src/DiskIO/DiskThreads/async_io.cc

   1
   2 /*
   3  * $Id$
   4  *
   5  * DEBUG: section 32    Asynchronous Disk I/O
   6  * AUTHOR: Pete Bentley <pete@demon.net>
   7  * AUTHOR: Stewart Forster <slf@connect.com.au>
   8  *
   9  * SQUID Web Proxy Cache          http://www.squid-cache.org/
  10  * ----------------------------------------------------------
  11  *
  12  *  Squid is the result of efforts by numerous individuals from
  13  *  the Internet community; see the CONTRIBUTORS file for full
  14  *  details.   Many organizations have provided support for Squid's
  15  *  development; see the SPONSORS file for full details.  Squid is
  16  *  Copyrighted (C) 2001 by the Regents of the University of
  17  *  California; see the COPYRIGHT file for full details.  Squid
  18  *  incorporates software developed and/or copyrighted by other
  19  *  sources; see the CREDITS file for full details.
  20  *
  21  *  This program is free software; you can redistribute it and/or modify
  22  *  it under the terms of the GNU General Public License as published by
  23  *  the Free Software Foundation; either version 2 of the License, or
  24  *  (at your option) any later version.
  25  *
  26  *  This program is distributed in the hope that it will be useful,
  27  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  29  *  GNU General Public License for more details.
  30  *
  31  *  You should have received a copy of the GNU General Public License
  32  *  along with this program; if not, write to the Free Software
  33  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  34  *
  35  */
  36
  37 #include "squid.h"
  38 #include "DiskThreads.h"
  39 #include "Store.h"
  40 #include "fde.h"
  41 #include "DiskThreadsIOStrategy.h"
  42 #include "Generic.h"
  43
  44 AIOCounts squidaio_counts;
  45
  46 typedef struct squidaio_unlinkq_t {
  47     char *path;
  48
  49     struct squidaio_unlinkq_t *next;
  50 } squidaio_unlinkq_t;
  51
  52 dlink_list used_list;
  53
  54 void
  55 aioOpen(const char *path, int oflag, mode_t mode, AIOCB * callback, void *callback_data)
  56 {
  57     squidaio_ctrl_t *ctrlp;
  58
  59     assert(DiskThreadsIOStrategy::Instance.initialised);
  60     squidaio_counts.open_start++;
  61     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
  62     ctrlp->fd = -2;
  63     ctrlp->done_handler = callback;
  64     ctrlp->done_handler_data = cbdataReference(callback_data);
  65     ctrlp->operation = _AIO_OPEN;
  66     ctrlp->result.data = ctrlp;
  67     squidaio_open(path, oflag, mode, &ctrlp->result);
  68     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
  69     return;
  70 }
  71
  72 void
  73 aioClose(int fd)
  74 {
  75     squidaio_ctrl_t *ctrlp;
  76
  77     assert(DiskThreadsIOStrategy::Instance.initialised);
  78     squidaio_counts.close_start++;
  79     aioCancel(fd);
  80     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
  81     ctrlp->fd = fd;
  82     ctrlp->done_handler = NULL;
  83     ctrlp->done_handler_data = NULL;
  84     ctrlp->operation = _AIO_CLOSE;
  85     ctrlp->result.data = ctrlp;
  86     squidaio_close(fd, &ctrlp->result);
  87     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
  88     return;
  89 }
  90
  91 void
  92 aioCancel(int fd)
  93 {
  94     squidaio_ctrl_t *ctrlp;
  95     dlink_node *m, *next;
  96
  97     assert(DiskThreadsIOStrategy::Instance.initialised);
  98     squidaio_counts.cancel++;
  99
 100     for (m = used_list.head; m; m = next) {
 101         next = m->next;
 102         ctrlp = (squidaio_ctrl_t *)m->data;
 103
 104         if (ctrlp->fd != fd)
 105             continue;
 106
 107         squidaio_cancel(&ctrlp->result);
 108
 109         if (ctrlp->done_handler) {
 110             AIOCB *callback = ctrlp->done_handler;
 111             void *cbdata;
 112             ctrlp->done_handler = NULL;
 113             debugs(32, 1, "this be aioCancel. Danger ahead!");
 114
 115             if (cbdataReferenceValidDone(ctrlp->done_handler_data, &cbdata))
 116                 callback(fd, cbdata, NULL, -2, -2);
 117
 118             /* free data if requested to aioWrite() */
 119             if (ctrlp->free_func)
 120                 ctrlp->free_func(ctrlp->bufp);
 121
 122             /* free temporary read buffer */
 123             if (ctrlp->operation == _AIO_READ)
 124                 squidaio_xfree(ctrlp->bufp, ctrlp->len);
 125         }
 126
 127         dlinkDelete(m, &used_list);
 128         DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->free(ctrlp);
 129     }
 130 }
 131
 132
 133 void
 134 aioWrite(int fd, off_t offset, char *bufp, size_t len, AIOCB * callback, void *callback_data, FREE * free_func)
 135 {
 136     squidaio_ctrl_t *ctrlp;
 137     int seekmode;
 138
 139     assert(DiskThreadsIOStrategy::Instance.initialised);
 140     squidaio_counts.write_start++;
 141     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 142     ctrlp->fd = fd;
 143     ctrlp->done_handler = callback;
 144     ctrlp->done_handler_data = cbdataReference(callback_data);
 145     ctrlp->operation = _AIO_WRITE;
 146     ctrlp->bufp = bufp;
 147     ctrlp->free_func = free_func;
 148
 149     if (offset >= 0)
 150         seekmode = SEEK_SET;
 151     else {
 152         seekmode = SEEK_END;
 153         offset = 0;
 154     }
 155
 156     ctrlp->result.data = ctrlp;
 157     squidaio_write(fd, bufp, len, offset, seekmode, &ctrlp->result);
 158     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 159 }                               /* aioWrite */
 160
 161
 162 void
 163 aioRead(int fd, off_t offset, size_t len, AIOCB * callback, void *callback_data)
 164 {
 165     squidaio_ctrl_t *ctrlp;
 166     int seekmode;
 167
 168     assert(DiskThreadsIOStrategy::Instance.initialised);
 169     squidaio_counts.read_start++;
 170     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 171     ctrlp->fd = fd;
 172     ctrlp->done_handler = callback;
 173     ctrlp->done_handler_data = cbdataReference(callback_data);
 174     ctrlp->operation = _AIO_READ;
 175     ctrlp->len = len;
 176     ctrlp->bufp = (char *)squidaio_xmalloc(len);
 177
 178     if (offset >= 0)
 179         seekmode = SEEK_SET;
 180     else {
 181         seekmode = SEEK_CUR;
 182         offset = 0;
 183     }
 184
 185     ctrlp->result.data = ctrlp;
 186     squidaio_read(fd, ctrlp->bufp, len, offset, seekmode, &ctrlp->result);
 187     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 188     return;
 189 }                               /* aioRead */
 190
 191 void
 192
 193 aioStat(char *path, struct stat *sb, AIOCB * callback, void *callback_data)
 194 {
 195     squidaio_ctrl_t *ctrlp;
 196
 197     assert(DiskThreadsIOStrategy::Instance.initialised);
 198     squidaio_counts.stat_start++;
 199     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 200     ctrlp->fd = -2;
 201     ctrlp->done_handler = callback;
 202     ctrlp->done_handler_data = cbdataReference(callback_data);
 203     ctrlp->operation = _AIO_STAT;
 204     ctrlp->result.data = ctrlp;
 205     squidaio_stat(path, sb, &ctrlp->result);
 206     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 207     return;
 208 }                               /* aioStat */
 209
 210 void
 211 aioUnlink(const char *path, AIOCB * callback, void *callback_data)
 212 {
 213     squidaio_ctrl_t *ctrlp;
 214     assert(DiskThreadsIOStrategy::Instance.initialised);
 215     squidaio_counts.unlink_start++;
 216     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 217     ctrlp->fd = -2;
 218     ctrlp->done_handler = callback;
 219     ctrlp->done_handler_data = cbdataReference(callback_data);
 220     ctrlp->operation = _AIO_UNLINK;
 221     ctrlp->result.data = ctrlp;
 222     squidaio_unlink(path, &ctrlp->result);
 223     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 224 }                               /* aioUnlink */
 225
 226 int
 227 aioQueueSize(void)
 228 {
 229     return DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->inUseCount();
 230 }