#include <nng/nng.h>
#include <nng/supplemental/util/platform.h>
typedef struct nng_mtx nng_mtx;
int nng_mtx_alloc(nng_mtx **mtxp);The nng_mtx_alloc() function allocates mutex and returns it in mtxp.
The mutex objects created by this function are suitable only for simple lock and unlock operations, and are not recursive. Every effort has been made to use light-weight underlying primitives when available.
Mutex (mutual exclusion) objects can be thought of as binary semaphores, where only a single thread of execution is permitted to “own” the semaphore.
Furthermore, a mutex can only be unlocked by the thread that locked it.