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, DBG_IMPORTANT, "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->freeOne(ctrlp);
 129     }
 130 }
 131
 132 void
 133 aioWrite(int fd, off_t offset, char *bufp, size_t len, AIOCB * callback, void *callback_data, FREE * free_func)
 134 {
 135     squidaio_ctrl_t *ctrlp;
 136     int seekmode;
 137
 138     assert(DiskThreadsIOStrategy::Instance.initialised);
 139     ++squidaio_counts.write_start;
 140     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 141     ctrlp->fd = fd;
 142     ctrlp->done_handler = callback;
 143     ctrlp->done_handler_data = cbdataReference(callback_data);
 144     ctrlp->operation = _AIO_WRITE;
 145     ctrlp->bufp = bufp;
 146     ctrlp->free_func = free_func;
 147
 148     if (offset >= 0)
 149         seekmode = SEEK_SET;
 150     else {
 151         seekmode = SEEK_END;
 152         offset = 0;
 153     }
 154
 155     ctrlp->result.data = ctrlp;
 156     squidaio_write(fd, bufp, len, offset, seekmode, &ctrlp->result);
 157     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 158 }                               /* aioWrite */
 159
 160 void
 161 aioRead(int fd, off_t offset, size_t len, AIOCB * callback, void *callback_data)
 162 {
 163     squidaio_ctrl_t *ctrlp;
 164     int seekmode;
 165
 166     assert(DiskThreadsIOStrategy::Instance.initialised);
 167     ++squidaio_counts.read_start;
 168     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 169     ctrlp->fd = fd;
 170     ctrlp->done_handler = callback;
 171     ctrlp->done_handler_data = cbdataReference(callback_data);
 172     ctrlp->operation = _AIO_READ;
 173     ctrlp->len = len;
 174     ctrlp->bufp = (char *)squidaio_xmalloc(len);
 175
 176     if (offset >= 0)
 177         seekmode = SEEK_SET;
 178     else {
 179         seekmode = SEEK_CUR;
 180         offset = 0;
 181     }
 182
 183     ctrlp->result.data = ctrlp;
 184     squidaio_read(fd, ctrlp->bufp, len, offset, seekmode, &ctrlp->result);
 185     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 186     return;
 187 }                               /* aioRead */
 188
 189 void
 190
 191 aioStat(char *path, struct stat *sb, AIOCB * callback, void *callback_data)
 192 {
 193     squidaio_ctrl_t *ctrlp;
 194
 195     assert(DiskThreadsIOStrategy::Instance.initialised);
 196     ++squidaio_counts.stat_start;
 197     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 198     ctrlp->fd = -2;
 199     ctrlp->done_handler = callback;
 200     ctrlp->done_handler_data = cbdataReference(callback_data);
 201     ctrlp->operation = _AIO_STAT;
 202     ctrlp->result.data = ctrlp;
 203     squidaio_stat(path, sb, &ctrlp->result);
 204     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 205     return;
 206 }                               /* aioStat */
 207
 208 void
 209 aioUnlink(const char *path, AIOCB * callback, void *callback_data)
 210 {
 211     squidaio_ctrl_t *ctrlp;
 212     assert(DiskThreadsIOStrategy::Instance.initialised);
 213     ++squidaio_counts.unlink_start;
 214     ctrlp = (squidaio_ctrl_t *)DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->alloc();
 215     ctrlp->fd = -2;
 216     ctrlp->done_handler = callback;
 217     ctrlp->done_handler_data = cbdataReference(callback_data);
 218     ctrlp->operation = _AIO_UNLINK;
 219     ctrlp->result.data = ctrlp;
 220     squidaio_unlink(path, &ctrlp->result);
 221     dlinkAdd(ctrlp, &ctrlp->node, &used_list);
 222 }                               /* aioUnlink */
 223
 224 int
 225 aioQueueSize(void)
 226 {
 227     return DiskThreadsIOStrategy::Instance.squidaio_ctrl_pool->inUseCount();
 228 }