[squeak-dev] Distributing network load using HydraVM

> My head just visited another idea, and i'd like to share it :)
>
> There was a discussion on how to pass sockets between images safely.
> And due to reasons that it's not safe, not easy, and require a lot
> changes which may break compatibility, solution was postponed for a
> future.
>
> Now, i think i found the way how to pass the newly created socket to
> another image by using a special accept primitive.
>
> What this primitive should do:
>
> by taking parameters: interpreter handle, socket handle and channel
> name, it should
> 1. do validity checks (all handles should be valid e.t.c)
> 2. accept new incoming socket connection (socket handle passed to
> primitive should be in listen mode)

> 3. if system fails with accept(), primitive fails
> 4. create an event and put new socket handle , and channel name to it.
> 5. enqueue given event to target interpreter event queue.
> --
>
> Event handling:
> - register socket handle in SocketPlugin internal structures.
> - then find channel with given name, and put SocketHandle bytearray as  
> packet.
>
> voila..
>
> Now at language side, you simply need a channel, which listening for
> packets, containing socket handles.
> Once packet received, you know, that it's newly accepted socket
> connection and can do anything you want with it.
>
> ............
> by finishing writing this, i just thought that passing ownership of
> already open socket can be done in similar way:
> a primitive can remove given socket from SocketPlugin internal
> structures and pass it with event to another interpreter.
>

> On Tue, 26 Feb 2008 04:51:56 +0100, Igor Stasenko wrote:
>
>  > My head just visited another idea, and i'd like to share it :)
>  >
>  > There was a discussion on how to pass sockets between images safely.
>  > And due to reasons that it's not safe, not easy, and require a lot
>  > changes which may break compatibility, solution was postponed for a
>  > future.
>  >
>  > Now, i think i found the way how to pass the newly created socket to
>  > another image by using a special accept primitive.
>  >
>  > What this primitive should do:
>  >
>  > by taking parameters: interpreter handle, socket handle and channel
>  > name, it should
>  > 1. do validity checks (all handles should be valid e.t.c)
>  > 2. accept new incoming socket connection (socket handle passed to
>  > primitive should be in listen mode)
>
>
> Does your 2. correspond to the line I marked in the following?:
>
>  | localhost serverSocket clientSocket sessionSocket listener |
>   localhost := NetNameResolver localHostAddress.
>   serverSocket := Socket newTCP listenOn: 7680 backlogSize: 1.
>   listener := [serverSocket waitForConnectionFor: 0.5
>         ifTimedOut: [Transcript cr; show: 'timed out ',
>         serverSocket statusString]]
>     forkAt: Processor activeProcess priority.
>   clientSocket := Socket newTCP connectTo: localhost port: 7680.
>   (Delay forMilliseconds: 250) wait.
>  "marked" sessionSocket := serverSocket accept.
>   Transcript cr; show: '[server] ', serverSocket statusString;
>         cr; show: '[session] ', sessionSocket statusString;
>         cr; show: '[client] ', clientSocket statusString;
>         cr; show: 'listener: ', listener browserPrintString; cr.
>   serverSocket destroy.
>   clientSocket destroy.
>   sessionSocket destroy
>
>  You mean, the marked line would be done by the new primitive, the accepted
>  Socket then passed to another HydraVM instance (err, interpreter, via
>  channel)?! That would allow "workers" run on their own CPU :)
>