Re: TASK HALT with another task

Hi ,

>> > > A task could execute the STOP instruction within itself to stop.
>
>Yes, that is how a task deactivates itself. However, once STOPped
>it cannot start up again on its own; it needs to be started by another
>task.

I though this was only for a task with transitient behavior.

>>...
>> > : READSWITCHES
>> >
>> > PIND C@ 254 =
>> > IF TESTER HALT
>> > ELSE PIND C@ 253 =
>> > IF TESTER ACTIVATE
>>
>>You can't have an activate without anything following it. Where is your
>>endless loop? I think you mean:
>> > IF TESTER ACTIVATE SEQBITFLASH
>>
>> > THEN
>> > THEN ;
>
>Noel is right, ACTIVATE needs to be followed by the code the
>task is supposed to execute.

The code as I wrote is with two tasks works and works well(see below).
As soon as I add something after TESTER ACTIVATE
in the REASSWITCHES word, then it doesn't work anymore.
Why then does it work so good? I can't be by chance, can it?

It does exactly what I want, that is flashing stops
when pressing switch 0 and restarts
when pressing switch 1.
I don't even have to keep the
switch buttons pressed.
The only thing I didn't succeed in doing is
to start up the the tester task with the SEQBITFLASH
without flashing.
Is there not a trick to do it working
with the the code I have already? (see below).
Replacing the IF-THEN structures by vectored
execution is also error prone and though I
tried it out, it doesn't work as well as this
code with two tasks.

TARGET

|U| |S| |R| BACKGROUND TESTER

|U| |S| |R| BACKGROUND TESTER2

: READSWITCHES
    PIND C@ 254 =
          IF TESTER HALT
              ELSE PIND C@ 253 =
                IF TESTER ACTIVATE
                THEN
          THEN ;

 : SEQBITFLASH ( -- )
       1
        BEGIN
          PORTB C@ 2DUP SWAP - AND
          PORTB C! 100 MS 2*
          PORTB C@ 127 = IF DROP 1
                          THEN
           255 PORTB C! 100 MS
         AGAIN ; \ For in task
          
           

: /TESTER ( -- )
    $FF DDRB C! \ Set PORTB as OUTPUT
    $FF PORTB C! \ set leds off at start up
    TESTER BUILD TESTER ACTIVATE
       BEGIN PAUSE
        
            SEQBITFLASH
                     
       AGAIN ;

: /TESTER2 ( -- )
   TESTER2 BUILD TESTER2 ACTIVATE
   BEGIN PAUSE READSWITCHES
                 
   AGAIN ;

Thanks in advance,
Viviane

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Received on Sun Aug 10 2003 - 12:11:03 PDT