[vwnc] Question about procesess

> -----Original Message-----
> From: [hidden email] [mailto:[hidden email]] On Behalf Of Andres Fortier
> Sent: Friday, November 21, 2008 12:33 PM
> To: VWNC List
> Subject: [vwnc] Question about procesess
>
> Hi list,
>             I have a typical situation of getting
> data/processing/sending data, running in a constant loop. Both the
> input and output are done via sockets. The code looks something like:
>
>
> MyClass>>step
>
> | data result |
>
> data:=self input readData.
> result:=self process: data.
> self output send: result.
>
>
> where readData uses at some place something like:
>
> self socket readWait.
>
> Now, I would like to add some sort of play/stop functionality. I've
> seen that I can fork a process that constantly calls #step and store
> the process in an inst var, so I can later send something like
> #terminate to it. However there are two issues that I'm not sure about:
>
> 1. I know that if I send the #terminate message while the process is
> in the socket's #readWait, the process actually stops; what I would
> like to know is if this is safe in terms of the socket (i.e. if I'm
> not eaving something at the vm or os level in an inconsistent state).
> 2. If the data has already been read from the socket I would like the
> step to end (i.e. the data processing and the send to be completed,
> kind of a transaction). Is there any simple way of handling this?
>
> Thanks in advance,
> Andrés
> _______________________________________________
> vwnc mailing list
> [hidden email]
> http://lists.cs.uiuc.edu/mailman/listinfo/vwnc

> Andres
>
> If you look at IOAccessor>>readWaitWithTimeoutMs: you will
> see that the Delay shares the read semaphore. So, when
> the delay signals the semaphore the read process will awaken.
>
> You can do something similar. When you want to terminate
> you set a terminate flag then signal the semaphore. The
> read process then reads whatever is there and continues
> the read loop, which checks the terminate flag at the
> end of the read processing.
>
> Terry
>  
> ===========================================================
> Terry Raymond
> Crafted Smalltalk
> 80 Lazywood Ln.
> Tiverton, RI  02878
> (401) 624-4517      [hidden email]
> <http://www.craftedsmalltalk.com>
> ===========================================================
>
>> -----Original Message-----
>> From: [hidden email] [mailto:[hidden email]] On Behalf Of Andres Fortier
>> Sent: Friday, November 21, 2008 12:33 PM
>> To: VWNC List
>> Subject: [vwnc] Question about procesess
>>
>> Hi list,
>>             I have a typical situation of getting
>> data/processing/sending data, running in a constant loop. Both the
>> input and output are done via sockets. The code looks something like:
>>
>>
>> MyClass>>step
>>
>> | data result |
>>
>> data:=self input readData.
>> result:=self process: data.
>> self output send: result.
>>
>>
>> where readData uses at some place something like:
>>
>> self socket readWait.
>>
>> Now, I would like to add some sort of play/stop functionality. I've
>> seen that I can fork a process that constantly calls #step and store
>> the process in an inst var, so I can later send something like
>> #terminate to it. However there are two issues that I'm not sure about:
>>
>> 1. I know that if I send the #terminate message while the process is
>> in the socket's #readWait, the process actually stops; what I would
>> like to know is if this is safe in terms of the socket (i.e. if I'm
>> not eaving something at the vm or os level in an inconsistent state).
>> 2. If the data has already been read from the socket I would like the
>> step to end (i.e. the data processing and the send to be completed,
>> kind of a transaction). Is there any simple way of handling this?
>>
>> Thanks in advance,
>> Andrés
>> _______________________________________________
>> vwnc mailing list
>> [hidden email]
>> http://lists.cs.uiuc.edu/mailman/listinfo/vwnc
>
>