HP-UX Reference (11i v2 04/09) - 2 System Calls (vol 5)

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lio_listio(2) lio_listio(2)

ERRORS

If lio_listio() detects one of the following error conditions,

errno is set to the indicated value:

[EAGAIN]

At least one request could not be queued either because of a resource shortage or because

the per-process or system-wide limit on asynchronous I/O operations or asynchronous

threads would have been exceeded.

[EINTR] The mode argument was

LIO_WAIT and a signal was delivered while waiting for the

requested operations to complete. This signal may result from completion of one or more

of the requested operations and other requests may still be pending or completed.

[EINVAL] The

sigevent speciﬁed by sig is not valid.

[EINVAL] The mode argument is neither

LIO_WAIT nor LIO_NOWAIT.

[EINVAL] The value of the nent argument is negative or greater than the maximum value allowed.

The maximum value allowed can be obtained using the

sysconf() call with the argu-

ment

_SC_AIO_LISTIO_MAX

Once an operation has been enqueued by

lio_listio(), the following errors, in addition to all of the

errors normally reported by the appropriate

read()

or write() function, may be reported asynchro-

nously by a subsequent call to

aio_error() or

aio_return() referencing its aiocbp.

[EBADF] The

aiocbp->aio_fildes was not a valid ﬁle descriptor open for reading or writing

as appropriate to the aio_lio_opcode

[EINVAL] The value of

aiocbp->aio_reqprio

is not valid, or the value of

aiocbp->aio_nbytes is invalid, or the ﬁle offset implied by

aiocbp->aio_offset or aiocbp->aio_offset+aiocbp->aio_nbytes is not

valid.

[EIO] One or more of the enqueued operations did not complete successfully.

EXAMPLES

The following code sequence and call to lio_listio() starts two asynchronous write operations and

one asynchronous read operation and waits for all operations to complete.

#include <fcntl.h>

#include <errno.h>

#include <aio.h>

char buf1[4096], buf2[4096], buf3[4096];

int nent;

struct aiocb myaiocb1, myaiocb2, myaiocb3;

struct aiocb *list[] = { &myaiocb1, &myaiocb2, &myaiocb3 };

bzero( &myaiocb1, sizeof (struct aiocb));

bzero( &myaiocb2, sizeof (struct aiocb));

bzero( &myaiocb3, sizeof (struct aiocb));

myaiocb1.aio_fildes = open( "/dev/null", O_RDWR);

myaiocb3.aio_fildes = myaiocb2.aio_fildes = myaiocb1.aio_fildes;

myaiocb1.aio_offset = 0;

myaiocb3.aio_offset = myaiocb2.aio_offset = myaiocb1.aio_offset;

myaiocb1.aio_buf = (void *) buf1;

myaiocb2.aio_buf = (void *) buf2;

myaiocb3.aio_buf = (void *) buf3;

myaiocb3.aio_nbytes = sizeof (buf3);

myaiocb2.aio_nbytes = sizeof (buf2);

myaiocb1.aio_nbytes = sizeof (buf1);

myaiocb1.aio_lio_opcode = myaiocb3.aio_lio_opcode = LIO_WRITE;

myaiocb2.aio_lio_opcode = LIO_READ;

myaiocb1.aio_sigevent.sigev_notify = SIGEV_NONE;

myaiocb2.aio_sigevent.sigev_notify = SIGEV_NONE;

myaiocb3.aio_sigevent.sigev_notify = SIGEV_NONE;

retval = lio_listio( LIO_WAIT, list, 3, NULL );

if (retval) perror("lio_listio:");

while ( nent-- ) { (void) aio_return( list[nent] ); }

Section 2−−136 Hewlett-Packard Company − 2 − HP-UX 11i Version 2: September 2004