#include <nng/nng.h> void nng_aio_wait(nng_aio *aio);
nng_aio_wait - wait for asynchronous I/O operation
nng_aio_wait() function waits for an asynchronous I/O operation
If the operation has not been started, or has already
completed, then it returns immediately.
If the a callback was set with aio when it was allocated, then this function will not be called until the callback has completed.