Re: [racket-users] trying to use futures for some calculations

2020-06-17 Thread Dominik Pantůček
Hi Alex, I finally got to investigate the issue in depth. And there are two major problems blocking your implementation from running the futures in parallel. 1) Allocations of boxed flonums. I tried to get rid of those by allocating "scratchpad" flvectors and mapping everything onto them. The

[racket-users] New package: mind-map

2020-06-17 Thread Sage Gerard
I take notes using short indented lines, so I wrote a #lang using Pythonic indentation rules to interpret my notes as nodes in a mind map. Source for the interested: https://github.com/zyrolasting/mind-map With thanks to Hadi Moshayedi for racket-graphviz. I use that to render the maps. Time

Re: [racket-users] trying to use futures for some calculations

2020-06-17 Thread Sam Tobin-Hochstadt
I tried this out, by adding 1.0 as the third argument in `in-range` in all cases. The performance in Racket BC increased, but there's still no parallelism. In Racket CS, it appears to have made things slower, so I need to investigate more. Sam On Wed, Jun 17, 2020 at 10:36 AM Matthew Flatt

RE: [racket-users] Re: trying to use futures for some calculations

2020-06-17 Thread Jos Koot
In addition, some time ago I did use futures which did parallelization very well when using distinct parts of the same vector. I did not need unsafe for that. Jos -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group

RE: [racket-users] Re: trying to use futures for some calculations

2020-06-17 Thread Jos Koot
It’s long ago, but I worked nicely with parallelization on a CDC 205 both in assembler and Fortran (CDC has expired shortly after). IIRC it did not protect against simultaneous updating the same memory location. But what I do recall is that it is very important that parallel processes use

Re: [racket-users] Why does this counter behave differently in different runtimes?

2020-06-17 Thread Neil Van Dyke
Compiler bugs have been so blessedly rare in Racket, maybe there should be a page on the Web, honoring those who found a compiler bug? I would nominate Sage and Alexis for this one. And Matthew, though we'd have to make sure he's not mis-incentivized by the glory of bug-finding, to start

Re: [racket-users] Why does this counter behave differently in different runtimes?

2020-06-17 Thread Sage Gerard
Thank you all so much! I'm glad it wasn't a huge mystery in the end. Original Message On Jun 17, 2020, 9:13 AM, Matthew Flatt wrote: > Yes, clearly a BC compiler bug --- and probably almost as old as > Racket. The bug was specific to `set!` on a locally bound variable as > the

Re: [racket-users] Re: trying to use futures for some calculations

2020-06-17 Thread Dominik Pantůček
I've looked at it only briefly (it's the end of the semester and grading is due soon). > > > I would *love* to be proven wrong on this, but I think it's rare to > be able to get decent parallelization in practice using futures. You > may have better results using places, but it will

Re: [racket-users] Re: trying to use futures for some calculations

2020-06-17 Thread Robby Findler
On Wed, Jun 17, 2020 at 8:56 AM Brian Adkins wrote: > On Wednesday, June 17, 2020 at 4:50:44 AM UTC-4, Alex Harsanyi wrote: >> >> >> I am trying to speed up an algorithm using futures, but I am getting some >> unexpected results (and no real speed improvements), and I was wondering if >> someone

Re: [racket-users] trying to use futures for some calculations

2020-06-17 Thread Matthew Flatt
At Wed, 17 Jun 2020 10:24:37 -0400, Sam Tobin-Hochstadt wrote: > - on Racket BC, operations like `+` do indeed block ... which mixing, say, fixnum and flonum arguments, but not when operating on all fixnums or all flonums. In this case, it may be the `in-range` with flonum bounds that results in

Re: [racket-users] trying to use futures for some calculations

2020-06-17 Thread Sam Tobin-Hochstadt
I have not yet done much investigating on this, but: - on Racket BC, operations like `+` do indeed block, and effectively you need to replace them with lower-level operations that don't (such as `unsafe-fl+`). Typed Racket can help with this, or you can do it all by hand. As you note, that makes

[racket-users] Re: trying to use futures for some calculations

2020-06-17 Thread Brian Adkins
On Wednesday, June 17, 2020 at 4:50:44 AM UTC-4, Alex Harsanyi wrote: > > > I am trying to speed up an algorithm using futures, but I am getting some > unexpected results (and no real speed improvements), and I was wondering if > someone more experienced could have a look a the code and tell me

[racket-users] Re: trying to use futures for some calculations

2020-06-17 Thread Brian Adkins
On Wednesday, June 17, 2020 at 4:50:44 AM UTC-4, Alex Harsanyi wrote: > > > I am trying to speed up an algorithm using futures, but I am getting some > unexpected results (and no real speed improvements), and I was wondering if > someone more experienced could have a look a the code and tell me

Re: [racket-users] Why does this counter behave differently in different runtimes?

2020-06-17 Thread Matthew Flatt
Yes, clearly a BC compiler bug --- and probably almost as old as Racket. The bug was specific to `set!` on a locally bound variable as the first subexpression of `begin0`. I've pushed a repair. Thanks! At Wed, 17 Jun 2020 03:35:51 -0500, Alexis King wrote: > This is quite curious. It appears to

Re: [racket-users] Why does this counter behave differently in different runtimes?

2020-06-17 Thread George Neuner
Sorry for the noise:  it behaves as you say returning "!", "2", ...    Somehow I paths screwed up and was running CS when I thought I was running regular (bytecode) Racket. Sigh! George -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To

[racket-users] scribble: how to put a bar above text?

2020-06-17 Thread Jos Koot
Thanks to all of you for your help. I have tried some of your suggestions. They are promising. Meanwhile I have found out that I can do the following: - Create an equation in Word - Save it as a picture - Convert it to gif - Insert it with @image Nevertheless I’ll look further into your

Re: [racket-users] Why does this counter behave differently in different runtimes?

2020-06-17 Thread George Neuner
It seems to work ... i.e. returns # ... in Windows.  I tried it in 7.6 and 7.7,  both 32 and 64 bit versions.   Not near my Linux machine to try it there. The expansion in all cases is the same and seems reasonable: (module count racket   (#%module-begin    (module

[racket-users] trying to use futures for some calculations

2020-06-17 Thread Alex Harsanyi
I am trying to speed up an algorithm using futures, but I am getting some unexpected results (and no real speed improvements), and I was wondering if someone more experienced could have a look a the code and tell me what am I doing wrong. I put up the code in this repository:

Re: [racket-users] Why does this counter behave differently in different runtimes?

2020-06-17 Thread Alexis King
This is quite curious. It appears to be a compiler bug. Here’s a very slightly smaller test case: #lang racket/base (define count! (let ([i 0]) (λ () (begin0 (set! i (add1 i)) (+ i) (count!) The fully-expanded program looks fine, so