NAME

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

SYNOPSIS

[AIO] #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.

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.

SEE ALSO

aio_cancel() , aio_error() , aio_fsync() , aio_read() , aio_write() , close() , exec() , exit() , fork() , lio_listio() , lseek() , read() , the Base Definitions volume of IEEE Std 1003.1-2001, <aio.h>

CHANGE HISTORY

First released in Issue 5. Included for alignment with the POSIX Realtime Extension.

Issue 6

The [ENOSYS] error condition has been removed as stubs need not be provided if an implementation does not support the Asynchronous Input and Output option.

The APPLICATION USAGE section is added.

The [EINVAL] error condition is updated as a "may fail". This is for consistency with the DESCRIPTION.