Content-type: text/html Man page of aio_results_np

aio_results_np

Section: C Library Functions (3)
Index Return to Main Contents
 

NAME

aio_results_np - Return results for completed asynchronous I/O operations.  

SYNOPSIS

#include <aio.h>

typedef struct aio_completion_data {
        struct aiocb *aio_aiocb;
        ssize_t aio_result;
        int aio_error; } aio_completion_t;

int aio_results_np(
        aio_completion_t list[],
        int nent,
        const struct timespec *timeout,
        int howmany);  

PARAMETERS

An array of pointers to asynchronous I/O completion data structures. The number of elements in the array. This number specifies the number of completed asynchronous I/O operations that can be reported on. If nent is 0, the function simply returns the number of aio completions not yet reported on. A pointer to a timespec structure. If timeout is NULL, the argument is ignored. If howmany aio operations are not completed within the timeout value, the function fails. The number of aio operations that must be complete before the the call returns.  

DESCRIPTION

The aio_results_np function suspends the calling process until at least howmany asynchronous I/O operations have completed, until a signal interrupts the function, or until a timeout interval, if specified, has passed. If at the time of the call howmany asynchronous I/O operations are completed, the call returns the requested results without suspending the calling process.

The list argument is an array of pointers to aio_completion_t data structures. The nent argument indicates the number of elements in the array. On return from a successful call, the function return value specifies the number of valid entries returned in the array. For each valid entry, three pieces of information are returned: The aio_aiocb field contains a pointer to a completed aiocb structure. The aio_result field contains the return value of the operation; this value is equivalent to the result of a call to aio_return for the aio_aiocb field. The aio_error field contains the errno value of the operation; this value is equivalent to the result of a call to aio_error for the aio_aiocb field.

Each valid completion structure represents a completed aio operation. The function performs the equivalent of an aio_return on each aiocb reported that it reports on. In other words, the aiocb pointers returned are are ready for immediate reuse by the application.

If nent is 0, the function immediately returns the number of aio completions not yet reported on. This can be used to quickly poll for completion.  

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 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_results_np function fails under the following conditions: A signal interrupted the function. An invalid time value was specified in timeout. The nent parameter is negative. The list paramenter is null. The howmany parameter is greater than the nent parameter.  

RELATED INFORMATION

Functions: aio_group_completion_np(3), aio_read(3), aio_suspend(3), aio_write(3), lio_listio(3). delim off


 

Index

NAME
SYNOPSIS
PARAMETERS
DESCRIPTION
RETURN VALUES
ERRORS
RELATED INFORMATION

This document was created by man2html, using the manual pages.
Time: 02:41:58 GMT, October 02, 2010