[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;
};

static int epfd = -1, fdln = 0;
static int exitstatus;
static struct blocker **fdlist;
static typedbuf(struct blocker *) 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 blocker *bl, int n)
{
    int p;
    
    while(n > 0) {
	p = (n - 1) >> 1;
	if(timeheap.b[p]->to <= bl->to)
	    break;
	timeheap.b[n] = timeheap.b[p];
	timeheap.b[n]->thpos = n;
	n = p;
    }
    timeheap.b[n] = bl;
    bl->thpos = n;
}

static void thlower(struct blocker *bl, 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 > bl->to)
	    break;
	timeheap.b[n] = timeheap.b[c];
	timeheap.b[n]->thpos = n;
	n = c;
    }
    timeheap.b[n] = bl;
    bl->thpos = n;
}

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

static void deltimeout(struct blocker *bl)
{
    int n;
    
    if(bl->thpos == timeheap.d - 1) {
	timeheap.d--;
	return;
    }
    n = bl->thpos;
    bl = timeheap.b[--timeheap.d];
    if((n > 0) && (timeheap.b[(n - 1) >> 1]->to > bl->to))
	thraise(bl, n);
    else
	thlower(bl, 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) && ((bl = timeheap.b[0])->to <= now)) {
	    if(bl->id < 0) {
		resume(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
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;
205ee933	40	int ev, rev, id;
589987f8	41	int thpos;
a6cda4dd FT	42	time_t to;
	43	struct muth *th;
	44	};
	45
	46	static int epfd = -1, fdln = 0;
9d32586e	47	static int exitstatus;
a6cda4dd	48	static struct blocker **fdlist;
bb073004	49	static typedbuf(struct blocker *) timeheap;
a6cda4dd FT	50
	51	static int regfd(struct blocker *bl)
	52	{
	53	struct blocker *o;
	54	struct epoll_event evd;
	55
	56	memset(&evd, 0, sizeof(evd));
	57	evd.events = 0;
	58	if(bl->ev & EV_READ)
	59	evd.events \|= EPOLLIN;
	60	if(bl->ev & EV_WRITE)
	61	evd.events \|= EPOLLOUT;
	62	evd.data.fd = bl->fd;
	63	if(bl->fd >= fdln) {
	64	if(fdlist) {
	65	fdlist = srealloc(fdlist, sizeof(fdlist) (bl->fd + 1));
	66	memset(fdlist + fdln, 0, sizeof(fdlist) (bl->fd + 1 - fdln));
	67	fdln = bl->fd + 1;
	68	} else {
	69	fdlist = szmalloc(sizeof(fdlist) (fdln = (bl->fd + 1)));
	70	}
	71	}
	72	if(fdlist[bl->fd] == NULL) {
	73	if(epoll_ctl(epfd, EPOLL_CTL_ADD, bl->fd, &evd)) {
	74	/* XXX?! Whatever to do, really? */
	75	flog(LOG_ERR, "epoll_add on fd %i: %s", bl->fd, strerror(errno));
	76	return(-1);
	77	}
	78	} else {
	79	for(o = fdlist[bl->fd]; o; o = o->n2) {
	80	if(o->ev & EV_READ)
	81	evd.events \|= EPOLLIN;
	82	if(o->ev & EV_WRITE)
	83	evd.events \|= EPOLLOUT;
	84	}
	85	if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) {
	86	/* XXX?! Whatever to do, really? */
	87	flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno));
	88	return(-1);
	89	}
	90	}
	91	bl->n2 = fdlist[bl->fd];
	92	bl->p2 = NULL;
	93	if(fdlist[bl->fd] != NULL)
	94	fdlist[bl->fd]->p2 = bl;
	95	fdlist[bl->fd] = bl;
	96	bl->reg = 1;
	97	return(0);
	98	}
	99
	100	static void remfd(struct blocker *bl)
	101	{
	102	struct blocker *o;
	103	struct epoll_event evd;
	104
	105	if(!bl->reg)
	106	return;
	107	if(bl->n2)
	108	bl->n2->p2 = bl->p2;
	109	if(bl->p2)
	110	bl->p2->n2 = bl->n2;
	111	if(bl == fdlist[bl->fd])
	112	fdlist[bl->fd] = bl->n2;
	113	if(fdlist[bl->fd] == NULL) {
114	if(epoll_ctl(epfd, EPOLL_CTL_DEL, bl->fd, NULL))
115	flog(LOG_ERR, "epoll_del on fd %i: %s", bl->fd, strerror(errno));
116	} else {
117	memset(&evd, 0, sizeof(evd));
118	evd.events = 0;
119	evd.data.fd = bl->fd;
120	for(o = fdlist[bl->fd]; o; o = o->n2) {
121	if(o->ev & EV_READ)
122	evd.events \|= EPOLLIN;
123	if(o->ev & EV_WRITE)
124	evd.events \|= EPOLLOUT;
125	}
126	if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) {
127	/* XXX?! Whatever to do, really? */
128	flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno));
129	}
130	}
9d32586e	131	bl->reg = 0;
a6cda4dd FT	132	}
a6cda4dd FT	133
bb073004	134	static void thraise(struct blocker *bl, int n)
589987f8 FT	135	{
	136	int p;
	137
	138	while(n > 0) {
	139	p = (n - 1) >> 1;
bb073004	140	if(timeheap.b[p]->to <= bl->to)
589987f8 FT	141	break;
589987f8 FT	142	timeheap.b[n] = timeheap.b[p];
bb073004	143	timeheap.b[n]->thpos = n;
589987f8 FT	144	n = p;
589987f8 FT	145	}
bb073004 FT	146	timeheap.b[n] = bl;
bb073004 FT	147	bl->thpos = n;
589987f8 FT	148	}
589987f8 FT	149
bb073004	150	static void thlower(struct blocker *bl, int n)
589987f8 FT	151	{
	152	int c;
	153
	154	while(1) {
	155	c = (n << 1) + 1;
	156	if(c >= timeheap.d)
	157	break;
bb073004	158	if((c + 1 < timeheap.d) && (timeheap.b[c + 1]->to < timeheap.b[c]->to))
589987f8	159	c = c + 1;
bb073004	160	if(timeheap.b[c]->to > bl->to)
589987f8 FT	161	break;
589987f8 FT	162	timeheap.b[n] = timeheap.b[c];
bb073004	163	timeheap.b[n]->thpos = n;
589987f8 FT	164	n = c;
589987f8 FT	165	}
bb073004 FT	166	timeheap.b[n] = bl;
bb073004 FT	167	bl->thpos = n;
589987f8 FT	168	}
	169
	170	static void addtimeout(struct blocker *bl, time_t to)
	171	{
	172	sizebuf(timeheap, ++timeheap.d);
bb073004	173	thraise(bl, timeheap.d - 1);
589987f8 FT	174	}
	175
	176	static void deltimeout(struct blocker *bl)
	177	{
589987f8 FT	178	int n;
	179
	180	if(bl->thpos == timeheap.d - 1) {
	181	timeheap.d--;
	182	return;
	183	}
	184	n = bl->thpos;
bb073004 FT	185	bl = timeheap.b[--timeheap.d];
	186	if((n > 0) && (timeheap.b[(n - 1) >> 1]->to > bl->to))
	187	thraise(bl, n);
589987f8	188	else
bb073004	189	thlower(bl, n);
589987f8 FT	190	}
589987f8 FT	191
205ee933	192	static int addblock(struct blocker *bl)
a6cda4dd	193	{
205ee933	194	if((epfd >= 0) && regfd(bl))
a6cda4dd	195	return(-1);
a6cda4dd FT	196	bl->n = blockers;
	197	if(blockers)
	198	blockers->p = bl;
	199	blockers = bl;
bcad6b0c FT	200	if(bl->to > 0)
bcad6b0c FT	201	addtimeout(bl, bl->to);
205ee933 FT	202	return(0);
	203	}
	204
	205	static void remblock(struct blocker *bl)
	206	{
589987f8 FT	207	if(bl->to > 0)
589987f8 FT	208	deltimeout(bl);
a6cda4dd FT	209	if(bl->n)
	210	bl->n->p = bl->p;
	211	if(bl->p)
	212	bl->p->n = bl->n;
205ee933	213	if(blockers == bl)
a6cda4dd FT	214	blockers = bl->n;
a6cda4dd FT	215	remfd(bl);
205ee933 FT	216	}
	217
	218	struct selected mblock(time_t to, int n, struct selected *spec)
	219	{
	220	int i, id;
	221	struct blocker bls[n];
	222
	223	to = (to > 0)?(time(NULL) + to):0;
	224	for(i = 0; i < n; i++) {
	225	bls[i] = (struct blocker) {
	226	.fd = spec[i].fd,
	227	.ev = spec[i].ev,
	228	.id = i,
	229	.to = to,
	230	.th = current,
	231	};
	232	if(addblock(&bls[i])) {
4f5bec84	233	for(i--; i >= 0; i--)
205ee933 FT	234	remblock(&bls[i]);
	235	return((struct selected){.fd = -1, .ev = -1});
	236	}
	237	}
	238	id = yield();
	239	for(i = 0; i < n; i++)
	240	remblock(&bls[i]);
	241	if(id < 0)
	242	return((struct selected){.fd = -1, .ev = -1});
	243	return((struct selected){.fd = bls[id].fd, .ev = bls[id].rev});
	244	}
	245
	246	int block(int fd, int ev, time_t to)
	247	{
	248	struct blocker bl;
	249	int rv;
	250
	251	bl = (struct blocker) {
	252	.fd = fd,
	253	.ev = ev,
	254	.id = -1,
	255	.to = (to > 0)?(time(NULL) + to):0,
	256	.th = current,
	257	};
	258	if(addblock(&bl))
	259	return(-1);
	260	rv = yield();
	261	remblock(&bl);
a6cda4dd FT	262	return(rv);
	263	}
	264
9d32586e	265	int ioloop(void)
a6cda4dd FT	266	{
	267	struct blocker bl, nbl;
	268	struct epoll_event evr[16];
	269	int i, fd, nev, ev, toval;
589987f8	270	time_t now;
a6cda4dd	271
9d32586e	272	exitstatus = 0;
a6cda4dd	273	epfd = epoll_create(128);
be078ac9	274	fcntl(epfd, F_SETFD, FD_CLOEXEC);
589987f8	275	bufinit(timeheap);
a6cda4dd FT	276	for(bl = blockers; bl; bl = nbl) {
	277	nbl = bl->n;
	278	if(regfd(bl))
	279	resume(bl->th, -1);
	280	}
	281	while(blockers != NULL) {
a6cda4dd	282	now = time(NULL);
589987f8	283	if(timeheap.d == 0)
a6cda4dd	284	toval = -1;
bb073004 FT	285	else if(timeheap.b[0]->to > now)
bb073004 FT	286	toval = (timeheap.b[0]->to - now) * 1000;
a6cda4dd FT	287	else
a6cda4dd FT	288	toval = 1000;
9d32586e FT	289	if(exitstatus)
9d32586e FT	290	break;
a6cda4dd FT	291	nev = epoll_wait(epfd, evr, sizeof(evr) / sizeof(*evr), toval);
	292	if(nev < 0) {
	293	if(errno != EINTR) {
f43decce	294	flog(LOG_CRIT, "ioloop: epoll_wait errored out: %s", strerror(errno));
a6cda4dd FT	295	/* To avoid CPU hogging in case it's bad, which it
	296	* probably is. */
	297	sleep(1);
	298	}
	299	continue;
	300	}
	301	for(i = 0; i < nev; i++) {
	302	fd = evr[i].data.fd;
	303	ev = 0;
	304	if(evr[i].events & EPOLLIN)
	305	ev \|= EV_READ;
	306	if(evr[i].events & EPOLLOUT)
	307	ev \|= EV_WRITE;
	308	if(evr[i].events & ~(EPOLLIN \| EPOLLOUT))
	309	ev = -1;
	310	for(bl = fdlist[fd]; bl; bl = nbl) {
	311	nbl = bl->n2;
205ee933 FT	312	if((ev < 0) \|\| (ev & bl->ev)) {
	313	if(bl->id < 0) {
	314	resume(bl->th, ev);
	315	} else {
	316	bl->rev = ev;
	317	resume(bl->th, bl->id);
	318	}
	319	}
a6cda4dd FT	320	}
	321	}
	322	now = time(NULL);
bb073004	323	while((timeheap.d > 0) && ((bl = timeheap.b[0])->to <= now)) {
bcad6b0c	324	if(bl->id < 0) {
bb073004	325	resume(bl->th, 0);
bcad6b0c FT	326	} else {
	327	bl->rev = 0;
	328	resume(bl->th, bl->id);
205ee933	329	}
a6cda4dd FT	330	}
a6cda4dd FT	331	}
9d32586e FT	332	for(bl = blockers; bl; bl = bl->n)
9d32586e FT	333	remfd(bl);
589987f8	334	buffree(timeheap);
a6cda4dd FT	335	close(epfd);
a6cda4dd FT	336	epfd = -1;
9d32586e FT	337	return(exitstatus);
	338	}
	339
	340	void exitioloop(int status)
	341	{
	342	exitstatus = status;
a6cda4dd	343	}