NAME

aio_return, aio_error − retrieve return or error status of asynchronous I/O operation

SYNOPSIS

cc [ flag ... ] file ... −lposix4 [ library ... ]

#include <aio.h>

ssize_t aio_return(struct aiocb ∗ aiocbp);

int aio_error(const struct aiocb ∗ aiocbp);

struct aiocb {
   intaio_fildes;/∗ file descriptor ∗/
   volatile void∗aio_buf;/∗ buffer location ∗/
   size_taio_nbytes;/∗ length of transfer ∗/
   off_taio_offset;/∗ file offset ∗/
   intaio_reqprio;/∗ request priority offset ∗/
   struct sigeventaio_sigevent;/∗ signal number and offset ∗/
   intaio_lio_opcode; /∗ listio operation ∗/
};

struct sigevent {
   intsigev_notify;/∗ notification mode ∗/
   intsigev_signo;/∗ signal number ∗/
   union sigvalsigev_value;/∗ signal value ∗/
};

union sigval {
   intsival_int;/∗ integer value ∗/
   void∗sival_ptr;/∗ pointer value ∗/
};

MT-LEVEL

Async-Signal-Safe

DESCRIPTION

aio_return() returns the return status of the asynchronous I/O request associated with the aiocb structure pointed to by aiocbp. 

aio_error() returns the error status of the asynchronous I/O request associated with the aiocb structure pointed to by aiocbp. 

aio_return() should be called only once to retrieve the valid return status of a given asynchronous operation, after aio_error() has returned a value other than
EINPROGRESS.

RETURN VALUES

If the asynchronous I/O operation has completed successfully, aio_return() returns the return status, as described for read(2), write(2), and fsync(3C). 

If the asynchronous I/O operation has completed successfully, aio_error() returns 0.  If the operation has not yet completed, then EINPROGRESS is returned.  If the asynchronous I/O operation has completed unsuccessfully, then the error status, as described for read(2), write(2), and fsync(3C) is returned. 

If unsuccessful, aio_return() or aio_error() return -1, and set errno to indicate the error condition. 

ERRORS

EINVAL aiocbp does not reference an asynchronous operation which has completed or failed. 

ENOSYS aio_return() or aio_error() is not supported by this implementation. 

EXAMPLES

#include <aio.h>
#include <errno.h>
#include <signal.h>
struct aiocbmy_aiocb;
struct sigactionmy_sigaction;
voidmy_aio_handler(int, siginfo_t ∗, void ∗);
...
my_sigaction.sa_flags = SA_SIGINFO;
my_sigaction.sa_sigaction = my_aio_handler;
sigsetempty(&my_sigaction.sa_mask);
(void) sigaction(SIGRTMIN, &my_sigaction, NULL);
...
my_aiocb.aio_sigevent.sigev_notify = SIGEV_SIGNAL;
my_aiocb.aio_sigevent.sigev_signo = SIGRTMIN;
my_aiocb.aio_sigevent.sigev_value.sival_ptr = &myaiocb;
...
(void) aio_read(&my_aiocb);
...

void
my_aio_handler(int signo, siginfo_t ∗siginfo, void ∗context) {
intmy_errno;
struct aiocb∗my_aiocbp;

my_aiocbp = siginfo.si_value.sival_ptr;
if ((my_errno = aio_error(my_aiocb)) != EINPROGRESS) {
intmy_status = aio_return(my_aiocb);
if (my_status >= 0) {/∗ start another operation ∗/
...
} else{ /∗ handle I/O error ∗/
...
}
}
}

SEE ALSO

close(2), exec(2), exit(2), fork(2), lseek(2), read(2), write(2), fsync(3C), aio_cancel(3R), aio_fsync(3R), aio_read(3R), lio_listio(3R)

NOTES

Applications compiled under Solaris 2.3 and 2.4 and using POSIX aio must be recompiled to work correctly when Solaris supports the Asynchronous Input and Output option. 

BUGS

In Solaris 2.5, these functions always return −1 and set errno to ENOSYS, because this release does not support the Asynchronous Input and Output option.  It is our intention to provide support for these interfaces in future releases. 

SunOS 5.5.1  —  Last change: 19 Aug 1993