To use those functions, you must have *libminiasync* installed. Those functions use futures
and vdm (virtual data mover) concepts from this library. Please check **miniasync**(7) for more details.
The struct **pmem2_future** is a structure describing a task to be done asynchronously taking into account persistence
of the operation. It means that by the time the future is complete, all the data is safely written into a persistent domain.
The **pmem2_config_set_vdm** sets a vdm structure in the *pmem2_config*.
This structure will be used by pmem2_*_async functions, to create a *vdm_operation_future*.
This structure will be used by pmem2_*_async functions, to create a *pmem2_future*.
If vdm is not set in the config, pmem2_map_new will use a default one which uses a
pmem2 memory movement functions to perform memory operations. (**pmem2_get_memcpy_fn**(3), **pmem2_get_memmove_fn**(3), **pmem2_get_memsety_fn**(3)).
pmem2 memory movement functions to perform memory operations. (**pmem2_get_memcpy_fn**(3), **pmem2_get_memmove_fn**(3), **pmem2_get_memset_fn**(3)).
The **pmem2_memcpy_async** uses *vdm* structure held inside the *pmem2_map* structure to initialise and returns **vdm_operation_future**.
The **pmem2_memcpy_async** uses *vdm* structure held inside the *pmem2_map* structure to initialise and returns **pmem2_future**.
This future will perform memcpy operation defined in *vdm* to copy *len* bytes from *src* to *pmemdest*. In the current implementation *flags* are ignored.
The **pmem2_memmove_async** returns **vdm_operation_future** which
The **pmem2_memmove_async** returns **pmem2_future** which
will perform memmove operation defined in *vdm* to copy *len* bytes from *src* to *pmemdest*. In the current implementation *flags* are ignored.
The **pmem2_memmset_async** returns **vdm_operation_future** which
The **pmem2_memset_async** returns **pmem2_future** which
will perform memset operation defined in *vdm* to fill *n* bytes from *pmemstr* with value of int *c* interpreted as unsigned char.
In the current implementation *flags* are ignored.
# RETURN VALUE #
The **pmem2_config_set_vdm** always return 0.
The **pmem2_memcpy_async** returns a new instance of **vdm_operation_future** performing memcpy operation.
The **pmem2_memcpy_async** returns a new instance of **pmem2_future** performing memcpy operation.
You can execute returned structure using methods from the **libminiasync**() library such as **FUTURE_BUSY_POLL**(3).
The **pmem2_memmove_async** returns a new instance of **vdm_operation_future** performing memmove operation.
The **pmem2_memmove_async** returns a new instance of **pmem2_future** performing memmove operation.
The **pmem2_memset_async** returns a new instance of **vdm_operation_future** performing memset operation.
The **pmem2_memset_async** returns a new instance of **pmem2_future** performing memset operation.
