[RFC] async source3/rpc_server

[Volker Lendecke]

On Tue, Apr 24, 2012 at 03:37:59PM +0200, David Disseldorp wrote:
> In order to properly implement a File Server Remote Shadow-copy Protocol
> (MS-FSRVP) RPC server, snapshot/shadow-copy operations should be handled
> asynchronously from PDU processing through to VFS request dispatch.
> 
> Working towards this, I've made a some small changes to carry two types
> of RPC server command arrays (synchronous and asynchronous) under
> api_struct. See pull request at the bottom of this mail.
> 
> IDLs are flagged sync or async at build time, with sync builds compiling
> into the existing interface via Pidl/Samba3/ServerNDR.pm:
>   struct api_struct_sync {
>           const char *name;
>           uint8 opnum;
>           bool (*fn) (struct pipes_struct *);
>   };
> 
> Async builds will compile into send/recv hooks with a new
> --samba3-ndr-server-async pidl option:
>   struct api_struct_async {
>           const char *name;
>           uint8 opnum;
>           struct tevent_req *(*fn_send)(TALLOC_CTX *,
>                                         struct tevent_context *,
>                                         struct pipes_struct *);
>           NTSTATUS (*fn_recv)(struct tevent_req *);
>   };
> 
> Existing synchronous server IDL will remain so for the time being.
> The same code path will be shared between sync and async backends
> up to the point of gen_ndr srv dispatch. i.e. api_rpcTNP for
> rpc_server/srv_pipe.c.
> 
> Does this approach sound sane?

Yes, that looks sane to me. As fallbacks, can we
autogenerate sync/async wrappers? I have not yet fully
thought out the complete picture, but I could imagine that
we make the normal RPC server infrastructure completely
async and then for the sync backends autogenerate fake async
wrappers calling into the sync functions.

Volker

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