aio_return(1) retrieve return status of an asynchronous I/O operation

SYNOPSIS

#include <aio.h>

ssize_t aio_return(struct aiocb *aiocbp);

DESCRIPTION

The aio_return() function shall return the return status associated with the aiocb structure referenced by the aiocbp argument. The return status for an asynchronous I/O operation is the value that would be returned by the corresponding read(), write(), or fsync() function call. If the error status for the operation is equal to [EINPROGRESS], then the return status for the operation is undefined. The aio_return() function may be called exactly once to retrieve the return status of a given asynchronous operation; thereafter, if the same aiocb structure is used in a call to aio_return() or aio_error(), an error may be returned. When the aiocb structure referred to by aiocbp is used to submit another asynchronous operation, then aio_return() may be successfully used to retrieve the return status of that operation.

RETURN VALUE

If the asynchronous I/O operation has completed, then the return status, as described for read(), write(), and fsync(), shall be returned. If the asynchronous I/O operation has not yet completed, the results of aio_return() are undefined.

ERRORS

The aio_return() function may fail if:

EINVAL
The aiocbp argument does not refer to an asynchronous operation whose return status has not yet been retrieved.

The following sections are informative.

EXAMPLES

None.

APPLICATION USAGE

The aio_return() function is part of the Asynchronous Input and Output option and need not be available on all implementations.

RATIONALE

None.

FUTURE DIRECTIONS

None.

COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- 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 .