aio.h(3head) [posix man page]

<aio.h>(P)						     POSIX Programmer's Manual							<aio.h>(P)

NAME

       aio.h - asynchronous input and output (REALTIME)

SYNOPSIS

       #include <aio.h>

DESCRIPTION

       The <aio.h> header shall define the aiocb structure which shall include at least the following members:

	      int	      aio_fildes     File descriptor.
	      off_t	      aio_offset     File offset.
	      volatile void  *aio_buf	     Location of buffer.
	      size_t	      aio_nbytes     Length of transfer.
	      int	      aio_reqprio    Request priority offset.
	      struct sigevent aio_sigevent   Signal number and value.
	      int	      aio_lio_opcode Operation to be performed.

       This header shall also include the following constants:

       AIO_ALLDONE
	      A return value indicating that none of the requested operations could be canceled since they are already complete.

       AIO_CANCELED
	      A return value indicating that all requested operations have been canceled.

       AIO_NOTCANCELED

	      A return value indicating that some of the requested operations could not be canceled since they are in progress.

       LIO_NOP
	      A lio_listio() element operation option indicating that no transfer is requested.

       LIO_NOWAIT
	      A  lio_listio()  synchronization operation indicating that the calling thread is to continue execution while the lio_listio() opera-
	      tion is being performed, and no notification is given when the operation is complete.

       LIO_READ
	      A lio_listio() element operation option requesting a read.

       LIO_WAIT
	      A lio_listio() synchronization operation indicating that the calling thread is to suspend until the lio_listio() operation  is  com-
	      plete.

       LIO_WRITE
	      A lio_listio() element operation option requesting a write.

       The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.

	      int      aio_cancel(int, struct aiocb *);
	      int      aio_error(const struct aiocb *);
	      int      aio_fsync(int, struct aiocb *);
	      int      aio_read(struct aiocb *);
	      ssize_t  aio_return(struct aiocb *);
	      int      aio_suspend(const struct aiocb *const[], int,
			   const struct timespec *);
	      int      aio_write(struct aiocb *);
	      int      lio_listio(int, struct aiocb *restrict const[restrict], int,
			   struct sigevent *restrict);

       Inclusion of the <aio.h> header may make visible symbols defined in the headers <fcntl.h>, <signal.h>, <sys/types.h>, and <time.h>.

       The following sections are informative.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       <fcntl.h> , <signal.h> , <sys/types.h> , <time.h> , the System Interfaces volume of IEEE Std 1003.1-2001, fsync(), lseek(), read(), write()

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
       Electrical  and	Electronics  Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE
       and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can  be  obtained
       online at http://www.opengroup.org/unix/online.html .

IEEE
/The Open Group						       2003								<aio.h>(P)

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LIO_LISTIO(2)						      BSD System Calls Manual						     LIO_LISTIO(2)

NAME

     lio_listio -- list directed I/O (REALTIME)

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <aio.h>

     int
     lio_listio(int mode, struct aiocb * const list[], int nent, struct sigevent *sig);

DESCRIPTION

     The lio_listio() function initiates a list of I/O requests with a single function call.  The list argument is an array of pointers to aiocb
     structures describing each operation to perform, with nent elements.  NULL elements are ignored.

     The aio_lio_opcode field of each aiocb specifies the operation to be performed.  The following operations are supported:

     LIO_READ	Read data as if by a call to aio_read(2).

     LIO_NOP	No operation.

     LIO_WRITE	Write data as if by a call to aio_write(2).

     If the mode argument is LIO_WAIT, lio_listio() does not return until all the requested operations have been completed.  If mode is
     LIO_NOWAIT, the requests are processed asynchronously, and the signal specified by sig is sent when all operations have completed.  If sig is
     NULL, the calling process is not notified of I/O completion.

     The order in which the requests are carried out is not specified; in particular, there is no guarantee that they will be executed in the
     order 0, 1, ..., nent-1.

RETURN VALUES

     If mode is LIO_WAIT, the lio_listio() function returns 0 if the operations completed successfully, otherwise -1.

     If mode is LIO_NOWAIT, the lio_listio() function returns 0 if the operations are successfully queued, otherwise -1.

ERRORS

     The lio_listio() function will fail if:

     [EAGAIN]		There are not enough resources to enqueue the requests.

     [EAGAIN]		The request would cause the system-wide limit AIO_MAX to be exceeded.

     [EINVAL]		The mode argument is neither LIO_WAIT nor LIO_NOWAIT, or nent is greater than AIO_LISTIO_MAX.

     [EINTR]		A signal interrupted the system call before it could be completed.

     [EIO]		One or more requests failed.

     In addition, the lio_listio() function may fail for any of the reasons listed for aio_read(2) and aio_write(2).

     If lio_listio() succeeds, or fails with an error code of EAGAIN, EINTR, or EIO, some of the requests may have been initiated.  The caller
     should check the error status of each aiocb structure individually by calling aio_error(2).

SEE ALSO

     aio_error(2), aio_read(2), aio_write(2), read(2), write(2), siginfo(3), aio(4)

STANDARDS

     The lio_listio() function is expected to conform to IEEE Std 1003.1-2001 (``POSIX.1'').

BSD
								 January 12, 2003							       BSD

Linux and UNIX Man Pages

aio.h(3head) [posix man page]

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