opera

aio_return(3)						     Library Functions Manual						     aio_return(3)

NAME

       aio_return - Returns the status of an asynchronous I/O operation (P1003.1b)

LIBRARY

       Asynchronous I/O Library (libaio, libaio_raw)

SYNOPSIS

       #include <aio.h>

       ssize_t aio_return (struct
       aiocb *aiocbp);

PARAMETERS

       *aiocbp	   A pointer to the address of the aiocb structure.

DESCRIPTION

       The  aio_return function returns the number of bytes read or written by the corresponding asynchronous I/O function.  The return status for
       an asynchronous I/O operation is the value that would be returned by the corresponding synchronous read, write, or fsync function call. The
       aio_error function returns the error status for an asynchronous I/O operation.

       The  aio_error function returns the error status associated with the specified aiocbp.  If the aio_error function returns anything but EIN-
       PROGRESS, the asynchronous I/O operation is complete. When the operation is complete, a call to the aio_return function shows if the opera-
       tion is successful.

       When  you  call	the  aio_return function, the aiocb structure is marked for reuse, thus destroying your ability to reuse the structure for
       that particular asynchronous I/O request. To avoid losing data, use the aio_error function to poll  for	completion  before  you  call  the
       aio_return  function.  Then  use the aio_return function to retrieve the number of bytes read or written during the asynchronous I/O opera-
       tion.

       If you do not call the aio_return function, the structure is not marked for reuse. In this situation, the number of asynchronous I/O opera-
       tions  available  for  use  in  your application is reduced by one for every completed asynchronous I/O operation that does not return data
       through a call to the aio_return function.

RETURN VALUES

       If the asynchronous I/O operation has completed, then the return value is any of the return values normally associated with  a  synchronous
       read,  write,  or  fsync  function  (the  number of bytes transferred or -1).  If the asynchronous I/O operation has not yet completed, the
       results of aio_return are undefined.  On an unsuccessful call, the value of -1 is returned and errno is set to indicate the error.

ERRORS

       The aio_return function fails under the following conditions:

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

RELATED INFORMATION

       Functions: close(2), exec(2), _exit(2), fork(2), lseek(2),  read(2),  write(2),	aio_cancel(3),	aio_error(3),  aio_group_completion_np(3),
       aio_read(3), aio_results_np(3), aio_suspend(3), aio_write(3), lio_listio(3)

       Guide to Realtime Programming delim off

																     aio_return(3)