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 {

 int                  aio_fildes;        /* file descriptor * /
 volatile void        * aio_buf;        /* buffer location * /
 size_t               aio_nbytes;       /* length of transfer * /
 off_t                aio_offset;       /* file offset * /
 int                  aio_reqprio;      /* request priority offset * /
 struct sigevent      aio_sigevent;     /* signal number and offset * /
 int                  aio_lio_opcode; /* listio operation * /
};

struct sigevent {

 int                  sigev_notify;     /* notification mode * /
 int                  sigev_signo;      /* signal number * /
 union sigval         sigev_value;      /* signal value * /
};

union sigval {

 int                  sival_int;        /* integer value * /
 void                 * sival_ptr;      /* pointer value * /
};

MT-LEVEL

Async-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 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;
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){
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 * /
                     . . .
             }
     }
}

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)

BUGS

In Solaris 2.4, 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.