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 "globals.h"
  59 #include "SquidTime.h"
  60 #include "StatCounters.h"
  61 #include "Store.h"
  62
  63 #include <cerrno>
  64 #if HAVE_SYS_EVENT_H
  65 #include <sys/event.h>
  66 #endif
  67
  68 #define KE_LENGTH        128
  69
  70 /* jlemon goofed up and didn't add EV_SET until fbsd 4.3 */
  71
  72 #ifndef EV_SET
  73 #define EV_SET(kevp, a, b, c, d, e, f) do {     \
  74         (kevp)->ident = (a);                    \
  75         (kevp)->filter = (b);                   \
  76         (kevp)->flags = (c);                    \
  77         (kevp)->fflags = (d);                   \
  78         (kevp)->data = (e);                     \
  79         (kevp)->udata = (f);                    \
  80 } while(0)
  81 #endif
  82
  83 static void kq_update_events(int, short, PF *);
  84 static int kq;
  85
  86 static struct timespec zero_timespec;
  87
  88 static struct kevent *kqlst;        /* kevent buffer */
  89 static int kqmax;                /* max structs to buffer */
  90 static int kqoff;                /* offset into the buffer */
  91 static int max_poll_time = 1000;
  92
  93 static void commKQueueRegisterWithCacheManager(void);
  94
  95 /* XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX */
  96 /* Private functions */
  97
  98 void
  99 kq_update_events(int fd, short filter, PF * handler)
 100 {
 101     PF *cur_handler;
 102     int kep_flags;
 103
 104     switch (filter) {
 105
 106     case EVFILT_READ:
 107         cur_handler = fd_table[fd].read_handler;
 108         break;
 109
 110     case EVFILT_WRITE:
 111         cur_handler = fd_table[fd].write_handler;
 112         break;
 113
 114     default:
 115         /* XXX bad! -- adrian */
 116         return;
 117         break;
 118     }
 119
 120     if ((cur_handler == NULL && handler != NULL)
 121             || (cur_handler != NULL && handler == NULL)) {
 122
 123         struct kevent *kep;
 124
 125         kep = kqlst + kqoff;
 126
 127         if (handler != NULL) {
 128             kep_flags = (EV_ADD | EV_ONESHOT);
 129         } else {
 130             kep_flags = EV_DELETE;
 131         }
 132
 133         EV_SET(kep, (uintptr_t) fd, filter, kep_flags, 0, 0, 0);
 134
 135         /* Check if we've used the last one. If we have then submit them all */
 136         if (kqoff == kqmax - 1) {
 137             int ret;
 138
 139             ret = kevent(kq, kqlst, kqmax, NULL, 0, &zero_timespec);
 140             /* jdc -- someone needs to do error checking... */
 141
 142             if (ret == -1) {
 143                 perror("kq_update_events(): kevent()");
 144                 return;
 145             }
 146
 147             kqoff = 0;
 148         } else {
 149             ++kqoff;
 150         }
 151     }
 152 }
 153
 154 /* XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX */
 155 /* Public functions */
 156
 157 /*
 158  * comm_select_init
 159  *
 160  * This is a needed exported function which will be called to initialise
 161  * the network loop code.
 162  */
 163 void
 164 Comm::SelectLoopInit(void)
 165 {
 166     kq = kqueue();
 167
 168     if (kq < 0) {
 169         fatal("comm_select_init: Couldn't open kqueue fd!\n");
 170     }
 171
 172     kqmax = getdtablesize();
 173
 174     kqlst = (struct kevent *)xmalloc(sizeof(*kqlst) * kqmax);
 175     zero_timespec.tv_sec = 0;
 176     zero_timespec.tv_nsec = 0;
 177
 178     commKQueueRegisterWithCacheManager();
 179 }
 180
 181 /*
 182  * comm_setselect
 183  *
 184  * This is a needed exported function which will be called to register
 185  * and deregister interest in a pending IO state for a given FD.
 186  */
 187 void
 188 Comm::SetSelect(int fd, unsigned int type, PF * handler, void *client_data, time_t timeout)
 189 {
 190     fde *F = &fd_table[fd];
 191     assert(fd >= 0);
 192     assert(F->flags.open);
 193     debugs(5, 5, HERE << "FD " << fd << ", type=" << type <<
 194            ", handler=" << handler << ", client_data=" << client_data <<
 195            ", timeout=" << timeout);
 196
 197     if (type & COMM_SELECT_READ) {
 198         if (F->flags.read_pending)
 199             kq_update_events(fd, EVFILT_WRITE, handler);
 200
 201         kq_update_events(fd, EVFILT_READ, handler);
 202
 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::Flag
 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::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         if (ke[i].filter == EVFILT_READ || F->flags.read_pending) {
 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
 303         if (ke[i].filter == EVFILT_WRITE) {
 304             if ((hdl = F->write_handler) != NULL) {
 305                 F->write_handler = NULL;
 306                 hdl(fd, F->write_data);
 307             }
 308         }
 309
 310         if (ke[i].filter != EVFILT_WRITE && ke[i].filter != EVFILT_READ) {
 311             /* Bad! -- adrian */
 312             debugs(5, DBG_IMPORTANT, "comm_select: kevent returned " << ke[i].filter << "!");
 313         }
 314     }
 315
 316     return Comm::OK;
 317 }
 318
 319 void
 320 Comm::QuickPollRequired(void)
 321 {
 322     max_poll_time = 10;
 323 }
 324
 325 static void
 326 commKQueueRegisterWithCacheManager(void)
 327 {
 328 }
 329
 330 #endif /* USE_KQUEUE */