src/comm/ModKqueue.cc

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