- GftThreads

From: Douglas G. Danforth <"Douglas>
Date: Mon, 25 Apr 2005 13:53:12 -0400

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Folks,
I have implemented a module GftThreads that works for simple tasks and
operates in nanosecond response times (16ns on my machine).
The simple interface (patterned a little after Services.Action) looks like.

DEFINITION GftThreads;

   TYPE
     Action = POINTER TO ABSTRACT RECORD
       (a: Action) Do, NEW, ABSTRACT;
       (a: Action) Start, NEW;
       (a: Action) Stop, NEW
     END;

END GftThreads.

Calling action.Start puts the function action.Do into a tight loop
running in a child thread. Calling action.Stop from the parent
terminates this loop and the thread. The child shares the memory space
of the parent.

However, I am getting in over my head. The functions that the user
places in action.Do must be 'thread-safe'. Neither Out.String, nor
XYplane.Dot seem to satisfy the 'thread-safe' condition. They both work
  for a single Start-Stop pair but a second Start causes the system to
hang (for Out there seems to be an interaction with the routines that
write to the log and preconditions are violated).

I would like the user not have to worry about 'thread-safety' and so
believe something like critical regions are necessary.

Does anyone have experience with Windows' threads that could give some
pointers?

-Doug

--- BlackBox
--- send subject HELP or UNSUBSCRIBE to blackbox{([at]})nowhere.xy



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Received on Mon Apr 25 2005 - 19:53:12 UTC