I found this answer helpful. I have one follow-up question: You said
that you use MoMLParser.parse(String) to open multiple instances. Does
using teh MoMLParser.parse(URL) version of that method NOT open multiple
instances?
Brian Hudson wrote:
Do I remember correctly that Ptolemy does not in any way support
Java concurrency or multi-threading?
This depends on your domain really. PN for example uses quite a bit of
threading.
If so, then I would assume that one couldn't safely run 2 models
in one JVM, even if each had its own instances of
TypedCompositeActor, Manager, Director, etc. If one wanted
concurrency, one would run separate JVM's, each with one model
that would have no contact with any other model. Right?
You can safely run multiple models in one JVM. You just need to make
sure that you have two instances of the model in memory. We do this by
using the MoMLParser.parser(String) to open multiple instances of the
same model.
If (in one JVM) I had a program running that wanted to run several
models (similar to each other), one after the other, how much
reuse of Ptolemy instances makes sense? Would you recommend
nulling all references after each model run, and instantiating all
Ptolemy objects fresh? Or would it make any sense to reuse the
same TypedCompositeActor, Manager, Director, etc?
We do this as well. We have some code that "injects" some actors into
a model before me run it, and we modify several parameters. When the
execution has completed we remove these "injected" actors and reset
the parameters. When running sequential runs on the same model we
reuse everything.
Does Ptolemy have a way to scrub all actors out of a model,
allowing the creation of new ones?
We create all of our "injected" actors in their own composite at the
top level. That we when we want to delete them we can simply delete
that one CompositeEntity.
Brian
On Fri, Jul 25, 2008 at 12:27 PM, Richard Ware <[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>> wrote:
1) Do I remember correctly that Ptolemy does not in any way support
Java concurrency or multi-threading? If so, then I would assume
that one
couldn't safely run 2 models in one JVM, even if each had its own
instances of TypedCompositeActor, Manager, Director, etc. If one
wanted concurrency, one would run separate JVM's, each with one
model that would have no contact with any other model. Right?
2) If (in one JVM) I had a program running that wanted to run
several models (similar to each other), one after the other, how
much reuse
of Ptolemy instances makes sense? Would you recommend nulling
all references after each model run, and instantiating all Ptolemy
objects
fresh? Or would it make any sense to reuse the same
TypedCompositeActor, Manager, Director, etc? Regardless of
which approach I use, I plan to delete all actors from the first
model run
and create all actors for the second run fresh, for reasons
involving the
nature of my simulation. Does Ptolemy have a way to scrub all actors
out of a model, allowing the creation of new ones?
I look forward to your clarifications.
Richard Ware
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