Merge branch 'master' of git.dolda2000.com:/srv/git/r/ashd
[ashd.git] / lib / mtio-epoll.c
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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>
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20#include <unistd.h>
21#include <time.h>
be078ac9 22#include <fcntl.h>
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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
35static struct blocker *blockers;
36
37struct 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
45static int epfd = -1, fdln = 0;
46static struct blocker **fdlist;
47
48static int regfd(struct blocker *bl)
49{
50 struct blocker *o;
51 struct epoll_event evd;
52
53 memset(&evd, 0, sizeof(evd));
54 evd.events = 0;
55 if(bl->ev & EV_READ)
56 evd.events |= EPOLLIN;
57 if(bl->ev & EV_WRITE)
58 evd.events |= EPOLLOUT;
59 evd.data.fd = bl->fd;
60 if(bl->fd >= fdln) {
61 if(fdlist) {
62 fdlist = srealloc(fdlist, sizeof(*fdlist) * (bl->fd + 1));
63 memset(fdlist + fdln, 0, sizeof(*fdlist) * (bl->fd + 1 - fdln));
64 fdln = bl->fd + 1;
65 } else {
66 fdlist = szmalloc(sizeof(*fdlist) * (fdln = (bl->fd + 1)));
67 }
68 }
69 if(fdlist[bl->fd] == NULL) {
70 if(epoll_ctl(epfd, EPOLL_CTL_ADD, bl->fd, &evd)) {
71 /* XXX?! Whatever to do, really? */
72 flog(LOG_ERR, "epoll_add on fd %i: %s", bl->fd, strerror(errno));
73 return(-1);
74 }
75 } else {
76 for(o = fdlist[bl->fd]; o; o = o->n2) {
77 if(o->ev & EV_READ)
78 evd.events |= EPOLLIN;
79 if(o->ev & EV_WRITE)
80 evd.events |= EPOLLOUT;
81 }
82 if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) {
83 /* XXX?! Whatever to do, really? */
84 flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno));
85 return(-1);
86 }
87 }
88 bl->n2 = fdlist[bl->fd];
89 bl->p2 = NULL;
90 if(fdlist[bl->fd] != NULL)
91 fdlist[bl->fd]->p2 = bl;
92 fdlist[bl->fd] = bl;
93 bl->reg = 1;
94 return(0);
95}
96
97static void remfd(struct blocker *bl)
98{
99 struct blocker *o;
100 struct epoll_event evd;
101
102 if(!bl->reg)
103 return;
104 if(bl->n2)
105 bl->n2->p2 = bl->p2;
106 if(bl->p2)
107 bl->p2->n2 = bl->n2;
108 if(bl == fdlist[bl->fd])
109 fdlist[bl->fd] = bl->n2;
110 if(fdlist[bl->fd] == NULL) {
111 if(epoll_ctl(epfd, EPOLL_CTL_DEL, bl->fd, NULL))
112 flog(LOG_ERR, "epoll_del on fd %i: %s", bl->fd, strerror(errno));
113 } else {
114 memset(&evd, 0, sizeof(evd));
115 evd.events = 0;
116 evd.data.fd = bl->fd;
117 for(o = fdlist[bl->fd]; o; o = o->n2) {
118 if(o->ev & EV_READ)
119 evd.events |= EPOLLIN;
120 if(o->ev & EV_WRITE)
121 evd.events |= EPOLLOUT;
122 }
123 if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) {
124 /* XXX?! Whatever to do, really? */
125 flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno));
126 }
127 }
128}
129
130int block(int fd, int ev, time_t to)
131{
132 struct blocker *bl;
133 int rv;
134
135 omalloc(bl);
136 bl->fd = fd;
137 bl->ev = ev;
138 if(to > 0)
139 bl->to = time(NULL) + to;
140 bl->th = current;
141 if((epfd >= 0) && regfd(bl)) {
142 free(bl);
143 return(-1);
144 }
145 bl->n = blockers;
146 if(blockers)
147 blockers->p = bl;
148 blockers = bl;
149 rv = yield();
150 if(bl->n)
151 bl->n->p = bl->p;
152 if(bl->p)
153 bl->p->n = bl->n;
154 if(bl == blockers)
155 blockers = bl->n;
156 remfd(bl);
157 free(bl);
158 return(rv);
159}
160
161void ioloop(void)
162{
163 struct blocker *bl, *nbl;
164 struct epoll_event evr[16];
165 int i, fd, nev, ev, toval;
166 time_t now, timeout;
167
168 epfd = epoll_create(128);
be078ac9 169 fcntl(epfd, F_SETFD, FD_CLOEXEC);
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170 for(bl = blockers; bl; bl = nbl) {
171 nbl = bl->n;
172 if(regfd(bl))
173 resume(bl->th, -1);
174 }
175 while(blockers != NULL) {
176 timeout = 0;
177 for(bl = blockers; bl; bl = bl->n) {
178 if((bl->to != 0) && ((timeout == 0) || (timeout > bl->to)))
179 timeout = bl->to;
180 }
181 now = time(NULL);
182 if(timeout == 0)
183 toval = -1;
184 else if(timeout > now)
185 toval = (timeout - now) * 1000;
186 else
187 toval = 1000;
188 nev = epoll_wait(epfd, evr, sizeof(evr) / sizeof(*evr), toval);
189 if(nev < 0) {
190 if(errno != EINTR) {
f43decce 191 flog(LOG_CRIT, "ioloop: epoll_wait errored out: %s", strerror(errno));
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192 /* To avoid CPU hogging in case it's bad, which it
193 * probably is. */
194 sleep(1);
195 }
196 continue;
197 }
198 for(i = 0; i < nev; i++) {
199 fd = evr[i].data.fd;
200 ev = 0;
201 if(evr[i].events & EPOLLIN)
202 ev |= EV_READ;
203 if(evr[i].events & EPOLLOUT)
204 ev |= EV_WRITE;
205 if(evr[i].events & ~(EPOLLIN | EPOLLOUT))
206 ev = -1;
207 for(bl = fdlist[fd]; bl; bl = nbl) {
208 nbl = bl->n2;
209 if((ev < 0) || (ev & bl->ev))
210 resume(bl->th, ev);
211 }
212 }
213 now = time(NULL);
214 for(bl = blockers; bl; bl = nbl) {
215 nbl = bl->n;
216 if((bl->to != 0) && (bl->to <= now))
217 resume(bl->th, 0);
218 }
219 }
220 close(epfd);
221 epfd = -1;
222}