src/comm/ModKqueue.cc

   1 /*
   2  * $Id$
   3  *
   4  * DEBUG: section 05    Socket Functions
   5  *
   6  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   7  * ----------------------------------------------------------
   8  *
   9  *  Squid is the result of efforts by numerous individuals from
  10  *  the Internet community; see the CONTRIBUTORS file for full
  11  *  details.   Many organizations have provided support for Squid's
  12  *  development; see the SPONSORS file for full details.  Squid is
  13  *  Copyrighted (C) 2001 by the Regents of the University of
  14  *  California; see the COPYRIGHT file for full details.  Squid
  15  *  incorporates software developed and/or copyrighted by other
  16  *  sources; see the CREDITS file for full details.
  17  *
  18  *  This program is free software; you can redistribute it and/or modify
  19  *  it under the terms of the GNU General Public License as published by
  20  *  the Free Software Foundation; either version 2 of the License, or
  21  *  (at your option) any later version.
  22  *
  23  *  This program is distributed in the hope that it will be useful,
  24  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  *  GNU General Public License for more details.
  27  *
  28  *  You should have received a copy of the GNU General Public License
  29  *  along with this program; if not, write to the Free Software
  30  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  31  *
  32  */
  33
  34 /*
  35  * This code was originally written by Benno Rice and hacked on quite
  36  * a bit by Adrian. Adrian then took it to the hybrid-ircd project to use
  37  * in their new IO subsystem. After a year of modifications and some
  38  * rather interesting changes (event aggregation) its back in squid.
  39  * Thanks to the ircd-hybrid guys.
  40  */
  41
  42 /*
  43  * XXX Currently not implemented / supported by this module XXX
  44  *
  45  * - delay pools
  46  * - deferred reads
  47  * - flags.read_pending
  48  *
  49  * So, its not entirely useful in a production setup since if a read
  50  * is meant to be deferred it isn't (we're not even throwing the event
  51  * away here). Eventually the rest of the code will be rewritten
  52  * so deferred reads aren't required.
  53  *  -- adrian
  54  */
  55 #include "config.h"
  56
  57 #if USE_KQUEUE
  58
  59 #include "squid.h"
  60 #include "comm/Loops.h"
  61 #include "fde.h"
  62 #include "Store.h"
  63 #include "SquidTime.h"
  64
  65 #if HAVE_SYS_EVENT_H
  66 #include <sys/event.h>
  67 #endif
  68
  69 #define KE_LENGTH        128
  70
  71 /* jlemon goofed up and didn't add EV_SET until fbsd 4.3 */
  72
  73 #ifndef EV_SET
  74 #define EV_SET(kevp, a, b, c, d, e, f) do {     \
  75         (kevp)->ident = (a);                    \
  76         (kevp)->filter = (b);                   \
  77         (kevp)->flags = (c);                    \
  78         (kevp)->fflags = (d);                   \
  79         (kevp)->data = (e);                     \
  80         (kevp)->udata = (f);                    \
  81 } while(0)
  82 #endif
  83
  84 static void kq_update_events(int, short, PF *);
  85 static int kq;
  86
  87 static struct timespec zero_timespec;
  88
  89 static struct kevent *kqlst;        /* kevent buffer */
  90 static int kqmax;                /* max structs to buffer */
  91 static int kqoff;                /* offset into the buffer */
  92 static int max_poll_time = 1000;
  93
  94 static void commKQueueRegisterWithCacheManager(void);
  95
  96 /* XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX */
  97 /* Private functions */
  98
  99 void
 100 kq_update_events(int fd, short filter, PF * handler)
 101 {
 102     PF *cur_handler;
 103     int kep_flags;
 104
 105     switch (filter) {
 106
 107     case EVFILT_READ:
 108         cur_handler = fd_table[fd].read_handler;
 109         break;
 110
 111     case EVFILT_WRITE:
 112         cur_handler = fd_table[fd].write_handler;
 113         break;
 114
 115     default:
 116         /* XXX bad! -- adrian */
 117         return;
 118         break;
 119     }
 120
 121     if ((cur_handler == NULL && handler != NULL)
 122             || (cur_handler != NULL && handler == NULL)) {
 123
 124         struct kevent *kep;
 125
 126         kep = kqlst + kqoff;
 127
 128         if (handler != NULL) {
 129             kep_flags = (EV_ADD | EV_ONESHOT);
 130         } else {
 131             kep_flags = EV_DELETE;
 132         }
 133
 134         EV_SET(kep, (uintptr_t) fd, filter, kep_flags, 0, 0, 0);
 135
 136         /* Check if we've used the last one. If we have then submit them all */
 137         if (kqoff == kqmax - 1) {
 138             int ret;
 139
 140             ret = kevent(kq, kqlst, kqmax, NULL, 0, &zero_timespec);
 141             /* jdc -- someone needs to do error checking... */
 142
 143             if (ret == -1) {
 144                 perror("kq_update_events(): kevent()");
 145                 return;
 146             }
 147
 148             kqoff = 0;
 149         } else {
 150             kqoff++;
 151         }
 152     }
 153 }
 154
 155
 156
 157 /* XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX */
 158 /* Public functions */
 159
 160
 161 /*
 162  * comm_select_init
 163  *
 164  * This is a needed exported function which will be called to initialise
 165  * the network loop code.
 166  */
 167 void
 168 Comm::SelectLoopInit(void)
 169 {
 170     kq = kqueue();
 171
 172     if (kq < 0) {
 173         fatal("comm_select_init: Couldn't open kqueue fd!\n");
 174     }
 175
 176     kqmax = getdtablesize();
 177
 178     kqlst = (struct kevent *)xmalloc(sizeof(*kqlst) * kqmax);
 179     zero_timespec.tv_sec = 0;
 180     zero_timespec.tv_nsec = 0;
 181
 182     commKQueueRegisterWithCacheManager();
 183 }
 184
 185 /*
 186  * comm_setselect
 187  *
 188  * This is a needed exported function which will be called to register
 189  * and deregister interest in a pending IO state for a given FD.
 190  */
 191 void
 192 Comm::SetSelect(int fd, unsigned int type, PF * handler, void *client_data, time_t timeout)
 193 {
 194     fde *F = &fd_table[fd];
 195     assert(fd >= 0);
 196     assert(F->flags.open);
 197     debugs(5, 5, HERE << "FD " << fd << ", type=" << type <<
 198            ", handler=" << handler << ", client_data=" << client_data <<
 199            ", timeout=" << timeout);
 200
 201     if (type & COMM_SELECT_READ) {
 202         kq_update_events(fd, EVFILT_READ, handler);
 203         F->read_handler = handler;
 204         F->read_data = client_data;
 205     }
 206
 207     if (type & COMM_SELECT_WRITE) {
 208         kq_update_events(fd, EVFILT_WRITE, handler);
 209         F->write_handler = handler;
 210         F->write_data = client_data;
 211     }
 212
 213     if (timeout)
 214         F->timeout = squid_curtime + timeout;
 215
 216 }
 217
 218 void
 219 Comm::ResetSelect(int fd)
 220 {
 221     fde *F = &fd_table[fd];
 222     if (F->read_handler) {
 223         kq_update_events(fd, EVFILT_READ, (PF *)1);
 224     }
 225     if (F->write_handler) {
 226         kq_update_events(fd, EVFILT_WRITE, (PF *)1);
 227     }
 228 }
 229
 230 /*
 231  * Check all connections for new connections and input data that is to be
 232  * processed. Also check for connections with data queued and whether we can
 233  * write it out.
 234  */
 235
 236 /*
 237  * comm_select
 238  *
 239  * Called to do the new-style IO, courtesy of of squid (like most of this
 240  * new IO code). This routine handles the stuff we've hidden in
 241  * comm_setselect and fd_table[] and calls callbacks for IO ready
 242  * events.
 243  */
 244
 245 comm_err_t
 246 Comm::DoSelect(int msec)
 247 {
 248     int num, i;
 249
 250     static struct kevent ke[KE_LENGTH];
 251
 252     struct timespec poll_time;
 253
 254     if (msec > max_poll_time)
 255         msec = max_poll_time;
 256
 257     poll_time.tv_sec = msec / 1000;
 258
 259     poll_time.tv_nsec = (msec % 1000) * 1000000;
 260
 261     for (;;) {
 262         num = kevent(kq, kqlst, kqoff, ke, KE_LENGTH, &poll_time);
 263         ++statCounter.select_loops;
 264         kqoff = 0;
 265
 266         if (num >= 0)
 267             break;
 268
 269         if (ignoreErrno(errno))
 270             break;
 271
 272         getCurrentTime();
 273
 274         return COMM_ERROR;
 275
 276         /* NOTREACHED */
 277     }
 278
 279     getCurrentTime();
 280
 281     if (num == 0)
 282         return COMM_OK;         /* No error.. */
 283
 284     for (i = 0; i < num; i++) {
 285         int fd = (int) ke[i].ident;
 286         PF *hdl = NULL;
 287         fde *F = &fd_table[fd];
 288
 289         if (ke[i].flags & EV_ERROR) {
 290             errno = ke[i].data;
 291             /* XXX error == bad! -- adrian */
 292             continue;        /* XXX! */
 293         }
 294
 295         switch (ke[i].filter) {
 296
 297         case EVFILT_READ:
 298
 299             if ((hdl = F->read_handler) != NULL) {
 300                 F->read_handler = NULL;
 301                 F->flags.read_pending = 0;
 302                 hdl(fd, F->read_data);
 303             }
 304
 305             break;
 306
 307         case EVFILT_WRITE:
 308
 309             if ((hdl = F->write_handler) != NULL) {
 310                 F->write_handler = NULL;
 311                 hdl(fd, F->write_data);
 312             }
 313
 314             break;
 315
 316         default:
 317             /* Bad! -- adrian */
 318             debugs(5, 1, "comm_select: kevent returned " << ke[i].filter << "!");
 319             break;
 320         }
 321     }
 322
 323     return COMM_OK;
 324 }
 325
 326 void
 327 Comm::QuickPollRequired(void)
 328 {
 329     max_poll_time = 10;
 330 }
 331
 332 static void
 333 commKQueueRegisterWithCacheManager(void)
 334 {
 335 }
 336
 337 #endif /* USE_KQUEUE */