1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
/* Cancel requests associated with given file descriptor.
Copyright (C) 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* We use an UGLY hack to prevent gcc from finding us cheating. The
implementation of aio_cancel and aio_cancel64 are identical and so
we want to avoid code duplication by using aliases. But gcc sees
the different parameter lists and prints a warning. We define here
a function so that aio_cancel64 has no prototype. */
#define aio_cancel64 XXX
#include <aio.h>
/* And undo the hack. */
#undef aio_cancel64
#include <errno.h>
#include <pthread.h>
#include "aio_misc.h"
/* Argh, so far there is no ECANCELED. */
#define ECANCELED 125
int
aio_cancel (fildes, aiocbp)
int fildes;
struct aiocb *aiocbp;
{
struct aiocb *firstp;
int result = AIO_ALLDONE;
/* Request the semaphore. */
sem_wait (&__aio_requests_sema);
/* Search for the list of requests associated with the given file
descriptor. */
for (firstp = (struct aiocb *) __aio_requests; firstp != NULL;
firstp = firstp->__next_fd)
if (firstp->aio_fildes == fildes)
break;
/* If the file descriptor is not found all work seems to done
already. Otherwise try to cancel the request(s). */
if (firstp != NULL)
{
if (aiocbp != NULL)
{
/* Locate the entry corresponding to the AIOCBP parameter. */
if (aiocbp == firstp)
/* The requests is currently handled, therefore don't
cancel it and signal this to the user. */
result = AIO_NOTCANCELED;
else
{
while (firstp->__next_prio != NULL
&& aiocbp != firstp->__next_prio)
firstp = firstp->__next_prio;
if (firstp->__next_prio != NULL)
{
/* The request the user wants to cancel is in the
queue. Simply remove it. */
firstp->__next_prio = aiocbp->__next_prio;
/* Mark as canceled. */
aiocbp->__error_code = ECANCELED;
aiocbp->__return_value = -1;
/* Send the signal to notify about canceled
processing of the request. */
if (aiocbp->aio_sigevent.sigev_notify == SIGEV_THREAD)
{
/* We have to start a thread. */
pthread_t tid;
pthread_attr_t attr, *pattr;
pattr = (pthread_attr_t *)
aiocbp->aio_sigevent.sigev_notify_attributes;
if (pattr == NULL)
{
pthread_attr_init (&attr);
pthread_attr_setdetachstate (&attr,
PTHREAD_CREATE_DETACHED);
pattr = &attr;
}
pthread_create (&tid, pattr,
(void *(*) (void *))
aiocbp->aio_sigevent.sigev_notify_function,
aiocbp->aio_sigevent.sigev_value.sival_ptr);
}
else if (aiocbp->aio_sigevent.sigev_notify == SIGEV_SIGNAL)
/* We have to send a signal. */
__aio_sigqueue (aiocbp->aio_sigevent.sigev_signo,
aiocbp->aio_sigevent.sigev_value);
result = AIO_CANCELED;
}
}
}
else
{
/* First dequeue all waiting requests. */
aiocbp = firstp;
while ((firstp = firstp->__next_prio) != NULL)
{
firstp->__error_code = ECANCELED;
firstp->__return_value = -1;
/* Send the signal to notify about canceled processing
of the request. */
if (firstp->aio_sigevent.sigev_notify == SIGEV_THREAD)
{
/* We have to start a thread. */
pthread_t tid;
pthread_attr_t attr, *pattr;
pattr = (pthread_attr_t *)
aiocbp->aio_sigevent.sigev_notify_attributes;
if (pattr == NULL)
{
pthread_attr_init (&attr);
pthread_attr_setdetachstate (&attr,
PTHREAD_CREATE_DETACHED);
pattr = &attr;
}
pthread_create (&tid, pattr,
(void *(*) (void *))
firstp->aio_sigevent.sigev_notify_function,
firstp->aio_sigevent.sigev_value.sival_ptr);
}
else if (firstp->aio_sigevent.sigev_notify == SIGEV_SIGNAL)
/* We have to send a signal. */
__aio_sigqueue (firstp->aio_sigevent.sigev_signo,
firstp->aio_sigevent.sigev_value);
}
/* We have to signal that not all requests could be canceled
since the first requests is currently processed. */
result = AIO_NOTCANCELED;
aiocbp->__next_prio = NULL;
}
}
/* Release the semaphore. */
sem_post (&__aio_requests_sema);
return result;
}
weak_alias (aio_cancel, aio_cancel64)
|
