1 /* Cancel requests associated with given file descriptor.
2 Copyright (C) 1997 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* We use an UGLY hack to prevent gcc from finding us cheating. The
23 implementation of aio_cancel and aio_cancel64 are identical and so
24 we want to avoid code duplication by using aliases. But gcc sees
25 the different parameter lists and prints a warning. We define here
26 a function so that aio_cancel64 has no prototype. */
27 #define aio_cancel64 XXX
29 /* And undo the hack. */
37 /* Argh, so far there is no ECANCELED. */
41 aio_cancel (fildes
, aiocbp
)
45 struct requestlist
*req
= NULL
;
46 int result
= AIO_ALLDONE
;
48 /* Request the mutex. */
49 pthread_mutex_lock (&__aio_requests_mutex
);
51 /* We are asked to cancel a specific AIO request. */
54 /* If the AIO request is not for this descriptor it has no value
55 to look for the request block. */
56 if (aiocbp
->aio_fildes
== fildes
)
58 struct requestlist
*last
= NULL
;
60 req
= __aio_find_req_fd (fildes
);
62 while (req
->aiocbp
!= (aiocb_union
*) aiocbp
)
68 /* Don't remove the entry if a thread is already working on it. */
69 if (req
->running
== allocated
)
70 result
= AIO_NOTCANCELED
;
73 /* We can remove the entry. */
75 last
->next_prio
= req
->next_prio
;
77 if (req
->next_prio
== NULL
)
79 if (req
->last_fd
!= NULL
)
80 req
->last_fd
->next_fd
= req
->next_fd
;
81 if (req
->next_fd
!= NULL
)
82 req
->next_fd
->last_fd
= req
->last_fd
;
86 if (req
->last_fd
!= NULL
)
87 req
->last_fd
->next_fd
= req
->next_prio
;
88 if (req
->next_fd
!= NULL
)
89 req
->next_fd
->last_fd
= req
->next_prio
;
90 req
->next_prio
->last_fd
= req
->last_fd
;
91 req
->next_prio
->next_fd
= req
->next_fd
;
93 /* Mark this entry as runnable. */
94 req
->next_prio
->running
= yes
;
97 result
= AIO_CANCELED
;
100 req
->next_prio
= NULL
;
105 /* Find the beginning of the list of all requests for this
107 req
= __aio_find_req_fd (fildes
);
109 /* If any request is worked on by a thread it must be the first.
110 So either we can delete all requests or all but the first. */
112 if (req
->running
== allocated
)
114 struct requestlist
*old
= req
;
115 req
= req
->next_prio
;
116 old
->next_prio
= NULL
;
118 result
= AIO_NOTCANCELED
;
122 /* Remove entry from the file descriptor list. */
123 if (req
->last_fd
!= NULL
)
124 req
->last_fd
->next_fd
= req
->next_fd
;
125 if (req
->next_fd
!= NULL
)
126 req
->next_fd
->last_fd
= req
->last_fd
;
128 result
= AIO_CANCELED
;
132 /* Mark requests as canceled and send signal. */
135 struct requestlist
*old
= req
;
136 req
->aiocbp
->aiocb
.__error_code
= ECANCELED
;
137 req
->aiocbp
->aiocb
.__return_value
= -1;
139 req
= req
->next_prio
;
140 __aio_free_request (old
);
143 /* Release the mutex. */
144 pthread_mutex_unlock (&__aio_requests_mutex
);
149 weak_alias (aio_cancel
, aio_cancel64
)