src/ioset-kevent.c

   1 /* ioset kqueue()/kevent() backend for srvx
   2  * Copyright 2008 srvx Development Team
   3  *
   4  * This file is part of srvx.
   5  *
   6  * srvx is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with srvx; if not, write to the Free Software Foundation,
  18  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
  19  */
  20
  21 #include "ioset-impl.h"
  22 #include "common.h"
  23 #include "log.h"
  24
  25 #ifdef HAVE_SYS_EVENT_H
  26 # include <sys/event.h>
  27 #endif
  28
  29 #define MAX_EVENTS 16
  30
  31 extern int clock_skew;
  32 static int kq_fd;
  33
  34 static int
  35 ioset_kevent_init(void)
  36 {
  37     kq_fd = kqueue();
  38     return kq_fd >= 0;
  39 }
  40
  41 static void
  42 ioset_kevent_add(struct io_fd *fd)
  43 {
  44     struct kevent changes[2];
  45     int nchanges = 0;
  46     int res;
  47
  48     EV_SET(&changes[nchanges++], fd->fd, EVFILT_READ, EV_ADD, 0, 0, fd);
  49     if (fd_wants_writes(fd)) {
  50        EV_SET(&changes[nchanges++], fd->fd, EVFILT_WRITE, EV_ADD, 0, 0, fd);
  51     }
  52     res = kevent(kq_fd, changes, nchanges, NULL, 0, NULL);
  53     if (res < 0) {
  54         log_module(MAIN_LOG, LOG_ERROR, "kevent() add failed: %s", strerror(errno));
  55     }
  56 }
  57
  58 static void
  59 ioset_kevent_remove(struct io_fd *fd, int closed)
  60 {
  61     if (!closed) {
  62         struct kevent changes[2];
  63         int nchanges = 0;
  64         int res;
  65
  66         EV_SET(&changes[nchanges++], fd->fd, EVFILT_READ, EV_DELETE, 0, 0, fd);
  67         EV_SET(&changes[nchanges++], fd->fd, EVFILT_WRITE, EV_DELETE, 0, 0, fd);
  68         res = kevent(kq_fd, changes, nchanges, NULL, 0, NULL);
  69         if (res < 0) {
  70             log_module(MAIN_LOG, LOG_ERROR, "kevent() remove failed: %s", strerror(errno));
  71         }
  72     }
  73 }
  74
  75 static void
  76 ioset_kevent_update(struct io_fd *fd)
  77 {
  78     struct kevent changes[2];
  79     int nchanges = 0;
  80     int res;
  81
  82     EV_SET(&changes[nchanges++], fd->fd, EVFILT_READ, EV_ADD, 0, 0, fd);
  83     EV_SET(&changes[nchanges++], fd->fd, EVFILT_WRITE, fd_wants_writes(fd) ? EV_ADD : EV_DELETE, 0, 0, fd);
  84     res = kevent(kq_fd, changes, nchanges, NULL, 0, NULL);
  85     if (res < 0) {
  86        log_module(MAIN_LOG, LOG_ERROR, "kevent() add failed: %s", strerror(errno));
  87     }
  88 }
  89
  90 static void
  91 ioset_kevent_cleanup(void)
  92 {
  93     close(kq_fd);
  94 }
  95
  96 static int
  97 ioset_kevent_loop(struct timeval *timeout)
  98 {
  99     struct kevent events[MAX_EVENTS];
 100     struct timespec ts;
 101     struct timespec *pts;
 102     int is_write;
 103     int is_read;
 104     int res;
 105     int ii;
 106
 107     /* Try to get events from the kernel. */
 108     if (timeout) {
 109         ts.tv_sec = timeout->tv_sec;
 110         ts.tv_nsec = timeout->tv_usec * 1000;
 111         pts = &ts;
 112     } else {
 113         pts = NULL;
 114     }
 115     res = kevent(kq_fd, NULL, 0, events, MAX_EVENTS, pts);
 116     if ((res < 0) && (errno != EINTR)) {
 117         log_module(MAIN_LOG, LOG_ERROR, "kevent() poll failed: %s", strerror(errno));
 118         return 1;
 119     }
 120     now = time(NULL) + clock_skew;
 121
 122     /* Process the events we got. */
 123     for (ii = 0; ii < res; ++ii) {
 124         is_write = events[ii].filter == EVFILT_WRITE;
 125         is_read = events[ii].filter == EVFILT_READ;
 126         ioset_events(events[ii].udata, is_read, is_write);
 127     }
 128
 129     return 0;
 130 }
 131
 132 struct io_engine io_engine_kevent = {
 133     .name = "kevent",
 134     .init = ioset_kevent_init,
 135     .add = ioset_kevent_add,
 136     .remove = ioset_kevent_remove,
 137     .update = ioset_kevent_update,
 138     .loop = ioset_kevent_loop,
 139     .cleanup = ioset_kevent_cleanup,
 140 };