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1/* Copyright (C) 1996-2025 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18/*
19 * ISO/IEC 9945-1:1996 6.7: Asynchronous Input and Output
20 */
21
22#ifndef _AIO_H
23#define _AIO_H 1
24
25#include <features.h>
26#include <sys/types.h>
27#include <bits/types/sigevent_t.h>
28#include <bits/sigevent-consts.h>
29#include <bits/types/struct_timespec.h>
30
31__BEGIN_DECLS
32
33/* Asynchronous I/O control block. */
34struct aiocb
35{
36 int aio_fildes; /* File descriptor. */
37 int aio_lio_opcode; /* Operation to be performed. */
38 int aio_reqprio; /* Request priority offset. */
39 volatile void *aio_buf; /* Location of buffer. */
40 size_t aio_nbytes; /* Length of transfer. */
41 struct sigevent aio_sigevent; /* Signal number and value. */
42
43 /* Internal members. */
44 struct aiocb *__next_prio;
45 int __abs_prio;
46 int __policy;
47 int __error_code;
48 __ssize_t __return_value;
49
50#ifndef __USE_FILE_OFFSET64
51 __off_t aio_offset; /* File offset. */
52 char __pad[sizeof (__off64_t) - sizeof (__off_t)];
53#else
54 __off64_t aio_offset; /* File offset. */
55#endif
56 char __glibc_reserved[32];
57};
58
59/* The same for the 64bit offsets. Please note that the members aio_fildes
60 to __return_value have to be the same in aiocb and aiocb64. */
61#ifdef __USE_LARGEFILE64
62struct aiocb64
63{
64 int aio_fildes; /* File descriptor. */
65 int aio_lio_opcode; /* Operation to be performed. */
66 int aio_reqprio; /* Request priority offset. */
67 volatile void *aio_buf; /* Location of buffer. */
68 size_t aio_nbytes; /* Length of transfer. */
69 struct sigevent aio_sigevent; /* Signal number and value. */
70
71 /* Internal members. */
72 struct aiocb *__next_prio;
73 int __abs_prio;
74 int __policy;
75 int __error_code;
76 __ssize_t __return_value;
77
78 __off64_t aio_offset; /* File offset. */
79 char __glibc_reserved[32];
80};
81#endif
82
83
84#ifdef __USE_GNU
85/* To optimize the implementation one can use the following struct. */
86struct aioinit
87 {
88 int aio_threads; /* Maximum number of threads. */
89 int aio_num; /* Number of expected simultaneous requests. */
90 int aio_locks; /* Not used. */
91 int aio_usedba; /* Not used. */
92 int aio_debug; /* Not used. */
93 int aio_numusers; /* Not used. */
94 int aio_idle_time; /* Number of seconds before idle thread
95 terminates. */
96 int aio_reserved;
97 };
98#endif
99
100
101/* Return values of the aio_cancel function. */
102enum
103{
104 AIO_CANCELED,
105#define AIO_CANCELED AIO_CANCELED
106 AIO_NOTCANCELED,
107#define AIO_NOTCANCELED AIO_NOTCANCELED
108 AIO_ALLDONE
109#define AIO_ALLDONE AIO_ALLDONE
110};
111
112
113/* Operation codes for `aio_lio_opcode'. */
114enum
115{
116 LIO_READ,
117#define LIO_READ LIO_READ
118 LIO_WRITE,
119#define LIO_WRITE LIO_WRITE
120 LIO_NOP
121#define LIO_NOP LIO_NOP
122};
123
124
125/* Synchronization options for `lio_listio' function. */
126enum
127{
128 LIO_WAIT,
129#define LIO_WAIT LIO_WAIT
130 LIO_NOWAIT
131#define LIO_NOWAIT LIO_NOWAIT
132};
133
134
135/* Allow user to specify optimization. */
136#ifdef __USE_GNU
137extern void aio_init (const struct aioinit *__init) __THROW __nonnull ((1));
138#endif
139
140
141#ifndef __USE_FILE_OFFSET64
142/* Enqueue read request for given number of bytes and the given priority. */
143extern int aio_read (struct aiocb *__aiocbp) __THROW __nonnull ((1));
144/* Enqueue write request for given number of bytes and the given priority. */
145extern int aio_write (struct aiocb *__aiocbp) __THROW __nonnull ((1));
146
147/* Initiate list of I/O requests. */
148extern int lio_listio (int __mode,
149 struct aiocb *const __list[__restrict_arr],
150 int __nent, struct sigevent *__restrict __sig)
151 __THROW __nonnull ((2));
152
153/* Retrieve error status associated with AIOCBP. */
154extern int aio_error (const struct aiocb *__aiocbp) __THROW __nonnull ((1));
155/* Return status associated with AIOCBP. */
156extern __ssize_t aio_return (struct aiocb *__aiocbp) __THROW __nonnull ((1));
157
158/* Try to cancel asynchronous I/O requests outstanding against file
159 descriptor FILDES. */
160extern int aio_cancel (int __fildes, struct aiocb *__aiocbp) __THROW;
161
162/* Suspend calling thread until at least one of the asynchronous I/O
163 operations referenced by LIST has completed.
164
165 This function is a cancellation point and therefore not marked with
166 __THROW. */
167extern int aio_suspend (const struct aiocb *const __list[], int __nent,
168 const struct timespec *__restrict __timeout)
169 __nonnull ((1));
170
171/* Force all operations associated with file descriptor described by
172 `aio_fildes' member of AIOCBP. */
173extern int aio_fsync (int __operation, struct aiocb *__aiocbp)
174 __THROW __nonnull ((2));
175#else
176# ifdef __REDIRECT_NTH
177extern int __REDIRECT_NTH (aio_read, (struct aiocb *__aiocbp), aio_read64)
178 __nonnull ((1));
179extern int __REDIRECT_NTH (aio_write, (struct aiocb *__aiocbp), aio_write64)
180 __nonnull ((1));
181
182extern int __REDIRECT_NTH (lio_listio,
183 (int __mode,
184 struct aiocb *const __list[__restrict_arr],
185 int __nent, struct sigevent *__restrict __sig),
186 lio_listio64) __nonnull ((2));
187
188extern int __REDIRECT_NTH (aio_error, (const struct aiocb *__aiocbp),
189 aio_error64) __nonnull ((1));
190extern __ssize_t __REDIRECT_NTH (aio_return, (struct aiocb *__aiocbp),
191 aio_return64) __nonnull ((1));
192
193extern int __REDIRECT_NTH (aio_cancel,
194 (int __fildes, struct aiocb *__aiocbp),
195 aio_cancel64);
196# ifdef __USE_TIME64_REDIRECTS
197extern int __REDIRECT_NTH (aio_suspend,
198 (const struct aiocb *const __list[], int __nent,
199 const struct timespec *__restrict __timeout),
200 __aio_suspend_time64) __nonnull ((1));
201# else
202extern int __REDIRECT_NTH (aio_suspend,
203 (const struct aiocb *const __list[], int __nent,
204 const struct timespec *__restrict __timeout),
205 aio_suspend64) __nonnull ((1));
206# endif
207extern int __REDIRECT_NTH (aio_fsync,
208 (int __operation, struct aiocb *__aiocbp),
209 aio_fsync64) __nonnull ((2));
210
211# else
212# define aio_read aio_read64
213# define aio_write aio_write64
214# define lio_listio lio_listio64
215# define aio_error aio_error64
216# define aio_return aio_return64
217# define aio_cancel aio_cancel64
218# ifdef __USE_TIME64_REDIRECTS
219# define aio_suspend __aio_suspend_time64
220# else
221# define aio_suspend aio_suspend64
222# endif
223# define aio_fsync aio_fsync64
224# endif
225#endif
226
227#ifdef __USE_LARGEFILE64
228extern int aio_read64 (struct aiocb64 *__aiocbp) __THROW __nonnull ((1));
229extern int aio_write64 (struct aiocb64 *__aiocbp) __THROW __nonnull ((1));
230
231extern int lio_listio64 (int __mode,
232 struct aiocb64 *const __list[__restrict_arr],
233 int __nent, struct sigevent *__restrict __sig)
234 __THROW __nonnull ((2));
235
236extern int aio_error64 (const struct aiocb64 *__aiocbp)
237 __THROW __nonnull ((1));
238extern __ssize_t aio_return64 (struct aiocb64 *__aiocbp)
239 __THROW __nonnull ((1));
240
241extern int aio_cancel64 (int __fildes, struct aiocb64 *__aiocbp) __THROW;
242
243extern int aio_suspend64 (const struct aiocb64 *const __list[], int __nent,
244 const struct timespec *__restrict __timeout)
245 __THROW __nonnull ((1));
246
247extern int aio_fsync64 (int __operation, struct aiocb64 *__aiocbp)
248 __THROW __nonnull ((2));
249#endif
250
251__END_DECLS
252
253#endif /* aio.h */