python: Somewhat integrate async watchers with wsgidir currency.
[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;
205ee933 40 int ev, rev, id;
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41 time_t to;
42 struct muth *th;
43};
44
45static int epfd = -1, fdln = 0;
9d32586e 46static int exitstatus;
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47static struct blocker **fdlist;
48
49static 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
98static 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;
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130}
131
205ee933 132static int addblock(struct blocker *bl)
a6cda4dd 133{
205ee933 134 if((epfd >= 0) && regfd(bl))
a6cda4dd 135 return(-1);
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136 bl->n = blockers;
137 if(blockers)
138 blockers->p = bl;
139 blockers = bl;
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140 return(0);
141}
142
143static void remblock(struct blocker *bl)
144{
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145 if(bl->n)
146 bl->n->p = bl->p;
147 if(bl->p)
148 bl->p->n = bl->n;
205ee933 149 if(blockers == bl)
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150 blockers = bl->n;
151 remfd(bl);
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152}
153
154struct selected mblock(time_t to, int n, struct selected *spec)
155{
156 int i, id;
157 struct blocker bls[n];
158
159 to = (to > 0)?(time(NULL) + to):0;
160 for(i = 0; i < n; i++) {
161 bls[i] = (struct blocker) {
162 .fd = spec[i].fd,
163 .ev = spec[i].ev,
164 .id = i,
165 .to = to,
166 .th = current,
167 };
168 if(addblock(&bls[i])) {
4f5bec84 169 for(i--; i >= 0; i--)
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170 remblock(&bls[i]);
171 return((struct selected){.fd = -1, .ev = -1});
172 }
173 }
174 id = yield();
175 for(i = 0; i < n; i++)
176 remblock(&bls[i]);
177 if(id < 0)
178 return((struct selected){.fd = -1, .ev = -1});
179 return((struct selected){.fd = bls[id].fd, .ev = bls[id].rev});
180}
181
182int block(int fd, int ev, time_t to)
183{
184 struct blocker bl;
185 int rv;
186
187 bl = (struct blocker) {
188 .fd = fd,
189 .ev = ev,
190 .id = -1,
191 .to = (to > 0)?(time(NULL) + to):0,
192 .th = current,
193 };
194 if(addblock(&bl))
195 return(-1);
196 rv = yield();
197 remblock(&bl);
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198 return(rv);
199}
200
9d32586e 201int ioloop(void)
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202{
203 struct blocker *bl, *nbl;
204 struct epoll_event evr[16];
205 int i, fd, nev, ev, toval;
206 time_t now, timeout;
207
9d32586e 208 exitstatus = 0;
a6cda4dd 209 epfd = epoll_create(128);
be078ac9 210 fcntl(epfd, F_SETFD, FD_CLOEXEC);
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211 for(bl = blockers; bl; bl = nbl) {
212 nbl = bl->n;
213 if(regfd(bl))
214 resume(bl->th, -1);
215 }
216 while(blockers != NULL) {
217 timeout = 0;
218 for(bl = blockers; bl; bl = bl->n) {
219 if((bl->to != 0) && ((timeout == 0) || (timeout > bl->to)))
220 timeout = bl->to;
221 }
222 now = time(NULL);
223 if(timeout == 0)
224 toval = -1;
225 else if(timeout > now)
226 toval = (timeout - now) * 1000;
227 else
228 toval = 1000;
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229 if(exitstatus)
230 break;
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231 nev = epoll_wait(epfd, evr, sizeof(evr) / sizeof(*evr), toval);
232 if(nev < 0) {
233 if(errno != EINTR) {
f43decce 234 flog(LOG_CRIT, "ioloop: epoll_wait errored out: %s", strerror(errno));
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235 /* To avoid CPU hogging in case it's bad, which it
236 * probably is. */
237 sleep(1);
238 }
239 continue;
240 }
241 for(i = 0; i < nev; i++) {
242 fd = evr[i].data.fd;
243 ev = 0;
244 if(evr[i].events & EPOLLIN)
245 ev |= EV_READ;
246 if(evr[i].events & EPOLLOUT)
247 ev |= EV_WRITE;
248 if(evr[i].events & ~(EPOLLIN | EPOLLOUT))
249 ev = -1;
250 for(bl = fdlist[fd]; bl; bl = nbl) {
251 nbl = bl->n2;
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252 if((ev < 0) || (ev & bl->ev)) {
253 if(bl->id < 0) {
254 resume(bl->th, ev);
255 } else {
256 bl->rev = ev;
257 resume(bl->th, bl->id);
258 }
259 }
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260 }
261 }
262 now = time(NULL);
263 for(bl = blockers; bl; bl = nbl) {
264 nbl = bl->n;
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265 if((bl->to != 0) && (bl->to <= now)) {
266 if(bl->id < 0) {
267 resume(bl->th, 0);
268 } else {
269 bl->rev = 0;
270 resume(bl->th, bl->id);
271 }
272 }
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273 }
274 }
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275 for(bl = blockers; bl; bl = bl->n)
276 remfd(bl);
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277 close(epfd);
278 epfd = -1;
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279 return(exitstatus);
280}
281
282void exitioloop(int status)
283{
284 exitstatus = status;
a6cda4dd 285}