Ending a Process?

[Kelsey]

After I use fork to begin running a process, how do I end it?

[MihaiG]

possibly

code:

end fork

???

[Cervantes]

ELCOMANDANTE wrote:

possibly

code:

end fork

???

Nope. Use return and a flag variable.

AsianSensation wrote:

Yeah, I should have said it earlier, guess I forgot, sorry.

but things like this:

code:

var flag : boolean := false process doSomething     if flag = true then         return     end if     put "Hello" end doSomething for rep : 1 .. 100     put "Hi"     fork doSomething     if rep > 20 then         flag := true     end if end for

return will terminates the process.

[Martin]

Don't use processes.

[Kelsey]

martin wrote:

Don't use processes.

Then how would you suggest I run a timer in my program?


And to the other two of you, thnaks!

[Cervantes]

Kelsey wrote:

martin wrote:

Don't use processes.

Then how would you suggest I run a timer in my program?

You could put it in your main loop. What do you mean when you say a "timer", however? A timer since the program has started (or since some event occured)? Time.Elapsed, inside your main loop, will work fine.

[Kelsey]

Cervantes wrote:

You could put it in your main loop. What do you mean when you say a "timer", however? A timer since the program has started (or since some event occured)? Time.Elapsed, inside your main loop, will work fine.

It starts when an even occurs. How do I encorperate Time.Elapsed so it can be outputed in the run window?

[Cervantes]

huh?

code:

put Time.Elapsed

Or, a little more complex:

code:

for i : 1 .. 100     delay (10)     locate (1, 1)     put "Current Time: ", Time.Elapsed end for var event_occured_at := Time.Elapsed locate (2, 1) put "Event \"for loop complete\" occured at ", event_occured_at loop     locate (3, 1)     put "Time Since event occured : ", Time.Elapsed - event_occured_at end loop

[Martin]

Well, you have your main loop keep track of the time that has elapsed since the beginning of the program.

Each event is then tied to a start time, and has a life, and this is all checked in the main loop. It's much cleaner.

In pseudocode:

code:

while (not gameOver())     totalTime = Time.Elapsed - startTime     checkEventsForTimeBasedConditions()     .... end while

[Kelsey]

Cervantes wrote:

huh?

code:

put Time.Elapsed

Or, a little more complex:

code:

for i : 1 .. 100     delay (10)     locate (1, 1)     put "Current Time: ", Time.Elapsed end for var event_occured_at := Time.Elapsed locate (2, 1) put "Event \"for loop complete\" occured at ", event_occured_at loop     locate (3, 1)     put "Time Since event occured : ", Time.Elapsed - event_occured_at end loop

This doesn't really seem like what I'm trying to do, but thanks for explaining that. Why is it so bad to use processes anyways?

[Martin]

Processes behave somewhat inconsistantly and unpredictably, and are often used inefficiently.

The basic idea of writing a program is to perform as few calculations as necissary, and when people use processes, 99% of the time, they are calculating something over and over, and only using that calculation a couple of times.

[Kelsey]

martin wrote:

Processes behave somewhat inconsistantly and unpredictably, and are often used inefficiently.

The basic idea of writing a program is to perform as few calculations as necissary, and when people use processes, 99% of the time, they are calculating something over and over, and only using that calculation a couple of times.

code:

process timer %Timer for the game, runs parallel later when game is begun     loop         time_count := time_count + 1         time_count2 := intstr (time_count)         delay (1000)         drawfillbox (140, 240, 180, 260, 7)         Font.Draw (time_count2, 145, 245, font, brightred)         exit when time_count = 999     end loop end timer . . . %Bunch of other stuff here . . . loop         Mouse.Where (x, y, b)         if b = 1 and x < 120 and x > 80 and y < 275 and y > 235 then             fork timer             drawfillbox (80, 235, 120, 275, 25)             Font.Draw ("STOP", 83, 250, font, black) . . . Bunch more stuff . . . end loop

Basically, when you click the button to start the game (Minesweeper), the timer needs to begin. What I wanted to do was end the process when the button is clicked again (it changes to a stop button once the game begins).

I have a lot of conditions that need to be checked continuosly throughout the loop, so adding a delay in there for my time to show up every second wouldn't be so great. I think using a process here works .

[Cervantes]

Kelsey wrote:

I have a lot of conditions that need to be checked continuosly throughout the loop, so adding a delay in there for my time to show up every second wouldn't be so great. I think using a process here works.

Nah:

code:

var elapsedSeconds := 0 loop     %do stuff     %do drawing stuff     if Time.Elapsed >= elapsedSeconds * 1000 then         elapsedSeconds += 1         locate (1, 1)         put elapsedSeconds     end if     %have your View.Update and delay here end loop

[Kelsey]

Thank-you!