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
|
/* Cancel requests associated with given file descriptor.
Copyright (C) 1997, 1998 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 "aio_misc.h"
int
aio_cancel (fildes, aiocbp)
int fildes;
struct aiocb *aiocbp;
{
struct requestlist *req = NULL;
int result = AIO_ALLDONE;
/* Request the mutex. */
pthread_mutex_lock (&__aio_requests_mutex);
/* We are asked to cancel a specific AIO request. */
if (aiocbp != NULL)
{
/* If the AIO request is not for this descriptor it has no value
to look for the request block. */
if (aiocbp->aio_fildes == fildes)
{
struct requestlist *last = NULL;
req = __aio_find_req_fd (fildes);
while (req->aiocbp != (aiocb_union *) aiocbp)
{
last = req;
req = req->next_prio;
}
/* Don't remove the entry if a thread is already working on it. */
if (req->running == allocated)
result = AIO_NOTCANCELED;
else
{
/* We can remove the entry. */
if (last != NULL)
last->next_prio = req->next_prio;
else
if (req->next_prio == NULL)
{
if (req->last_fd != NULL)
req->last_fd->next_fd = req->next_fd;
if (req->next_fd != NULL)
req->next_fd->last_fd = req->last_fd;
}
else
{
if (req->last_fd != NULL)
req->last_fd->next_fd = req->next_prio;
if (req->next_fd != NULL)
req->next_fd->last_fd = req->next_prio;
req->next_prio->last_fd = req->last_fd;
req->next_prio->next_fd = req->next_fd;
/* Mark this entry as runnable. */
req->next_prio->running = yes;
}
result = AIO_CANCELED;
}
req->next_prio = NULL;
}
}
else
{
/* Find the beginning of the list of all requests for this
desriptor. */
req = __aio_find_req_fd (fildes);
/* If any request is worked on by a thread it must be the first.
So either we can delete all requests or all but the first. */
if (req != NULL)
if (req->running == allocated)
{
struct requestlist *old = req;
req = req->next_prio;
old->next_prio = NULL;
result = AIO_NOTCANCELED;
}
else
{
/* Remove entry from the file descriptor list. */
if (req->last_fd != NULL)
req->last_fd->next_fd = req->next_fd;
if (req->next_fd != NULL)
req->next_fd->last_fd = req->last_fd;
result = AIO_CANCELED;
}
}
/* Mark requests as canceled and send signal. */
while (req != NULL)
{
struct requestlist *old = req;
req->aiocbp->aiocb.__error_code = ECANCELED;
req->aiocbp->aiocb.__return_value = -1;
__aio_notify (req);
req = req->next_prio;
__aio_free_request (old);
}
/* Release the mutex. */
pthread_mutex_unlock (&__aio_requests_mutex);
return result;
}
weak_alias (aio_cancel, aio_cancel64)
|
