))
	193	thraise(ent, n);
	194	else
	195	thlower(ent, n);
	196	}
	197
	198	static int addblock(struct blocker *bl)
	199	{
	200	if((epfd >= 0) && regfd(bl))
	201	return(-1);
	202	bl->n = blockers;
	203	if(blockers)
	204	blockers->p = bl;
	205	blockers = bl;
	206	if(bl->to > 0)
	207	addtimeout(bl, bl->to);
	208	return(0);
	209	}
	210
	211	static void remblock(struct blocker *bl)
	212	{
	213	if(bl->to > 0)
	214	deltimeout(bl);
	215	if(bl->n)
	216	bl->n->p = bl->p;
	217	if(bl->p)
	218	bl->p->n = bl->n;
	219	if(blockers == bl)
	220	blockers = bl->n;
	221	remfd(bl);
	222	}
	223
	224	struct selected mblock(time_t to, int n, struct selected *spec)
	225	{
	226	int i, id;
	227	struct blocker bls[n];
	228
	229	to = (to > 0)?(time(NULL) + to):0;
	230	for(i = 0; i < n; i++) {
	231	bls[i] = (struct blocker) {
	232	.fd = spec[i].fd,
	233	.ev = spec[i].ev,
	234	.id = i,
	235	.to = to,
	236	.th = current,
	237	};
	238	if(addblock(&bls[i])) {
	239	for(i--; i >= 0; i--)
	240	remblock(&bls[i]);
	241	return((struct selected){.fd = -1, .ev = -1});
	242	}
	243	}
	244	id = yield();
	245	for(i = 0; i < n; i++)
	246	remblock(&bls[i]);
	247	if(id < 0)
	248	return((struct selected){.fd = -1, .ev = -1});
	249	return((struct selected){.fd = bls[id].fd, .ev = bls[id].rev});
	250	}
	251
	252	int block(int fd, int ev, time_t to)
	253	{
	254	struct blocker bl;
	255	int rv;
	256
	257	bl = (struct blocker) {
	258	.fd = fd,
	259	.ev = ev,
	260	.id = -1,
	261	.to = (to > 0)?(time(NULL) + to):0,
	262	.th = current,
	263	};
	264	if(addblock(&bl))
	265	return(-1);
	266	rv = yield();
	267	remblock(&bl);
	268	return(rv);
	269	}
	270
	271	int ioloop(void)
	272	{
	273	struct blocker bl, nbl;
	274	struct epoll_event evr[16];
	275	int i, fd, nev, ev, toval;
	276	time_t now;
	277
	278	exitstatus = 0;
	279	epfd = epoll_create(128);
	280	fcntl(epfd, F_SETFD, FD_CLOEXEC);
	281	bufinit(timeheap);
	282	for(bl = blockers; bl; bl = nbl) {
	283	nbl = bl->n;
	284	if(regfd(bl))
	285	resume(bl->th, -1);
	286	}
	287	while(blockers != NULL) {
	288	now = time(NULL);
	289	if(timeheap.d == 0)
	290	toval = -1;
	291	else if(timeheap.b[0].to > now)
	292	toval = (timeheap.b[0].to - now) * 1000;
	293	else
	294	toval = 1000;
	295	if(exitstatus)
	296	break;
	297	nev = epoll_wait(epfd, evr, sizeof(evr) / sizeof(*evr), toval);
	298	if(nev < 0) {
	299	if(errno != EINTR) {
	300	flog(LOG_CRIT, "ioloop: epoll_wait errored out: %s", strerror(errno));
	301	/* To avoid CPU hogging in case it's bad, which it
	302	* probably is. */
	303	sleep(1);
	304	}
	305	continue;
	306	}
	307	for(i = 0; i < nev; i++) {
	308	fd = evr[i].data.fd;
	309	ev = 0;
	310	if(evr[i].events & EPOLLIN)
	311	ev \|= EV_READ;
	312	if(evr[i].events & EPOLLOUT)
	313	ev \|= EV_WRITE;
	314	if(evr[i].events & ~(EPOLLIN \| EPOLLOUT))
	315	ev = -1;
	316	for(bl = fdlist[fd]; bl; bl = nbl) {
	317	nbl = bl->n2;
	318	if((ev < 0) \|\| (ev & bl->ev)) {
	319	if(bl->id < 0) {
	320	resume(bl->th, ev);
	321	} else {
	322	bl->rev = ev;
	323	resume(bl->th, bl->id);
	324	}
	325	}
	326	}
	327	}
	328	now = time(NULL);
	329	while((timeheap.d > 0) && (timeheap.b[0].to <= now)) {
	330	if(bl->id < 0) {
	331	resume(timeheap.b[0].bl->th, 0);
	332	} else {
	333	bl->rev = 0;
	334	resume(bl->th, bl->id);
	335	}
	336	}
	337	}
	338	for(bl = blockers; bl; bl = bl->n)
	339	remfd(bl);
	340	buffree(timeheap);
	341	close(epfd);
	342	epfd = -1;
	343	return(exitstatus);
	344	}
	345
	346	void exitioloop(int status)
	347	{
	348	exitstatus = status;
	349	}