rt/aio_misc.h

   1 /* Copyright (C) 1997, 1999 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #ifndef _AIO_MISC_H
  20 #define _AIO_MISC_H     1
  21
  22 #include <aio.h>
  23 #include <pthread.h>
  24
  25
  26 /* Extend the operation enum.  */
  27 enum
  28 {
  29   LIO_DSYNC = LIO_READ + 1,
  30   LIO_SYNC,
  31   LIO_READ64 = LIO_READ | 128,
  32   LIO_WRITE64 = LIO_WRITE | 128
  33 };
  34
  35
  36 /* Union of the two request types.  */
  37 typedef union
  38   {
  39     struct aiocb aiocb;
  40     struct aiocb64 aiocb64;
  41   } aiocb_union;
  42
  43
  44 /* Used to synchronize.  */
  45 struct waitlist
  46   {
  47     struct waitlist *next;
  48
  49     pthread_cond_t *cond;
  50     volatile int *counterp;
  51     /* The next field is used in asynchronous `lio_listio' operations.  */
  52     struct sigevent *sigevp;
  53     /* XXX See requestlist, it's used to work around the broken signal
  54        handling in Linux.  */
  55     pid_t caller_pid;
  56   };
  57
  58
  59 /* Status of a request.  */
  60 enum
  61 {
  62   no,
  63   queued,
  64   yes,
  65   allocated
  66 };
  67
  68
  69 /* Used to queue requests..  */
  70 struct requestlist
  71   {
  72     int running;
  73
  74     struct requestlist *last_fd;
  75     struct requestlist *next_fd;
  76     struct requestlist *next_prio;
  77     struct requestlist *next_run;
  78
  79     /* Pointer to the actual data.  */
  80     aiocb_union *aiocbp;
  81
  82     /* PID of the initiator thread.
  83        XXX This is only necessary for the broken signal handling on Linux.  */
  84     pid_t caller_pid;
  85
  86     /* List of waiting processes.  */
  87     struct waitlist *waiting;
  88   };
  89
  90
  91 /* Lock for global I/O list of requests.  */
  92 extern pthread_mutex_t __aio_requests_mutex;
  93
  94
  95 /* Enqueue request.  */
  96 extern struct requestlist *__aio_enqueue_request (aiocb_union *aiocbp,
  97                                                   int operation)
  98      internal_function;
  99
 100 /* Find request entry for given AIO control block.  */
 101 extern struct requestlist *__aio_find_req (aiocb_union *elem)
 102      internal_function;
 103
 104 /* Find request entry for given file descriptor.  */
 105 extern struct requestlist *__aio_find_req_fd (int fildes) internal_function;
 106
 107 /* Release the entry for the request.  */
 108 extern void __aio_free_request (struct requestlist *req) internal_function;
 109
 110 /* Notify initiator of request and tell this everybody listening.  */
 111 extern void __aio_notify (struct requestlist *req) internal_function;
 112
 113 /* Notify initiator of request.  */
 114 extern int __aio_notify_only (struct sigevent *sigev, pid_t caller_pid)
 115      internal_function;
 116
 117 /* Send the signal.  */
 118 extern int __aio_sigqueue (int sig, const union sigval val, pid_t caller_pid)
 119      internal_function;
 120
 121 #endif /* aio_misc.h */