llvm dev - Mar 2006 - [LLVMdev] Researching alternative for home-grown VM

I'm researching an alternative to our home-grown VM that is used for a
telecomm system.  LLVM sounds like it fits the bill... however, one of the
primary reasons for developing our home-grown VM was the concept of
continuation.

Basically, the code that folks write can call certain built-in functions of
our "language".  These functions cause the VM to stop execution and
save a
"context".  Later on an event arriving at the VM and pick up the
context,
and continue execution of the code.

=> Is there a way to do this LLVM (i.e has anyone done this or something
similar)?
=> If not, can I implement it as a new op-code?  We basically have
implemented a "WAIT" opcode in our VM, which tells it to stop
execution of
this code, and wait for external events.

Let met give a more concrete example:

The code may say:

      status = sql_exec("Server1", Timeout, "select subscriberid
from
tblSubscriber where ANI='"+ani+"';", subscriberid);

In this case, the sql_exec() is a built-in function of our language which
sends a DB query, and then issues a "WAIT".  This allows the VM to
then
process another event which may execute some completely un-related code.
Then when a db-response event arrives, since there is a mapping for that
event, it will then startup processing of the sql_exect() at the point
where it had issued the WAIT.

Thanks & Regards,

Renny Koshy
President & CEO

--------------------------------------------
RUBIX Information Technologies, Inc.
www.rubixinfotech.com

On Tue, 7 Mar 2006 renny.koshy at rubixinfotech.com
wrote:
> I'm researching an alternative to our home-grown VM that is used for a
> telecomm system.  LLVM sounds like it fits the bill... however, one of the
> primary reasons for developing our home-grown VM was the concept of
> continuation.
ok
> Basically, the code that folks write can call certain built-in functions of
> our "language".  These functions cause the VM to stop execution
and save a
> "context".  Later on an event arriving at the VM and pick up the
context,
> and continue execution of the code.
ok.
> => Is there a way to do this LLVM (i.e has anyone done this or something
> similar)?
Nope, not that I know of.
> => If not, can I implement it as a new op-code?  We basically have
> implemented a "WAIT" opcode in our VM, which tells it to stop
execution of
> this code, and wait for external events.
How would this be implemented?  Could you just insert a call to wait() and 
have the implementation do the right thing?
> Let met give a more concrete example:
>
> The code may say:
>
>      status = sql_exec("Server1", Timeout, "select
subscriberid from
> tblSubscriber where ANI='"+ani+"';", subscriberid);
>
> In this case, the sql_exec() is a built-in function of our language which
> sends a DB query, and then issues a "WAIT".  This allows the VM
to then
> process another event which may execute some completely un-related code.
> Then when a db-response event arrives, since there is a mapping for that
> event, it will then startup processing of the sql_exect() at the point
> where it had issued the WAIT.
Sure, this seems straight-forward.  I would suggest just using an external 
function call to do this.

-Chris

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