src/DiskIO/DiskThreads/async_io.cc

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