[M3devel] Thread testing program

[Mika Nystrom]

Hmm, to make that program really useful it needs two enhancements:

1. check that the threads are indeed created (on AMD64_LINUX, the
system deadlocks for me after 50)

2. check that the running threads are, indeed, making some sort of
progress...

As it is it is useful in a debugger but not for any kind of automated
or foolproof testing, yet.

     Mika


Mika Nystrom writes:
>
>Hello everyone,
>
>After studying failure modes and implementation of the current
>threading implementation in CM3, I've developed a little stress-testing
>program, attached.  Currently it crashes in various ways.
>
>It takes one command-line argument, the approximate number of threads
>to create (e.g., 100).  It creates threads of three types:
>reader (reads a file), forker (forks a process), allocator (allocates
>memory that constantly goes out of scope).
>
>Files attached below.  Happy 1/11/11.
>
>    Mika
>
>My m3makefile:
>
>import ("libm3")
>
>implementation ("Main")
>
>program ("threadtest")
>
>My m3overrides (optional):
>
> if defined("CM3_VERSION")
>        /* Critical Mass Modula-3 */
>% see http://www.elegosoft.com/cm3/doc/help/cm3/cm3.html
>
>% not sure about this:
>      build_standalone()
>
>      m3_optimize("")
>end
>
>My Main.m3:
>
>
>(* $Id: Main.m3,v 1.1 2011/01/11 10:06:21 mika Exp $ *)
>
>MODULE Main;
>
>(* threading stress-test *)
>
>IMPORT Params, Scan, Thread, Rd, FileRd, Wr, FileWr, Process;
>
>VAR n := Scan.Int(Params.Get(1));
>
>PROCEDURE MakeReaderThread() =
>  BEGIN 
>    EVAL Thread.Fork(NEW(Thread.Closure, apply := RApply)) 
>  END MakeReaderThread;
>
>PROCEDURE MakeForkerThread() =
>  BEGIN 
>    EVAL Thread.Fork(NEW(Thread.Closure, apply := FApply)) 
>  END MakeForkerThread;
>
>PROCEDURE MakeAllocatorThread() =
>  BEGIN 
>    EVAL Thread.Fork(NEW(Thread.Closure, apply := AApply)) 
>  END MakeAllocatorThread;
>
>(**********************************************************************)
>
>PROCEDURE RApply(cl : Thread.Closure) : REFANY =
>  BEGIN
>    LOOP
>      WITH rd = FileRd.Open(Filename) DO
>        TRY
>          LOOP
>            VAR c := Rd.GetChar(rd); BEGIN END
>          END
>        EXCEPT
>          Rd.EndOfFile => Rd.Close(rd)
>        END
>      END
>    END
>  END RApply;
>
>PROCEDURE FApply(cl : Thread.Closure) : REFANY =
>  BEGIN
>    LOOP
>      WITH proc = Process.Create("sleep",
>                                 ARRAY OF TEXT { "1" }) DO
>        EVAL Process.Wait(proc)
>      END
>    END
>  END FApply;
>
>PROCEDURE AApply(cl : Thread.Closure) : REFANY = 
>  BEGIN
>    LOOP
>      VAR
>        arr := NEW(REF ARRAY OF INTEGER, 1025);
>      BEGIN
>        FOR i := FIRST(arr^)+1 TO LAST(arr^) DO
>          arr[i] := arr[i] - arr[i-1]
>        END
>      END
>    END
>  END AApply;
>
>
>CONST Filename = "hohum";
>
>PROCEDURE WriteAFile() =
>  BEGIN
>    WITH wr = FileWr.Open(Filename) DO
>      FOR i := 1 TO 256 DO
>        FOR j := 1 TO i DO
>          Wr.PutChar(wr, VAL(ORD('A') + i MOD 25, CHAR))
>        END;
>        Wr.PutChar(wr, '\n')
>      END
>    END
>  END WriteAFile;
>
>BEGIN
>  WriteAFile();
>  FOR i := 1 TO n DIV 3 DO
>    MakeReaderThread()
>  END;
>  FOR i := 1 TO n DIV 3 DO
>    MakeForkerThread()
>  END;
>  FOR i := 1 TO n DIV 3 DO
>    MakeAllocatorThread()
>  END;
>
>  LOOP
>    Thread.Pause(1.0d0)
>  END
>END Main.
>