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
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
/* Enqueue and list of read or write requests.
Copyright (C) 1997,1998,1999,2000,2001,2003,2005
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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef lio_listio
#include <aio.h>
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <aio_misc.h>
#define LIO_OPCODE_BASE 0
#endif
/* We need this special structure to handle asynchronous I/O. */
struct async_waitlist
{
int counter;
struct sigevent sigev;
struct waitlist list[0];
};
int
lio_listio (mode, list, nent, sig)
int mode;
struct aiocb *const list[];
int nent;
struct sigevent *sig;
{
struct sigevent defsigev;
struct requestlist *requests[nent];
int cnt;
volatile int total = 0;
int result = 0;
/* Check arguments. */
if (mode != LIO_WAIT && mode != LIO_NOWAIT)
{
__set_errno (EINVAL);
return -1;
}
if (sig == NULL)
{
defsigev.sigev_notify = SIGEV_NONE;
sig = &defsigev;
}
/* Request the mutex. */
pthread_mutex_lock (&__aio_requests_mutex);
/* Now we can enqueue all requests. Since we already acquired the
mutex the enqueue function need not do this. */
for (cnt = 0; cnt < nent; ++cnt)
if (list[cnt] != NULL && list[cnt]->aio_lio_opcode != LIO_NOP)
{
list[cnt]->aio_sigevent.sigev_notify = SIGEV_NONE;
requests[cnt] = __aio_enqueue_request ((aiocb_union *) list[cnt],
(list[cnt]->aio_lio_opcode
| LIO_OPCODE_BASE));
if (requests[cnt] != NULL)
/* Successfully enqueued. */
++total;
else
/* Signal that we've seen an error. `errno' and the error code
of the aiocb will tell more. */
result = -1;
}
else
requests[cnt] = NULL;
if (total == 0)
{
/* We don't have anything to do except signalling if we work
asynchronously. */
/* Release the mutex. We do this before raising a signal since the
signal handler might do a `siglongjmp' and then the mutex is
locked forever. */
pthread_mutex_unlock (&__aio_requests_mutex);
if (mode == LIO_NOWAIT)
{
#ifdef BROKEN_THREAD_SIGNALS
__aio_notify_only (sig,
sig->sigev_notify == SIGEV_SIGNAL ? getpid () : 0);
#else
__aio_notify_only (sig);
#endif
}
return result;
}
else if (mode == LIO_WAIT)
{
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
struct waitlist waitlist[nent];
int oldstate;
total = 0;
for (cnt = 0; cnt < nent; ++cnt)
{
assert (requests[cnt] == NULL || list[cnt] != NULL);
if (requests[cnt] != NULL && list[cnt]->aio_lio_opcode != LIO_NOP)
{
waitlist[cnt].cond = &cond;
waitlist[cnt].next = requests[cnt]->waiting;
waitlist[cnt].counterp = &total;
waitlist[cnt].sigevp = NULL;
#ifdef BROKEN_THREAD_SIGNALS
waitlist[cnt].caller_pid = 0; /* Not needed. */
#endif
requests[cnt]->waiting = &waitlist[cnt];
++total;
}
}
/* Since `pthread_cond_wait'/`pthread_cond_timedwait' are cancelation
points we must be careful. We added entries to the waiting lists
which we must remove. So defer cancelation for now. */
pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate);
while (total > 0)
pthread_cond_wait (&cond, &__aio_requests_mutex);
/* Now it's time to restore the cancelation state. */
pthread_setcancelstate (oldstate, NULL);
/* Release the conditional variable. */
if (pthread_cond_destroy (&cond) != 0)
/* This must never happen. */
abort ();
}
else
{
struct async_waitlist *waitlist;
waitlist = (struct async_waitlist *)
malloc (sizeof (struct async_waitlist)
+ (nent * sizeof (struct waitlist)));
if (waitlist == NULL)
{
__set_errno (EAGAIN);
result = -1;
}
else
{
#ifdef BROKEN_THREAD_SIGNALS
pid_t caller_pid = sig->sigev_notify == SIGEV_SIGNAL ? getpid () : 0;
#endif
total = 0;
for (cnt = 0; cnt < nent; ++cnt)
{
assert (requests[cnt] == NULL || list[cnt] != NULL);
if (requests[cnt] != NULL
&& list[cnt]->aio_lio_opcode != LIO_NOP)
{
waitlist->list[cnt].cond = NULL;
waitlist->list[cnt].next = requests[cnt]->waiting;
waitlist->list[cnt].counterp = &waitlist->counter;
waitlist->list[cnt].sigevp = &waitlist->sigev;
#ifdef BROKEN_THREAD_SIGNALS
waitlist->list[cnt].caller_pid = caller_pid;
#endif
requests[cnt]->waiting = &waitlist->list[cnt];
++total;
}
}
waitlist->counter = total;
waitlist->sigev = *sig;
}
}
/* Release the mutex. */
pthread_mutex_unlock (&__aio_requests_mutex);
return result;
}
|
