1 /* Cancel requests associated with given file descriptor.
2 Copyright (C) 1997, 1998, 2000, 2002, 2005 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 Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the 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 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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. */
28 #define aio_cancel64 XXX
30 /* And undo the hack. */
41 aio_cancel (fildes, aiocbp)
45 struct requestlist *req = NULL;
46 int result = AIO_ALLDONE;
48 /* If fildes is invalid, error. */
49 if (fcntl (fildes, F_GETFL) < 0)
55 /* Request the mutex. */
56 pthread_mutex_lock (&__aio_requests_mutex);
58 /* We are asked to cancel a specific AIO request. */
61 /* If the AIO request is not for this descriptor it has no value
62 to look for the request block. */
63 if (aiocbp->aio_fildes != fildes)
65 pthread_mutex_unlock (&__aio_requests_mutex);
69 else if (aiocbp->__error_code == EINPROGRESS)
71 struct requestlist *last = NULL;
73 req = __aio_find_req_fd (fildes);
78 pthread_mutex_unlock (&__aio_requests_mutex);
83 while (req->aiocbp != (aiocb_union *) aiocbp)
91 /* Don't remove the entry if a thread is already working on it. */
92 if (req->running == allocated)
94 result = AIO_NOTCANCELED;
99 /* We can remove the entry. */
100 __aio_remove_request (last, req, 0);
102 result = AIO_CANCELED;
104 req->next_prio = NULL;
110 /* Find the beginning of the list of all requests for this
112 req = __aio_find_req_fd (fildes);
114 /* If any request is worked on by a thread it must be the first.
115 So either we can delete all requests or all but the first. */
118 if (req->running == allocated)
120 struct requestlist *old = req;
121 req = req->next_prio;
122 old->next_prio = NULL;
124 result = AIO_NOTCANCELED;
127 __aio_remove_request (old, req, 1);
131 result = AIO_CANCELED;
133 /* We can remove the entry. */
134 __aio_remove_request (NULL, req, 1);
139 /* Mark requests as canceled and send signal. */
142 struct requestlist *old = req;
143 assert (req->running == yes || req->running == queued);
144 req->aiocbp->aiocb.__error_code = ECANCELED;
145 req->aiocbp->aiocb.__return_value = -1;
147 req = req->next_prio;
148 __aio_free_request (old);
151 /* Release the mutex. */
152 pthread_mutex_unlock (&__aio_requests_mutex);
158 weak_alias (aio_cancel, aio_cancel64)