NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/sys/amiga/programmer/6171

Internet Message Format | 1996-08-05 | 3.5 KB

Path: god.bel.alcatel.be!nlev00!barnhoorn
From: barnhoorn@nlev00 ()
Newsgroups: comp.sys.amiga.programmer
Subject: Re: Removing Processes
Date: 25 Mar 1996 12:07:03 GMT
Organization: Alcatel Bell
Distribution: world
Message-ID: <4j6297$[e-mail]>
References: <[e-mail]> <[e-mail]>
Reply-To: barnhoorn@nlev00 ()
NNTP-Posting-Host: 138.203.178.61
X-Newsreader: mxrn 6.18-10


In article <[e-mail]>, Avi Lev <[e-mail]> writes:
>Dave Thomas wrote:
>>
>> Hi!  I'm writing a program which spawns a sub-process to do another task
>> while the main program handles input.  The problem I'm finding is that the
>> sub-process doesn't exit reliably.  Sometimes it appears to exit, and
>> sometimes not.  Currently, I am allowing the subprocess to run to the end,
>> when (I assume) it does an "RTS" and returns to the OS for removal. Should
>> I be using "RemTask()" to remove the sub-process?  And, if so, should it be
>> called from the sub-process, or from the main program?  BTW, the
>> sub-process is a procedure in the program, and uses some global variables
>> and string constants.
>
>NO!!! RemTask() removes tasks not processes. how do you know if the sub-process actually finished, it
>might be suspended cuz of higher priority process. i think there's a wait() function which checks to
>see if the process finished and if not it waits until it does, you might want to go in that direction
>first. what you're describing sounds like it's a task NOT a real AmigaDos process cuz the 'process'
>sits in your own program, if that's the case then it's a task not a process and then you can use
>RemTask() from the creator of the task.

## AAAHHH wrong wrong wrong wrong.
You may either run parts of your application as a process or as a task.
For running a part of your application as a process, use CreateNewProc().
For running a part of your application as a task, use CreateTask().
I suggest you always use CreateNewProc().
When you use one of the two mentioned functions, your subtask or process
will exit reliably - if they don't, you probably have a bug in your code.
You should not exit the main process as long as one of your subprocesses
or tasks are running (obviously...).
You may only remove subtasks (or processes?) as long as it is not
calling any amiga-library-function (because these might be sending messages,
waiting for signals, using other stacks, etcetera).
There is no Wait() function with which you can wait for a process or task
to complete.

>>
>> Next question: I am using a process because I am writing a NNTP news reader
>> program, and I want the sub-process to do the communication across the 'net
>> (using AmiTCP).  It's not clear to me that a task would be sufficient to do
>> this.  Would it be?
>>
>
>Again NO!!! Tasks are very limited in their capabilities, they can't use DOS services i believe, but
>if you're not using any i guess a task would suffice.
>

## That is true, tasks can not use in any way the dos.library, nor can they
call any amiga-library-function that might call dos.library (e.g. OpenDiskFont).
Therefor, I suggest you to create a process always, using CreateNewProc().


--
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Jaco Barnhoorn               [e-mail]
Software Test Engineer       [e-mail]
Alcatel Telecom Systems
Rijswijk, The Netherlands
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