| 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 <string.h> |
| 21 | #include <sys/epoll.h> |
| 22 | #include <errno.h> |
| 23 | |
| 24 | #ifdef HAVE_CONFIG_H |
| 25 | #include <config.h> |
| 26 | #endif |
| 27 | #include <log.h> |
| 28 | #include <utils.h> |
| 29 | #include <mt.h> |
| 30 | #include <mtio.h> |
| 31 | |
| 32 | static struct blocker *blockers; |
| 33 | |
| 34 | struct blocker { |
| 35 | struct blocker *n, *p, *n2, *p2; |
| 36 | int fd, reg; |
| 37 | int ev; |
| 38 | time_t to; |
| 39 | struct muth *th; |
| 40 | }; |
| 41 | |
| 42 | static int epfd = -1, fdln = 0; |
| 43 | static struct blocker **fdlist; |
| 44 | |
| 45 | static int regfd(struct blocker *bl) |
| 46 | { |
| 47 | struct blocker *o; |
| 48 | struct epoll_event evd; |
| 49 | |
| 50 | memset(&evd, 0, sizeof(evd)); |
| 51 | evd.events = 0; |
| 52 | if(bl->ev & EV_READ) |
| 53 | evd.events |= EPOLLIN; |
| 54 | if(bl->ev & EV_WRITE) |
| 55 | evd.events |= EPOLLOUT; |
| 56 | evd.data.fd = bl->fd; |
| 57 | if(bl->fd >= fdln) { |
| 58 | if(fdlist) { |
| 59 | fdlist = srealloc(fdlist, sizeof(*fdlist) * (bl->fd + 1)); |
| 60 | memset(fdlist + fdln, 0, sizeof(*fdlist) * (bl->fd + 1 - fdln)); |
| 61 | fdln = bl->fd + 1; |
| 62 | } else { |
| 63 | fdlist = szmalloc(sizeof(*fdlist) * (fdln = (bl->fd + 1))); |
| 64 | } |
| 65 | } |
| 66 | if(fdlist[bl->fd] == NULL) { |
| 67 | if(epoll_ctl(epfd, EPOLL_CTL_ADD, bl->fd, &evd)) { |
| 68 | /* XXX?! Whatever to do, really? */ |
| 69 | flog(LOG_ERR, "epoll_add on fd %i: %s", bl->fd, strerror(errno)); |
| 70 | return(-1); |
| 71 | } |
| 72 | } else { |
| 73 | for(o = fdlist[bl->fd]; o; o = o->n2) { |
| 74 | if(o->ev & EV_READ) |
| 75 | evd.events |= EPOLLIN; |
| 76 | if(o->ev & EV_WRITE) |
| 77 | evd.events |= EPOLLOUT; |
| 78 | } |
| 79 | if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) { |
| 80 | /* XXX?! Whatever to do, really? */ |
| 81 | flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno)); |
| 82 | return(-1); |
| 83 | } |
| 84 | } |
| 85 | bl->n2 = fdlist[bl->fd]; |
| 86 | bl->p2 = NULL; |
| 87 | if(fdlist[bl->fd] != NULL) |
| 88 | fdlist[bl->fd]->p2 = bl; |
| 89 | fdlist[bl->fd] = bl; |
| 90 | bl->reg = 1; |
| 91 | return(0); |
| 92 | } |
| 93 | |
| 94 | static void remfd(struct blocker *bl) |
| 95 | { |
| 96 | struct blocker *o; |
| 97 | struct epoll_event evd; |
| 98 | |
| 99 | if(!bl->reg) |
| 100 | return; |
| 101 | if(bl->n2) |
| 102 | bl->n2->p2 = bl->p2; |
| 103 | if(bl->p2) |
| 104 | bl->p2->n2 = bl->n2; |
| 105 | if(bl == fdlist[bl->fd]) |
| 106 | fdlist[bl->fd] = bl->n2; |
| 107 | if(fdlist[bl->fd] == NULL) { |
| 108 | if(epoll_ctl(epfd, EPOLL_CTL_DEL, bl->fd, NULL)) |
| 109 | flog(LOG_ERR, "epoll_del on fd %i: %s", bl->fd, strerror(errno)); |
| 110 | } else { |
| 111 | memset(&evd, 0, sizeof(evd)); |
| 112 | evd.events = 0; |
| 113 | evd.data.fd = bl->fd; |
| 114 | for(o = fdlist[bl->fd]; o; o = o->n2) { |
| 115 | if(o->ev & EV_READ) |
| 116 | evd.events |= EPOLLIN; |
| 117 | if(o->ev & EV_WRITE) |
| 118 | evd.events |= EPOLLOUT; |
| 119 | } |
| 120 | if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) { |
| 121 | /* XXX?! Whatever to do, really? */ |
| 122 | flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno)); |
| 123 | } |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | int block(int fd, int ev, time_t to) |
| 128 | { |
| 129 | struct blocker *bl; |
| 130 | int rv; |
| 131 | |
| 132 | omalloc(bl); |
| 133 | bl->fd = fd; |
| 134 | bl->ev = ev; |
| 135 | if(to > 0) |
| 136 | bl->to = time(NULL) + to; |
| 137 | bl->th = current; |
| 138 | if((epfd >= 0) && regfd(bl)) { |
| 139 | free(bl); |
| 140 | return(-1); |
| 141 | } |
| 142 | bl->n = blockers; |
| 143 | if(blockers) |
| 144 | blockers->p = bl; |
| 145 | blockers = bl; |
| 146 | rv = yield(); |
| 147 | if(bl->n) |
| 148 | bl->n->p = bl->p; |
| 149 | if(bl->p) |
| 150 | bl->p->n = bl->n; |
| 151 | if(bl == blockers) |
| 152 | blockers = bl->n; |
| 153 | remfd(bl); |
| 154 | free(bl); |
| 155 | return(rv); |
| 156 | } |
| 157 | |
| 158 | void ioloop(void) |
| 159 | { |
| 160 | struct blocker *bl, *nbl; |
| 161 | struct epoll_event evr[16]; |
| 162 | int i, fd, nev, ev, toval; |
| 163 | time_t now, timeout; |
| 164 | |
| 165 | epfd = epoll_create(128); |
| 166 | for(bl = blockers; bl; bl = nbl) { |
| 167 | nbl = bl->n; |
| 168 | if(regfd(bl)) |
| 169 | resume(bl->th, -1); |
| 170 | } |
| 171 | while(blockers != NULL) { |
| 172 | timeout = 0; |
| 173 | for(bl = blockers; bl; bl = bl->n) { |
| 174 | if((bl->to != 0) && ((timeout == 0) || (timeout > bl->to))) |
| 175 | timeout = bl->to; |
| 176 | } |
| 177 | now = time(NULL); |
| 178 | if(timeout == 0) |
| 179 | toval = -1; |
| 180 | else if(timeout > now) |
| 181 | toval = (timeout - now) * 1000; |
| 182 | else |
| 183 | toval = 1000; |
| 184 | nev = epoll_wait(epfd, evr, sizeof(evr) / sizeof(*evr), toval); |
| 185 | if(nev < 0) { |
| 186 | if(errno != EINTR) { |
| 187 | flog(LOG_CRIT, "ioloop: select errored out: %s", strerror(errno)); |
| 188 | /* To avoid CPU hogging in case it's bad, which it |
| 189 | * probably is. */ |
| 190 | sleep(1); |
| 191 | } |
| 192 | continue; |
| 193 | } |
| 194 | for(i = 0; i < nev; i++) { |
| 195 | fd = evr[i].data.fd; |
| 196 | ev = 0; |
| 197 | if(evr[i].events & EPOLLIN) |
| 198 | ev |= EV_READ; |
| 199 | if(evr[i].events & EPOLLOUT) |
| 200 | ev |= EV_WRITE; |
| 201 | if(evr[i].events & ~(EPOLLIN | EPOLLOUT)) |
| 202 | ev = -1; |
| 203 | for(bl = fdlist[fd]; bl; bl = nbl) { |
| 204 | nbl = bl->n2; |
| 205 | if((ev < 0) || (ev & bl->ev)) |
| 206 | resume(bl->th, ev); |
| 207 | } |
| 208 | } |
| 209 | now = time(NULL); |
| 210 | for(bl = blockers; bl; bl = nbl) { |
| 211 | nbl = bl->n; |
| 212 | if((bl->to != 0) && (bl->to <= now)) |
| 213 | resume(bl->th, 0); |
| 214 | } |
| 215 | } |
| 216 | close(epfd); |
| 217 | epfd = -1; |
| 218 | } |