aio_error

- retrieve errors status for an asynchronous I/O operation

Synopsis

#include <aio.h>

int aio_error(const struct aiocb *aiocbp);

Description

The aio_error() function returns the error status associated with the aiocb structure referenced by the aiocbp argument. The error status for an asynchronous I/O operation is the errno value that would be set by the corresponding read(2), write(2), or fsync(3C) operation. If the operation has not yet completed, then the error status will be equal to EINPROGRESS.

Return Values

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

Errors

The aio_error() function may fail if:

EINVAL

The aiocbp argument does not refer to an asynchronous operation whose return status has not yet been retrieved.

Usage

The aio_error() function has a transitional interface for 64-bit file offsets. See lf64(5).

Examples

Example 1 The following is an example of an error handling routine using the aio_error() function.

#include <aio.h>
#include <errno.h>
#include <signal.h>
struct aiocb      my_aiocb;
struct sigaction  my_sigaction;
void              my_aio_handler(int, siginfo_t *, void *);
 . . .
my_sigaction.sa_flags = SA_SIGINFO;
my_sigaction.sa_sigaction = my_aio_handler;
sigemptyset(&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) {
int    my_errno;
struct aiocb    *my_aiocbp;

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

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

_Exit(2), close(2), fork(2), lseek(2), read(2), write(2), aio.h(3HEAD), aio_cancel(3C), aio_fsync(3C), aio_read(3C), aio_return(3C), aio_write(3C), lio_listio(3C), signal.h(3HEAD), attributes(5), lf64(5), standards(5)