Poly/ML June 2011

polyml@lists.polyml.org

5 participants
9 discussions

Inspecting structures
by ramana.kumar＠gmail.com 27 Jan '16

27 Jan '16

Is there a way to look at the contents (i.e. signature) of a structure without opening it? (I suppose you could just open it then call a lot of PolyML.Compiler.forgetXXX, but that's quite tedious) Also, is it possible to retrieve the long path of an identifier in scope? Something that will, for example, take the rev in scope and say that it came from List. Finally, what about searching for an identifier that would come into scope if you opened some structures?

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[Fwd: Re: [polyml] Building Poly/ML on MacOS X 10.6]
by rda＠lemma-one.com 29 Dec '14

29 Dec '14

I wrote: > I am completely baffled. I thought I hada solved all my problems on > MacOS X > 10.6 and was just tidying up, when I had to recompile a 32 bit > version of > Poly/ML to test a tidied up make file. This failed because > PolyML.Compiler.printTypesWithStructureName no longer exists. The same > problem happened when i rebuild a 64 bit version. What has happened? but it was a false alarm: my make file was wrong for other reasons and the absence of PolyML.Compiler.printTypesWithStructureName was not relevant. No doubt there are good reasons why this variable has been withdrawn. Regards, Rob.

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Repeated ascriptions
by aleks0＠gmail.com 28 Jun '11

28 Jun '11

Why are repeated signature ascriptions slow? Suppose Foo is a pretty big structure, which has already been ascribed the signature FOO: > structure X = Foo; (* fast, note that poly already knows Foo, and thus X, is a FOO *) structure X : FOO > structure X = Foo : FOO (* slow *) structure X : FOO > structure X : FOO = Foo (* slow *) structure X : FOO Poly already knows that Foo is a FOO, so surely this should return instantly, but it acts like its typechecking the whole struct again. While it's not necessary to do the ascriptions above (poly is smart enough to figure out X is a FOO, even in the first case), this same issue seems to be seriously slowing down functor evaluation, where you can't avoid ascription. I thought using opaque ascription might skirt the issue, but the same thing happens. Is poly just being silly, or this this a consequence of how the type system works? a

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Nice parallelisation examples in poly/ML
by aleks0＠gmail.com 23 Jun '11

23 Jun '11

Hello polyglots, I was wondering, do any of you have some little examples or chunks of code that do some parallel computation, possibly using some of the code in Isabelle's "Pure/Concurrent" dir? Say, for instance, I have a stack of names and an (expensive) function from names to bools. I'd like to spawn a handful of workers and wait for them to finish. The workers then pop names off, compute the boolean function and push the names back on to "true" and "false" stacks. This kind of setup should be pretty straightforward to implement, but a few pointers as far as what structs to use and how to use them would be useful. Thanks! Aleks

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IEEE reals
by David.Matthews＠prolingua.co.uk 17 Jun '11

17 Jun '11

I've fixed a bug that Grant Passmore reported where the IEEEReal.setRoundingMode settings weren't working on X86. I've written a small regression test for this particular case but it would be nice to test Poly/ML's real numbers more completely. I'm not that familiar with real number arithmetic and even less so with the rather arcane areas of IEEE reals. Is there anyone who could provide some more tests for this part of Poly/ML? It may be that there are some tests available in another language that could be adapted, perhaps as a student project. David

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Thread Status Flags
by dathayer＠microsoft.com 10 Jun '11

10 Jun '11

Dave, I do have one more question. You stated that >Poly/ML currently uses a single word for these. The mapping is >1 -> Broadcast >OR-ed with: >2 -> Synch >4 -> Asynch >6 -> AsynchOnce Where is the InterruptDefer flag status stored? David

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Semantics of Threading Intrrupt Flags and proper interpretation in .Net simulation
by dathayer＠microsoft.com 10 Jun '11

10 Jun '11

Dave, Thank you I believe I have the necessary information now to generate a workable simulation of your Thread.SML in F#. David Date: Tue, 07 Jun 2011 17:55:11 +0100 From: David Matthews <David.Matthews(a)prolingua.co.uk> To: polyml(a)inf.ed.ac.uk Subject: Re: [polyml] Semantics of Threading Intrrupt Flags and proper interpretation in .Net simulation Message-ID: <4DEE57EF.30709(a)prolingua.co.uk> In-Reply-To: <717F714B587F944C88837A99AA4D0081404C275E(a)TK5EX14MBXC116.redmond.corp.microsoft.com> References: <717F714B587F944C88837A99AA4D0081404C275E(a)TK5EX14MBXC116.redmond.corp.microsoft.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: list Message: 3 Hi David, On 06/06/2011 23:48, Dave Thayer wrote: > My questions are > > 1. What is the semantics of these flags as related to the behavior of threads and the Interrupt signal? Have you looked at http://www.polyml.org/docs/Threads.html ? There's an explanation there. If it's not clear please let me know. This is really one of the most problematic bits of the threading model in Poly/ML. > > 2. Can a single word be used to model these flags thusly (see below) given that I am using a completely different runtime than what you are calling into? > 1 -> InterruptDefer > 2 -> InterruptSynch > 4 -> InterruptAsynch > 6 -> InterruptAsynchOnce > 8 -> BroadcastInterrupt Poly/ML currently uses a single word for these. The mapping is 1 -> Broadcast OR-ed with: 2 -> Synch 4 -> Asynch 6 -> AsynchOnce It's actually in the second word of a 4-word thread object. The first word is a tagged integer which is an index into the thread table in the run-time system, the third points to a list of thread-local data and the fourth is a "hint" used in interrupt handling. Regards, David ------------------------------ _______________________________________________ polyml mailing list polyml(a)inf.ed.ac.uk http://lists.inf.ed.ac.uk/mailman/listinfo/polyml End of polyml Digest, Vol 69, Issue 2 ************************************* -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.

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Semantics of Threading Intrrupt Flags and proper interpretation in .Net simulation
by dathayer＠microsoft.com 07 Jun '11

07 Jun '11

Dave Matthews, I am building a thread manager for the .NET CLR that emulates your threading model in Poly ML I am a little confused by a couple of issues in your file Basis/Thread.Sml You have a set of associated types declared as such datatype threadAttribute = EnableBroadcastInterrupt of bool | InterruptState of interruptState and interruptState = InterruptDefer | InterruptSynch | InterruptAsynch | InterruptAsynchOnce You then create functions for writing these into a tuple of words as bit flags With the following mapping 1 -> InterruptDefer 2 -> InterruptSynch 4 -> InterruptAsynch 6 -> InterruptAsynchOnce And then mapping the lowest bit of the other word in the tuple to the flag in EnableBroadcastInterrupt My questions are 1. What is the semantics of these flags as related to the behavior of threads and the Interrupt signal? 2. Can a single word be used to model these flags thusly (see below) given that I am using a completely different runtime than what you are calling into? 1 -> InterruptDefer 2 -> InterruptSynch 4 -> InterruptAsynch 6 -> InterruptAsynchOnce 8 -> BroadcastInterrupt I now you don't get many questions from people working with the CLR so I appreciate your patience David Thayer

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Memory leak? Poly/ML SVN 1307
by aleks0＠gmail.com 07 Jun '11

07 Jun '11

I've just updated to the latest SVN of poly, and my compile times have ballooned up. Prodding it a bit, it looks to me like there's a memory leak in the interpreter. Here's what I do to get it to happen: 1. Fire up poly and load a modest heap (59 megs) containing about 100 structures and functors. top shows poly's RAM usage goes to a little over 59 megs. 2. Run some pretty functor-heavy code, including some code that looks (essentially) like this: structure Structure1 = Functor1(....); structure Structure2 = Functor2(structure Foo = Structure1); structure Structure3 = struct open Structure1; Structure2; end structure Structure4 = Structure3 : SIG Admittedly, these are some pretty big structs, and poly's RAM usage hits over a gig, and doesn't go back down once execution is finished. "PolyML.fullGC ();" seems to have no effect. 3. Save the heap, still < 70 megs. 4. Close and open poly w new heap, RAM usage still < 70 megs So, the compile-time slowness seems to be poly filling the system's RAM and starts swapping pages. I included the code above on the off chance there's some cyclic dependency between the structs that keeps some junk from being garbage collected. I can give SVN links if you want to see the offending code itself, but its part of a pretty large project, so I don't know how helpful that would be. Thanks! Aleks

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Poly/ML June 2011