lio_listio.2 (2010 09)

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lio_listio(2) lio_listio(2)

asynchronous threads would have been exceeded.

[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 argument

_SC_AIO_LISTIO_MAX

[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 com-

pleted.

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

aiocbp->aio_offset

+aiocbp->aio_nbytes is not valid.

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

EXAMPLE

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] ); }