This documentation is for version v1.3.0 of NNG, but the latest released version is v1.8.0. see the documentation for v1.8.0 for the most up-to-date information.


#include <nanomsg/nn.h>

void *nn_allocmsg(size_t size, int type);


The nn_allocmsg() allocates a message structure of size size, and is primarily used to support zero-copy send operations, making use of the NNG_MSG special size indicator. The value returned is a pointer to the start of the message payload buffer.

The value of size must be positive, and small enough to hold reasonable message data plus book-keeping information.

This function is provided for API compatibility with legacy libnanomsg. Consider using the relevant modern API instead.

The value of type must be zero. (This argument was reserved to support different kinds of memory spaces for RDMA devices, but this was never developed in the legacy API.)

The returned message must be disposed of by either nn_freemsg() or nn_send() when the caller is finished with it.


This function returns a pointer to message buffer space, or NULL on failure.



Insufficient memory is available.


An invalid size or type was specified.


The library is shutting down.