AIOWAIT(3C) Standard C Library Functions AIOWAIT(3C)

NAME

aiowait - wait for completion of asynchronous I/O operation

SYNOPSIS

#include <sys/asynch.h>
#include <sys/time.h>

aio_result_t *aiowait(const struct timeval *timeout);

DESCRIPTION

The aiowait() function suspends the calling process until one of its
outstanding asynchronous I/O operations completes, providing a
synchronous method of notification.


If timeout is a non-zero pointer, it specifies a maximum interval to wait
for the completion of an asynchronous I/O operation. If timeout is a zero
pointer, aiowait() blocks indefinitely. To effect a poll, the timeout
parameter should be non-zero, pointing to a zero-valued timeval
structure.


The timeval structure is defined in <sys/time.h> and contains the
following members:

long tv_sec; /* seconds */
long tv_usec; /* and microseconds */

RETURN VALUES

Upon successful completion, aiowait() returns a pointer to the result
structure used when the completed asynchronous I/O operation was
requested. Upon failure, aiowait() returns -1 and sets errno to indicate
the error. aiowait() returns 0 if the time limit expires.

ERRORS

The aiowait() function will fail if:

EFAULT
The timeout argument points to an address outside the address
space of the requesting process. See NOTES.


EINTR
The execution of aiowait() was interrupted by a signal.


EINVAL
There are no outstanding asynchronous I/O requests.


EINVAL
The tv_secs member of the timeval structure pointed to by
timeout is less than 0 or the tv_usecs member is greater than
the number of seconds in a microsecond.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT-Level | Safe |
+---------------+-----------------+

SEE ALSO

aiocancel(3C), aioread(3C), attributes(7)

NOTES

The aiowait() function is the only way to dequeue an asynchronous
notification. It can be used either inside a SIGIO signal handler or in
the main program. One SIGIO signal can represent several queued events.


Passing an illegal address as timeout will result in setting errno to
EFAULT only if detected by the application process.

February 5, 2008 AIOWAIT(3C)