| 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 <time.h> |
| 22 | #include <unistd.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 | static struct blocker *blockers; |
| 35 | static int exitstatus; |
| 36 | |
| 37 | struct blocker { |
| 38 | struct blocker *n, *p; |
| 39 | int fd; |
| 40 | int ev; |
| 41 | time_t to; |
| 42 | struct muth *th; |
| 43 | }; |
| 44 | |
| 45 | int block(int fd, int ev, time_t to) |
| 46 | { |
| 47 | struct blocker *bl; |
| 48 | int rv; |
| 49 | |
| 50 | if(fd >= FD_SETSIZE) { |
| 51 | flog(LOG_ERR, "tried to use more file descriptors than select() can handle: fd %i", fd); |
| 52 | errno = EMFILE; |
| 53 | return(-1); |
| 54 | } |
| 55 | omalloc(bl); |
| 56 | bl->fd = fd; |
| 57 | bl->ev = ev; |
| 58 | if(to > 0) |
| 59 | bl->to = time(NULL) + to; |
| 60 | bl->th = current; |
| 61 | bl->n = blockers; |
| 62 | if(blockers) |
| 63 | blockers->p = bl; |
| 64 | blockers = bl; |
| 65 | rv = yield(); |
| 66 | if(bl->n) |
| 67 | bl->n->p = bl->p; |
| 68 | if(bl->p) |
| 69 | bl->p->n = bl->n; |
| 70 | if(bl == blockers) |
| 71 | blockers = bl->n; |
| 72 | free(bl); |
| 73 | return(rv); |
| 74 | } |
| 75 | |
| 76 | int ioloop(void) |
| 77 | { |
| 78 | int ret; |
| 79 | fd_set rfds, wfds, efds; |
| 80 | struct blocker *bl, *nbl; |
| 81 | struct timeval toval; |
| 82 | time_t now, timeout; |
| 83 | int maxfd; |
| 84 | int ev; |
| 85 | |
| 86 | exitstatus = 0; |
| 87 | while(blockers != NULL) { |
| 88 | FD_ZERO(&rfds); |
| 89 | FD_ZERO(&wfds); |
| 90 | FD_ZERO(&efds); |
| 91 | maxfd = 0; |
| 92 | now = time(NULL); |
| 93 | timeout = 0; |
| 94 | for(bl = blockers; bl; bl = bl->n) { |
| 95 | if(bl->ev & EV_READ) |
| 96 | FD_SET(bl->fd, &rfds); |
| 97 | if(bl->ev & EV_WRITE) |
| 98 | FD_SET(bl->fd, &wfds); |
| 99 | FD_SET(bl->fd, &efds); |
| 100 | if(bl->fd > maxfd) |
| 101 | maxfd = bl->fd; |
| 102 | if((bl->to != 0) && ((timeout == 0) || (timeout > bl->to))) |
| 103 | timeout = bl->to; |
| 104 | } |
| 105 | if(exitstatus) |
| 106 | return(exitstatus); |
| 107 | toval.tv_sec = timeout - now; |
| 108 | toval.tv_usec = 0; |
| 109 | ret = select(maxfd + 1, &rfds, &wfds, &efds, timeout?(&toval):NULL); |
| 110 | if(ret < 0) { |
| 111 | if(errno != EINTR) { |
| 112 | flog(LOG_CRIT, "ioloop: select errored out: %s", strerror(errno)); |
| 113 | /* To avoid CPU hogging in case it's bad, which it |
| 114 | * probably is. */ |
| 115 | sleep(1); |
| 116 | } |
| 117 | } else { |
| 118 | now = time(NULL); |
| 119 | for(bl = blockers; bl; bl = nbl) { |
| 120 | nbl = bl->n; |
| 121 | ev = 0; |
| 122 | if(FD_ISSET(bl->fd, &rfds)) |
| 123 | ev |= EV_READ; |
| 124 | if(FD_ISSET(bl->fd, &wfds)) |
| 125 | ev |= EV_WRITE; |
| 126 | if(FD_ISSET(bl->fd, &efds)) |
| 127 | ev = -1; |
| 128 | if((ev < 0) || (ev & bl->ev)) |
| 129 | resume(bl->th, ev); |
| 130 | else if((bl->to != 0) && (bl->to <= now)) |
| 131 | resume(bl->th, 0); |
| 132 | } |
| 133 | } |
| 134 | } |
| 135 | return(0); |
| 136 | } |
| 137 | |
| 138 | void exitioloop(int status) |
| 139 | { |
| 140 | exitstatus = status; |
| 141 | } |