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
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
|
/* Enqueue and list of read or write requests.
Copyright (C) 1997-2012 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, see
<http://www.gnu.org/licenses/>. */
#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
#include <shlib-compat.h>
/* We need this special structure to handle asynchronous I/O. */
struct async_waitlist
{
int counter;
struct sigevent sigev;
struct waitlist list[0];
};
/* The code in glibc 2.1 to glibc 2.4 issued only one event when all
requests submitted with lio_listio finished. The existing practice
is to issue events for the individual requests as well. This is
what the new code does. */
#if SHLIB_COMPAT (librt, GLIBC_2_1, GLIBC_2_4)
# define LIO_MODE(mode) ((mode) & 127)
# define NO_INDIVIDUAL_EVENT_P(mode) ((mode) & 128)
#else
# define LIO_MODE(mode) mode
# define NO_INDIVIDUAL_EVENT_P(mode) 0
#endif
static int
lio_listio_internal (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;
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)
{
if (NO_INDIVIDUAL_EVENT_P (mode))
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 (LIO_MODE (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 (LIO_MODE (mode) == LIO_WAIT)
{
#ifndef DONT_NEED_AIO_MISC_COND
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
int oldstate;
#endif
struct waitlist waitlist[nent];
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)
{
#ifndef DONT_NEED_AIO_MISC_COND
waitlist[cnt].cond = &cond;
#endif
waitlist[cnt].result = &result;
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;
}
}
#ifdef DONT_NEED_AIO_MISC_COND
AIO_MISC_WAIT (result, total, NULL, 0);
#else
/* Since `pthread_cond_wait'/`pthread_cond_timedwait' are cancellation
points we must be careful. We added entries to the waiting lists
which we must remove. So defer cancellation 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 cancellation state. */
pthread_setcancelstate (oldstate, NULL);
/* Release the conditional variable. */
if (pthread_cond_destroy (&cond) != 0)
/* This must never happen. */
abort ();
#endif
/* If any of the I/O requests failed, return -1 and set errno. */
if (result != 0)
{
__set_errno (result == EINTR ? EINTR : EIO);
result = -1;
}
}
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)
{
#ifndef DONT_NEED_AIO_MISC_COND
waitlist->list[cnt].cond = NULL;
#endif
waitlist->list[cnt].result = 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;
}
#if SHLIB_COMPAT (librt, GLIBC_2_1, GLIBC_2_4)
int
attribute_compat_text_section
__lio_listio_21 (int mode, struct aiocb *const list[], int nent,
struct sigevent *sig)
{
/* Check arguments. */
if (mode != LIO_WAIT && mode != LIO_NOWAIT)
{
__set_errno (EINVAL);
return -1;
}
return lio_listio_internal (mode | LIO_NO_INDIVIDUAL_EVENT, list, nent, sig);
}
compat_symbol (librt, __lio_listio_21, lio_listio, GLIBC_2_1);
#endif
int
__lio_listio_item_notify (int mode, struct aiocb *const list[], int nent,
struct sigevent *sig)
{
/* Check arguments. */
if (mode != LIO_WAIT && mode != LIO_NOWAIT)
{
__set_errno (EINVAL);
return -1;
}
return lio_listio_internal (mode, list, nent, sig);
}
versioned_symbol (librt, __lio_listio_item_notify, lio_listio, GLIBC_2_4);
|
