src/DiskIO/DiskThreads/async_io.cc

   1
   2 /*
   3  * $Id: async_io.cc,v 1.3 2007/04/12 23:51:57 wessels Exp $
   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 {
  48     char *path;
  49
  50     struct squidaio_unlinkq_t *next;
  51 }
  52
  53 squidaio_unlinkq_t;
  54
  55 dlink_list used_list;
  56
  57 void
  58 aioOpen(const char *path, int oflag, mode_t mode, AIOCB * callback, void *callback_data)
  59 {
  60     squidaio_ctrl_t *ctrlp;
  61
  62     assert(DiskThreadsIOStrategy::Instance.initialised);
  63     squidaio_counts.open_start++;
  64     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
  65     ctrlp->fd = -2;
  66     ctrlp->done_handler = callback;
  67     ctrlp->done_handler_data = cbdataReference(callback_data);
  68     ctrlp->operation = _AIO_OPEN;
  69     ctrlp->result.data = ctrlp;
  70     squidaio_open(path, oflag, mode, &ctrlp->result);
  71     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
  72     return;
  73 }
  74
  75 void
  76 aioClose(int fd)
  77 {
  78     squidaio_ctrl_t *ctrlp;
  79
  80     assert(DiskThreadsIOStrategy::Instance.initialised);
  81     squidaio_counts.close_start++;
  82     aioCancel(fd);
  83     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
  84     ctrlp->fd = fd;
  85     ctrlp->done_handler = NULL;
  86     ctrlp->done_handler_data = NULL;
  87     ctrlp->operation = _AIO_CLOSE;
  88     ctrlp->result.data = ctrlp;
  89     squidaio_close(fd, &ctrlp->result);
  90     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
  91     return;
  92 }
  93
  94 void
  95 aioCancel(int fd)
  96 {
  97     squidaio_ctrl_t *ctrlp;
  98     dlink_node *m, *next;
  99
 100     assert(DiskThreadsIOStrategy::Instance.initialised);
 101     squidaio_counts.cancel++;
 102
 103     for (m = used_list.head; m; m = next) {
 104         next = m->next;
 105         ctrlp = (squidaio_ctrl_t *)m->data;
 106
 107         if (ctrlp->fd != fd)
 108             continue;
 109
 110         squidaio_cancel(&ctrlp->result);
 111
 112         if (ctrlp->done_handler) {
 113             AIOCB *callback = ctrlp->done_handler;
 114             void *cbdata;
 115             ctrlp->done_handler = NULL;
 116             debug(32, 1) ("this be aioCancel. Danger ahead!\n");
 117
 118             if (cbdataReferenceValidDone(ctrlp->done_handler_data, &cbdata))
 119                 callback(fd, cbdata, NULL, -2, -2);
 120
 121             /* free data if requested to aioWrite() */
 122             if (ctrlp->free_func)
 123                 ctrlp->free_func(ctrlp->bufp);
 124
 125             /* free temporary read buffer */
 126             if (ctrlp->operation == _AIO_READ)
 127                 squidaio_xfree(ctrlp->bufp, ctrlp->len);
 128         }
 129
 130         dlinkDelete(m, &used_list);
 131         DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->free(ctrlp);
 132     }
 133 }
 134
 135
 136 void
 137 aioWrite(int fd, int offset, char *bufp, int len, AIOCB * callback, void *callback_data, FREE * free_func)
 138 {
 139     squidaio_ctrl_t *ctrlp;
 140     int seekmode;
 141
 142     assert(DiskThreadsIOStrategy::Instance.initialised);
 143     squidaio_counts.write_start++;
 144     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 145     ctrlp->fd = fd;
 146     ctrlp->done_handler = callback;
 147     ctrlp->done_handler_data = cbdataReference(callback_data);
 148     ctrlp->operation = _AIO_WRITE;
 149     ctrlp->bufp = bufp;
 150     ctrlp->free_func = free_func;
 151
 152     if (offset >= 0)
 153         seekmode = SEEK_SET;
 154     else {
 155         seekmode = SEEK_END;
 156         offset = 0;
 157     }
 158
 159     ctrlp->result.data = ctrlp;
 160     squidaio_write(fd, bufp, len, offset, seekmode, &ctrlp->result);
 161     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 162 }                               /* aioWrite */
 163
 164
 165 void
 166 aioRead(int fd, int offset, int len, AIOCB * callback, void *callback_data)
 167 {
 168     squidaio_ctrl_t *ctrlp;
 169     int seekmode;
 170
 171     assert(DiskThreadsIOStrategy::Instance.initialised);
 172     squidaio_counts.read_start++;
 173     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 174     ctrlp->fd = fd;
 175     ctrlp->done_handler = callback;
 176     ctrlp->done_handler_data = cbdataReference(callback_data);
 177     ctrlp->operation = _AIO_READ;
 178     ctrlp->len = len;
 179     ctrlp->bufp = (char *)squidaio_xmalloc(len);
 180
 181     if (offset >= 0)
 182         seekmode = SEEK_SET;
 183     else {
 184         seekmode = SEEK_CUR;
 185         offset = 0;
 186     }
 187
 188     ctrlp->result.data = ctrlp;
 189     squidaio_read(fd, ctrlp->bufp, len, offset, seekmode, &ctrlp->result);
 190     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 191     return;
 192 }                               /* aioRead */
 193
 194 void
 195
 196 aioStat(char *path, struct stat *sb, AIOCB * callback, void *callback_data)
 197 {
 198     squidaio_ctrl_t *ctrlp;
 199
 200     assert(DiskThreadsIOStrategy::Instance.initialised);
 201     squidaio_counts.stat_start++;
 202     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 203     ctrlp->fd = -2;
 204     ctrlp->done_handler = callback;
 205     ctrlp->done_handler_data = cbdataReference(callback_data);
 206     ctrlp->operation = _AIO_STAT;
 207     ctrlp->result.data = ctrlp;
 208     squidaio_stat(path, sb, &ctrlp->result);
 209     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 210     return;
 211 }                               /* aioStat */
 212
 213 void
 214 aioUnlink(const char *path, AIOCB * callback, void *callback_data)
 215 {
 216     squidaio_ctrl_t *ctrlp;
 217     assert(DiskThreadsIOStrategy::Instance.initialised);
 218     squidaio_counts.unlink_start++;
 219     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 220     ctrlp->fd = -2;
 221     ctrlp->done_handler = callback;
 222     ctrlp->done_handler_data = cbdataReference(callback_data);
 223     ctrlp->operation = _AIO_UNLINK;
 224     ctrlp->result.data = ctrlp;
 225     squidaio_unlink(path, &ctrlp->result);
 226     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 227 }                               /* aioUnlink */
 228
 229 int
 230 aioQueueSize(void)
 231 {
 232     return DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->inUseCount();
 233 }