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aio_results_np(3)
NAME
  aio_results_np - Returns 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 listchoice="opt">,
  int nent,
  const struct timespec *timeout,
  int howmany);

LIBRARY
  Asynchronous I/O Library (libaio, libaio_raw)

PARAMETERS
  list
      An array of pointers to asynchronous I/O completion data structures.

  nent
      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 (zero), the function simply returns the number of aio
      completions not yet reported on.

  timeout
      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.

  howmany
      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 on which it
  reports.  In other words, the aiocb pointers returned are ready for
  immediate reuse by the application.

  If nent is 0 (zero), 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:

  [EINTR]
      A signal interrupted the function.

  [EINVAL]
      An invalid time value was specified in timeout.

  [EINVAL]
      The nent parameter is negative.

  [EINVAL]
      The list paramenter is null.

  [EINVAL]
      The howmany parameter is greater than the nent parameter.

SEE ALSO
  Functions: aio_group_completion_np(3), aio_read(3), aio_suspend(3),
  aio_write(3), lio_listio(3)

  Guide to Realtime Programming

Index for Section 3

Alphabetical listing for A

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