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 <nng/nng.h>

bool nng_aio_begin(nng_aio *aio);


The nng_aio_begin() function is called by the I/O provider to indicate that it is going to process the operation.

The function may return false, indicating that the aio has been closed by the caller asynchronously. In this case the provider should abandon the operation and do nothing else.

This operation should be called at the start of any I/O operation, and must be called not more than once for a given I/O operation on a given aio.

Once this function is called, if true is returned, then the provider MUST guarantee that nng_aio_finish() is called for the aio exactly once, when the operation is complete or canceled.

This function is only for I/O providers (those actually performing the operation such as HTTP handler functions or transport providers); ordinary users of the aio should not call this function.



The operation has been started.


The operation cannot be started.