[Coco] signal/intercept routine in Basic09

Aaron Wolfe aawolfe at gmail.com
Sun Jan 24 01:02:13 EST 2010


It's probably worth mentioning that this technique is not appropriate
for catching lots of signals coming in quickly.  If 2 or more signals
occur before the b09 program reads the signal variable, or if signals
occur between when it reads and when it resets to 0, they will be
missed.  This is not a problem for our current application, but might
be for more complicated projects.
-Aaron

On Sun, Jan 24, 2010 at 12:57 AM, Bob Devries <devries.bob at gmail.com> wrote:
> Which code effectively does this:
>
> STB 00,U
> RTI
>
> Thanks, Aaron. You da man!
>
> --
> Besides a mathematical inclination, an exceptionally good mastery of one's
> native tongue is the most vital asset of a competent programmer.
>
> Edsger W.Dijkstra, 18 June 1975
>
> ----- Original Message ----- From: "Wayne Campbell" <asa.rand at gmail.com>
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Sent: Sunday, January 24, 2010 4:50 PM
> Subject: Re: [Coco] signal/intercept routine in Basic09
>
>
>> Aaron Wolfe came up with a signal handler for Basic09, and it works. I
>> tested it myself. When you run it, use another window to type send -<signal>
>> <proc> where signal is the number and proc is the process.
>>
>> Wayne
>>
>> example:
>>
>> PROCEDURE testsig
>> TYPE REG=cc,a,b,dp:BYTE; x,y,u:INTEGER
>> DIM regs:REG
>> DIM sigHandler(3),callCode,signal:BYTE
>> sigHandler(1):=231
>> sigHandler(2):=196
>> sigHandler(3):=59
>> callCode:=$09
>> regs.x:=ADDR(sigHandler)
>> regs.u:=ADDR(signal)
>> RUN SysCall(callCode,regs)
>> LOOP
>> EXITIF signal=3 THEN
>> ENDEXIT
>> IF signal>0 THEN
>> PRINT signal
>> signal:=0
>> ENDIF
>> ENDLOOP
>> END
>>
>> ----- Original Message ----- From: "Bob Devries" <devries.bob at gmail.com>
>> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
>> Sent: Saturday, January 23, 2010 9:20 PM
>> Subject: Re: [Coco] signal/intercept routine in Basic09
>>
>>
>>> I'm wondering if the ON ERROR GOTO in Basic09 only handles errors
>>> generated by the Basic09 interpreter, but not those which come from an
>>> external source?
>>>
>>> --
>>> Besides a mathematical inclination, an exceptionally good mastery of
>>> one's native tongue is the most vital asset of a competent programmer.
>>>
>>> Edsger W.Dijkstra, 18 June 1975
>>>
>>> ----- Original Message ----- From: "Aaron Wolfe" <aawolfe at gmail.com>
>>> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
>>> Sent: Sunday, January 24, 2010 3:19 PM
>>> Subject: Re: [Coco] signal/intercept routine in Basic09
>>>
>>>
>>> Are signals really equivalent to errors?  That doesn't seem right.  Or
>>> is this a Basic09 thing?
>>> Signals can happen for many "non error" reasons, for instance a Wake
>>> signal often means a very normal, non error condition.  In the case at
>>> hand, the  "other end hung up" signal is sort of an error I guess, but
>>> it's not an OS9 error like read or write errors are.
>>>
>>> as I understand it, os9 'sends' a signal by calling the routine at the
>>> address stored in the P$SigVec field of the process descriptor.  Does
>>> Basic09 automatically put a routine here that turns a signal into an
>>> error that will trip the ON ERROR of a running program?
>>>
>>>
>>> On Sat, Jan 23, 2010 at 11:02 PM, Wayne Campbell <asa.rand at gmail.com>
>>> wrote:
>>>>
>>>> Apparently, ON ERROR GOTO doesn't like 4. I opened a window, ran a test
>>>> prog
>>>> that just ran a loop and reacted to ON ERROR GOTO. When I sent the
>>>> signal 4
>>>> to the process from the other window (used send -1 <proc>), Basic09
>>>> dropped
>>>> into debug instead of going thru the error trap.
>>>>
>>>> Wayne
>>>>
>>>> ----- Original Message ----- From: "Christopher Hawks" <chawks at dls.net>
>>>> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
>>>> Sent: Saturday, January 23, 2010 7:36 PM
>>>> Subject: Re: [Coco] signal/intercept routine in Basic09
>>>>
>>>>
>>>>> Wayne Campbell said the following on 01/23/2010 07:59 PM:
>>>>>>
>>>>>> This sounds like a modification to the way drivewire sends signals?
>>>>>
>>>>> Standard OS9 signaling. Drivewire sends a Hangup signal.
>>>>>
>>>>> lda P$ID,x Process to send to
>>>>> ldb #S$HUP Signal to send ( 4 )
>>>>> os9 F$Send doit
>>>>>
>>>>>> ----- Original Message ----- From: "Robert Gault"
>>>>>> <robert.gault at worldnet.att.net>
>>>>>> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
>>>>>> Sent: Saturday, January 23, 2010 5:52 PM
>>>>>> Subject: Re: [Coco] signal/intercept routine in Basic09
>>>>>>
>>>>>>
>>>>>>> Aaron Wolfe wrote:
>>>>>>>>
>>>>>>>> It's probably worth noting that the "port closed" signal is not a
>>>>>>>> part
>>>>>>>> of standard OS-9, it is a feature of the DriveWire additions we're
>>>>>>>> working on. The signal's value is 4. It is sent to a process when
>>>>>>>> the remote end of a TCPIP connection closes.
>>>>>>>>
>>>>>>>
>>>>>>> For what it is worth, Basic09 would trap the error 4.
>>>>>>> ON ERROR GOTO 100
>>>>>>> ERROR 4
>>>>>>> END
>>>>>>> 100 PRINT"The error was caught."
>>>>>>>
>>>>>>> When this is run, the message is printed. Now the manual indicates
>>>>>>> that
>>>>>>> there is no real difference between signals and errors. Errors are
>>>>>>> just
>>>>>>> specific signals. So, if the signal to be caught is coming from
>>>>>>> Drivewire,
>>>>>>> it does not seem to be getting through to Basic09. That's assuming
>>>>>>> error
>>>>>>> trapping as above is being used.
>>>>>>>
>>>>>>> It may mean that using syscall to set up an intercept may not work
>>>>>>> either.
>>>>>>>
>>>>>>> --
>>>>>>> Coco mailing list
>>>>>>> Coco at maltedmedia.com
>>>>>>> http://five.pairlist.net/mailman/listinfo/coco
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Coco mailing list
>>>>>> Coco at maltedmedia.com
>>>>>> http://five.pairlist.net/mailman/listinfo/coco
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Christopher R. Hawks
>>>>> HAWKSoft
>>>>> ---------------------------------------------------------
>>>>> "The reasonable man adapts himself to the world: the unreasonable one
>>>>> persists in trying to adapt the world to himself. Therefore all
>>>>> progress
>>>>> depends on the unreasonable man."
>>>>> -- George Bernard Shaw
>>>>>
>>>>> --
>>>>> Coco mailing list
>>>>> Coco at maltedmedia.com
>>>>> http://five.pairlist.net/mailman/listinfo/coco
>>>>
>>>>
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