nn_allocmsg(3) ============== NAME ---- nn_allocmsg - allocate a message SYNOPSIS -------- *#include * *void *nn_allocmsg (size_t 'size', int 'type');* DESCRIPTION ----------- Allocate a message of the specified 'size' to be sent in zero-copy fashion. The content of the message is undefined after allocation and it should be filled in by the user. While linknanomsg:nn_send[3] and linknanomsg:nn_sendmsg[3] allow to send arbitrary buffers, buffers allocated using _nn_allocmsg()_ can be more efficient for large messages as they allow for using zero-copy techniques. 'type' parameter specifies type of allocation mechanism to use. Zero is the default one, however, individual transport mechanisms may define their own allocation mechanisms, such as allocating in shared memory or allocating a memory block pinned down to a physical memory address. Such allocation, when used with the transport that defines them, should be more efficient than the default allocation mechanism. RETURN VALUE ------------ If the function succeeds pointer to newly allocated buffer is returned. Otherwise, NULL is returned and 'errno' is set to to one of the values defined below. ERRORS ------ *EINVAL*:: Supplied allocation 'type' is invalid. *ENOMEM*:: Not enough memory to allocate the message. EXAMPLE ------- ---- void *buf = nn_allocmsg (12, 0); memcpy (buf, "Hello world!", 12); nn_send (s, &buf, NN_MSG, 0); ---- SEE ALSO -------- linknanomsg:nn_freemsg[3] linknanomsg:nn_reallocmsg[3] linknanomsg:nn_send[3] linknanomsg:nn_sendmsg[3] linknanomsg:nanomsg[7] AUTHORS ------- Martin Sustrik