aio_group_completion_np(3) Library Functions Manual aio_group_completion_np(3)NAME
aio_group_completion_np - Enables the use of aio_results_np function
LIBRARY
Asynchronous I/O Library (libaio, libaio_raw)
SYNOPSIS
#include <aio.h>
int aio_group_completion_np ( void );
PARAMETERS
None.
DESCRIPTION
The aio_group_completion_np function enables an application to use aio group completion through the aio_result_np function.
The function must be called before any other aio function. After this call, the use of the aio_error and aio_return functions becomes
undefined, and they may return unexpected errors. The best practice is never to intermix the two forms of aio completion. Calling the
function after the use of any other aio function results in failure.
RETURN VALUES
If the function returns successfully, the number of completed aio operations reported on is returned. That is, the return value is the
number of valid entries in the array. If the value returned is the same as the nent argument, more aio operations may be complete and can
be reported on by another call to aio_results_np.
On an unsuccessful call, a value of -1 is returned and errno is set to indicate that an error occurred.
ERRORS
The aio_group_completion_np function fails under the following conditions:
[EINVAL] Another aio function has already been called.
[EAGAIN] Inadequate system resources exist to enable group completion at this time.
RELATED INFORMATION
Functions: aio_read(3), aio_results_np(3), aio_suspend(3), aio_write(3), lio_listio(3)
Guide to Realtime Programming delim off
aio_group_completion_np(3)
Check Out this Related Man Page
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)