[ashd.git] / lib / mtio.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 <string.h>
#include <time.h>
#include <errno.h>
#include <sys/select.h>

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

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

static struct blocker *blockers;

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;
    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;
    return(rv);
}

void ioloop(void)
{
    int ret;
    fd_set rfds, wfds, efds;
    struct blocker *bl, *nbl;
    struct timeval toval;
    time_t now, timeout;
    int maxfd;
    int ev;
    
    while(blockers != NULL) {
	FD_ZERO(&rfds);
	FD_ZERO(&wfds);
	FD_ZERO(&efds);
	maxfd = 0;
	now = time(NULL);
	timeout = 0;
	for(bl = blockers; bl; bl = bl->n) {
	    if(bl->ev & EV_READ)
		FD_SET(bl->fd, &rfds);
	    if(bl->ev & EV_WRITE)
		FD_SET(bl->fd, &wfds);
	    FD_SET(bl->fd, &efds);
	    if(bl->fd > maxfd)
		maxfd = bl->fd;
	    if((bl->to != 0) && ((timeout == 0) || (timeout > bl->to)))
		timeout = bl->to;
	}
	toval.tv_sec = timeout - now;
	toval.tv_usec = 0;
	ret = select(maxfd + 1, &rfds, &wfds, &efds, timeout?(&toval):NULL);
	if(ret < 0) {
	    if(errno != EINTR) {
		flog(LOG_CRIT, "ioloop: select errored out: %s", strerror(errno));
		/* To avoid CPU hogging in case it's bad, which it
		 * probably is. */
		sleep(1);
	    }
	}
	now = time(NULL);
	for(bl = blockers; bl; bl = nbl) {
	    nbl = bl->n;
	    ev = 0;
	    if(FD_ISSET(bl->fd, &rfds))
		ev |= EV_READ;
	    if(FD_ISSET(bl->fd, &wfds))
		ev |= EV_WRITE;
	    if(FD_ISSET(bl->fd, &efds))
		ev = -1;
	    if((ev < 0) || (ev & bl->ev))
		resume(bl->th, ev);
	    else if((bl->to != 0) && (bl->to <= now))
		resume(bl->th, 0);
	}
    }
}
Commit	Line	Data
83723896 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>
	20	#include <unistd.h>
	21	#include <string.h>
	22	#include <time.h>
	23	#include <errno.h>
	24	#include <sys/select.h>
	25
	26	#ifdef HAVE_CONFIG_H
	27	#include <config.h>
	28	#endif
	29	#include <log.h>
	30	#include <utils.h>
	31	#include <mt.h>
	32	#include <mtio.h>
	33
	34	struct blocker {
	35	struct blocker n, p;
	36	int fd;
	37	int ev;
	38	time_t to;
	39	struct muth *th;
	40	};
	41
	42	static struct blocker *blockers;
	43
	44	int block(int fd, int ev, time_t to)
	45	{
	46	struct blocker *bl;
	47	int rv;
	48
	49	omalloc(bl);
	50	bl->fd = fd;
	51	bl->ev = ev;
	52	if(to > 0)
	53	bl->to = time(NULL) + to;
	54	bl->th = current;
	55	bl->n = blockers;
	56	if(blockers)
	57	blockers->p = bl;
	58	blockers = bl;
	59	rv = yield();
	60	if(bl->n)
	61	bl->n->p = bl->p;
	62	if(bl->p)
	63	bl->p->n = bl->n;
	64	if(bl == blockers)
65	blockers = bl->n;
66	return(rv);
67	}
68
69	void ioloop(void)
70	{
71	int ret;
72	fd_set rfds, wfds, efds;
73	struct blocker bl, nbl;
74	struct timeval toval;
75	time_t now, timeout;
76	int maxfd;
77	int ev;
78
79	while(blockers != NULL) {
80	FD_ZERO(&rfds);
81	FD_ZERO(&wfds);
82	FD_ZERO(&efds);
83	maxfd = 0;
84	now = time(NULL);
85	timeout = 0;
86	for(bl = blockers; bl; bl = bl->n) {
87	if(bl->ev & EV_READ)
88	FD_SET(bl->fd, &rfds);
89	if(bl->ev & EV_WRITE)
90	FD_SET(bl->fd, &wfds);
91	FD_SET(bl->fd, &efds);
92	if(bl->fd > maxfd)
93	maxfd = bl->fd;
94	if((bl->to != 0) && ((timeout == 0) \|\| (timeout > bl->to)))
95	timeout = bl->to;
96	}
97	toval.tv_sec = timeout - now;
98	toval.tv_usec = 0;
99	ret = select(maxfd + 1, &rfds, &wfds, &efds, timeout?(&toval):NULL);
100	if(ret < 0) {
101	if(errno != EINTR) {
102	flog(LOG_CRIT, "ioloop: select errored out: %s", strerror(errno));
103	/* To avoid CPU hogging in case it's bad, which it
104	* probably is. */
105	sleep(1);
106	}
107	}
108	now = time(NULL);
109	for(bl = blockers; bl; bl = nbl) {
110	nbl = bl->n;
111	ev = 0;
112	if(FD_ISSET(bl->fd, &rfds))
113	ev \|= EV_READ;
114	if(FD_ISSET(bl->fd, &wfds))
115	ev \|= EV_WRITE;
116	if(FD_ISSET(bl->fd, &efds))
117	ev = -1;
3dc69b45	118	if((ev < 0) \|\| (ev & bl->ev))
83723896 FT	119	resume(bl->th, ev);
	120	else if((bl->to != 0) && (bl->to <= now))
	121	resume(bl->th, 0);
	122	}
	123	}
	124	}