nng_aio_set_iov − set scatter/gather vector
#include <nng/nng.h>
int nng_aio_set_iov(nng_aio *aio, unsigned int niov, nng_iov *iov);
The nng_aio_set_iov() function sets a scatter/gather vector iov on the handle aio.
The iov is a pointer to an array of niov nng_iov structures, which have the following definition:
typedef struct
nng_iov {
void * iov_buf;
size_t iov_len;
};
The iov is copied into storage in the aio itself, so that callers may use stack allocated nng_iov structures. The values pointed to by the iov_buf members are not copied by this function though.
A maximum of four (4) nng_iov members may be supplied.
Note
Earlier versions of the library could accept longer scatter−gather lists. However, no known consumers have ever needed a scatter−gather list longer than 4 vectors. As a result, the implementation limit was reduced, and heap allocations which could fail were removed.
This function returns 0 on success, and non−zero otherwise.
NNG_EINVAL
Value of specified niov is too large.
nng_aio_alloc(3), nng_aio_cancel(3), nng_aio_count(3), nng_aio_result(3), nng_aio(5), nng_iov(5), nng(7)