1lio_listio(3C) Standard C Library Functions lio_listio(3C)
2
6 lio_listio - list directed I/O
7
9 #include <aio.h>
10 int lio_listio(int mode, struct aiocb *restrict const list[],
12 int nent, struct sigevent *restrict sig);
13
16 The lio_listio() function allows the calling process, LWP, or thread,
17 to initiate a list of I/O requests within a single function call.
18 The mode argument takes one of the values LIO_WAIT or LIO_NOWAIT
21 declared in <aio.h> and determines whether the function returns when
22 the I/O operations have been completed, or as soon as the operations
23 have been queued. If the mode argument is LIO_WAIT, the function waits
24 until all I/O is complete and the sig argument is ignored.
25 If the mode argument is LIO_NOWAIT, the function returns immediately,
28 and asynchronous notification occurs, according to the sig argument,
29 when all the I/O operations complete. If sig is NULL, no asynchronous
30 notification occurs. If sig is not NULL, asynchronous notification
31 occurs as specified in signal.h(3HEAD) when all the requests in list
32 have completed.
33 The I/O requests enumerated by list are submitted in an unspecified
36 order.
37 The list argument is an array of pointers to aiocb structures. The
40 array contains nent elements. The array may contain null elements,
41 which are ignored.
42 The aio_lio_opcode field of each aiocb structure specifies the opera‐
45 tion to be performed. The supported operations are LIO_READ, LIO_WRITE,
46 and LIO_NOP; these symbols are defined in <aio.h>. The LIO_NOP opera‐
47 tion causes the list entry to be ignored. If the aio_lio_opcode element
48 is equal to LIO_READ, then an I/O operation is submitted as if by a
49 call to aio_read(3C) with the aiocbp equal to the address of the aiocb
50 structure. If the aio_lio_opcode element is equal to LIO_WRITE, then an
51 I/O operation is submitted as if by a call to aio_write(3C) with the
52 aiocbp equal to the address of the aiocb structure.
53 The aio_fildes member specifies the file descriptor on which the opera‐
56 tion is to be performed.
57 The aio_buf member specifies the address of the buffer to or from which
60 the data is to be transferred.
61 The aio_nbytes member specifies the number of bytes of data to be
64 transferred.
65 The members of the aiocb structure further describe the I/O operation
68 to be performed, in a manner identical to that of the corresponding
69 aiocb structure when used by the aio_read(3C) and aio_write(3C) func‐
70 tions.
71 The nent argument specifies how many elements are members of the list,
74 that is, the length of the array.
75 The behavior of this function is altered according to the definitions
78 of synchronized I/O data integrity completion and synchronized I/O file
79 integrity completion if synchronized I/O is enabled on the file associ‐
80 ated with aio_fildes. See fcntl.h(3HEAD) definitions of O_DSYNC and
81 O_SYNC.
82 For regular files, no data transfer will occur past the offset maximum
85 established in the open file description associated with
86 aiocbp→aio_fildes.
87
89 If the mode argument has the value LIO_NOWAIT, and the I/O operations
90 are successfully queued, lio_listio() returns 0; otherwise, it returns
91 −1, and sets errno to indicate the error.
92 If the mode argument has the value LIO_WAIT, and all the indicated
95 I/O has completed successfully, lio_listio() returns 0; otherwise, it
96 returns −1, and sets errno to indicate the error.
97 In either case, the return value only indicates the success or failure
100 of the lio_listio() call itself, not the status of the individual I/O
101 requests. In some cases, one or more of the I/O requests contained in
102 the list may fail. Failure of an individual request does not prevent
103 completion of any other individual request. To determine the outcome
104 of each I/O request, the application must examine the error status
105 associated with each aiocb control block. Each error status so
106 returned is identical to that returned as a result of an aio_read(3C)
107 or aio_write(3C) function.
108
110 The lio_listio() function will fail if:
111 EAGAIN The resources necessary to queue all the I/O requests were
113 not available. The error status for each request is recorded
114 in the aio_error member of the corresponding aiocb structure,
115 and can be retrieved using aio_error(3C).
116 EAGAIN The number of entries indicated by nent would cause the sys‐
119 tem-wide limit AIO_MAX to be exceeded.
120 EINVAL The mode argument is an improper value, or the value of nent
123 is greater than AIO_LISTIO_MAX.
124 EINTR A signal was delivered while waiting for all I/O requests to
127 complete during an LIO_WAIT operation. Note that, since each
128 I/O operation invoked by lio_listio() may possibly provoke a
129 signal when it completes, this error return may be caused by
130 the completion of one (or more) of the very I/O operations
131 being awaited. Outstanding I/O requests are not canceled, and
132 the application can use aio_fsync(3C) to determine if any
133 request was initiated; aio_return(3C) to determine if any
134 request has completed; or aio_error(3C) to determine if any
135 request was canceled.
136 EIO One or more of the individual I/O operations failed. The
139 application can use aio_error(3C) to check the error status
140 for each aiocb structure to determine the individual
141 request(s) that failed.
142 In addition to the errors returned by the lio_listio() function, if the
146 lio_listio() function succeeds or fails with errors of EAGAIN, EINTR,
147 or EIO, then some of the I/O specified by the list may have been initi‐
148 ated. If the lio_listio() function fails with an error code other than
149 EAGAIN, EINTR, or EIO, no operations from the list have been initiated.
150 The I/O operation indicated by each list element can encounter errors
151 specific to the individual read or write function being performed. In
152 this event, the error status for each aiocb control block contains the
153 associated error code. The error codes that can be set are the same as
154 would be set by a read(2) or write(2) function, with the following
155 additional error codes possible:
156 EAGAIN The requested I/O operation was not queued due to
158 resource limitations.
159 ECANCELED The requested I/O was canceled before the I/O completed
162 due to an explicit aio_cancel(3C) request.
163 EFBIG The aiocbp→aio_lio_opcode is LIO_WRITE, the file is a
166 regular file, aiocbp→aio_nbytes is greater than 0, and
167 the aiocbp→aio_offset is greater than or equal to the
168 offset maximum in the open file description associated
169 with aiocbp→aio_fildes.
170 EINPROGRESS The requested I/O is in progress.
173 EOVERFLOW The aiocbp→aio_lio_opcode is LIO_READ, the file is a
176 regular file, aiocbp→aio_nbytes is greater than 0, and
177 the aiocbp→aio_offset is before the end-of-file and is
178 greater than or equal to the offset maximum in the open
179 file description associated with aiocbp→aio_fildes.
180
183 The lio_listio() function has a transitional interface for 64-bit file
184 offsets. See lf64(5).
185
187 See attributes(5) for descriptions of the following attributes:
188 ┌─────────────────────────────┬─────────────────────────────┐
193 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
194 ├─────────────────────────────┼─────────────────────────────┤
195 │Interface Stability │Committed │
196 ├─────────────────────────────┼─────────────────────────────┤
197 │MT-Level │MT-Safe │
198 ├─────────────────────────────┼─────────────────────────────┤
199 │Standard │See standards(5). │
200 └─────────────────────────────┴─────────────────────────────┘
201
203 close(2), exec(2), exit(2), fork(2), lseek(2), read(2), write(2),
204 aio_cancel(3C), aio_error(3C), aio_fsync(3C), aio_read(3C),
205 aio_return(3C), aio_write(3C), aio.h(3HEAD), fcntl.h(3HEAD), sig‐
206 info.h(3HEAD), signal.h(3HEAD), attributes(5), lf64(5), standards(5)
207SunOS 5.11 5 Feb 2008 lio_listio(3C)