Parallel Program Editor

John Reese, CS 139c Project 1997

The goal of this project is to build a graphical editor for parallel programs. The editor will make it possible to lay out process topologies and edit process code from a graphical, heads up topological view, which in many cases is a more natural and higher level way of approaching concurrent programs. It will produce code for mcc, a parallelized version of C developed at Caltech by Marcel van der Goot.

Implementation

The project will be implemented using the Perl/Tk toolkit.

Proposal

My original project proposal, converted to HTML.

Timeline

4/8/97: create a Perl/Tk based framework on which to build the editor.
4/11/97: create a prototype of the icons representing processes and develop code in the framework to manipulate them (i.e. to move them and so on).
4/15/97: add code to parse mcc files and generate the process icons from the function prototypes.
4/18/97: add ability to edit code and update process icons based on results. Ideally, it should be possible to do this asynchronously (i.e., keep editing in the tool while the text editor is open).
4/25/97: add interface.
4/28/97: create a prototype of the lines representing channels connecting processes, and code in the framework to support them (drawing, matching port types, redrawing as icons are moved).
5/5/97: add code to create a process skeleton builder from the channel layout.
5/12/97: add code to output a makefile.
5/19/97: create code to manipulate process interfaces graphically (changing number, names of channels).
6/2/97: work out a scheme for concealing more complex topologies behind process-like icons (hierarchy).

Implementation Journal

4/15/97 - Mcc code for a process, and corresponding process icon:

process Pal(in {char} p, out {char} q,
            out {int} answ, in {int} bnsw) {
    int w;
    char x, y;

    p?y;
    w= 1;
    answ!w;

    while (1) {
        p?x;
        answ!(w && (x == y));
        q!x;
        bnsw?w;
    }
}

4/25/97 - A screen shot of the interface. The cursor is in "PalCap", which is why it's blue. Its prototype is displayed in the little text box at the bottom. The file corresponding to process "Pal" is currently being edited, which is why its colored red. When a process is being edited, it won't allow certain operations (like running another editor on it). The pane on the right is a list of all the available process icons. Icons pulled from this list are arranged in the larger pane to the left and connected with channels, which I haven't implemented yet.

05/13/97 - Two processes connected by channels (the channels are drawn with Bezier curves of some kind) and the corresponding Spawn process and Makefile as generated by the program.

Topology


void Spawn(void) {
        channel c[4]

        Pal(c[2], c[3], c[1], c[0]);
        Pal(c[3], c[2], c[0], c[1]);
}



# Automatically generated Makefile

MCC=mcc
MCCFLAGS=

out: main.o procs/palin/pal.o spawn.o
        ${MCC} ${MCCFLAGS} main.o procs/palin/pal.o spawn.o -o out

main.o:
procs/palin/pal.o:
spawn.o:

clean:
        -rm -f *.o

.SUFFIXES: .m .o

.m.o:
        ${MCC} ${MCCFLAGS} -c $^ $@

06/01/97 - About time. Got redraw after an editor window closes to work. Recolors all the channels as appropriate, moves them around if the location of their start and end ports changed, and deletes them if they're no longer legal connections (in changes to out, one of the types changed, etc.).

06/13/97 - Got it to work with real programs. It was segfaulting at first, because my spawn code was wrong. I forgot to call newchan on all of the channels. It now compiles and runs both the constant response time stack and constant response time palindrome recognizer from first term. Didn't get hierarchical processes to work, nor did I get it to load a spawn file and redraw the topology window therefrom. Example working program (this is the crt stack):

CRT Stack

# Make
mcc  -c main.m -o main.o
mcc  -c spawn.m -o spawn.o
mcc  ./procs/stack/buffy.o main.o ./procs/stack/hofstee.o
./procs/stack/hoffcap.o spawn.o ./procs/stack/hoffeed.o -o out


# Run
./out
popped: in

popped: this

popped: order

Program terminated with 5 process(es) left.

Source code

Tarball of the final project

author