Thread: 1, 2, 3, 4 take the elevator

an interesting problem to try and model:

a 20 storey building with two elevators, each can move independantly and at the same time in different directions, all features must be present (doors open close etc) and each elevator must be able to be called or sent to different floor at the same time.

i tried to solve this while bored one day and after several weeks i gave up , i dont think real time systems prgramming is for me.
have a try

hmm.....think i could do it...

supposed to do it graphically i am guessing?

yeah you just have booleans saying whether each elevator is moving, then call the movement functions...you also gotta have a couple vars to keep track of their floor numbers

I am guessing they are in different elevator shafts also, b/c you dont want them to crash against each other...

seems possible..

well i had this problem is my ASM(TASM) class....... It is quite easy.....

>>> each can move independantly and at the same time in different directions,

Semantics I'm sure, but to me, that implies that an individual elevator can be moving up and down at the same time. That adds some interest to the model.

This problem is used in Deitel's C++ book, primarily as an example of UML modeling but it walks through all the code.

you dont even need multithreading for this, so why even mention it.

it is pretty simple:

Code:

bool elevator1switch;
bool elevator2switch;
int floorcur1, floorcur2, floor1, floor2;

while(1)
{
MoveElevator ( Elevator1, floorcur1, floor1, elevator1switch );
MoveElevator ( Elevator2, floorcur2, floor2, elevator2switch );

switch ( command )
{
    case whatever:
          floor1 = whatever;
          floor2 = whatever;
          break;
}

}

Originally posted by DavidP
you dont even need multithreading for this, so why even mention it.

it is pretty simple:

Code:

bool elevator1switch;
bool elevator2switch;
int floorcur1, floorcur2, floor1, floor2;

while(1)
{
MoveElevator ( Elevator1, floorcur1, floor1, elevator1switch );
MoveElevator ( Elevator2, floorcur2, floor2, elevator2switch );

switch ( command )
{
    case whatever:
          floor1 = whatever;
          floor2 = whatever;
          break;
}

}

Without multithreading, how can they be moving at the same time? In your model, the first one would move, then the second, then the first, then the second...etc.

umm...put each elevator into its own thread, and do it that way...

I take it you lot dont design elevators(now reffered to as lifts). Lots of lifts at UNI. Just concerned thats all. Heh...

Oh yes there are lots of lifts, each independant......help me here, this is soooooooooo boring.