<div dir="ltr">For reference, I was on IRC with Jack when he first ran into this, and reproduced the jittery behavior on my own machine with a freshly started DrRacket. The first time I ran the program, and perhaps every 10th time I ran it, it would hiccup briefly within a second of hitting run, then run smoothly. This is on a relatively recent Mac Mini with 16 GB RAM, 4 physical / 8 virtual cores, and little else running at the time.<br> <div class="gmail_extra"><br clear="all"><div>Carl Eastlund</div> <br><div class="gmail_quote">On Wed, Aug 7, 2013 at 5:22 PM, Robby Findler <span dir="ltr"><<a href="mailto:robby@eecs.northwestern.edu" target="_blank">robby@eecs.northwestern.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div dir="ltr">I just tried this on my mac (a fairly recent machine but not a super-duper powerhouse) and it didn't seem jittery. <div><br></div><div>What happens if you save it in "file.rkt" and, from a terminal window, run "racket file.rkt"? Here's the precise command I ran (on a mac):</div> <div><br></div><div> /Applications/Racket\ v5.3.5/bin/racket -W debug@GC ~/file.rkt<br></div><div><br></div><div>I didn't see too many GCs once the game started and the ones I saw were unlikely to be noticeable (they were 3-5 msec; well below the 16 msec screen refresh rate).<br> </div><div><br></div><div>If that makes a difference on your machine, perhaps that means it is time to restart DrRacket (as GCs can take significantly longer for programs running inside DrRacket, esp. if there is a leak somewhere).</div> <span class="HOEnZb"><font color="#888888"> <div><br></div><div>Robby</div></font></span></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Aug 7, 2013 at 2:58 AM, Robby Findler <span dir="ltr"><<a href="mailto:robby@eecs.northwestern.edu" target="_blank">robby@eecs.northwestern.edu</a>></span> wrote:<br> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Well, allocation is what triggers GC and there appears to be a fair amount of that in your program. I am not in a good position to run your code and nothing jumps out at me from a first glance at the gist but probably it is allocation that originates there (not that that<div> means your code is necc. buggy).</div><div><br></div><div>Fundamentally, functional image construction (and lists) requires allocation and allocation requires GC. That said there is probably something's we can fix here. I will try to take a closer look in the coming days of no one beats me to it. <span><font color="#888888"><span></span></font></span></div> <span><font color="#888888"> <div><br></div></font></span><div><span><font color="#888888">Robby</font></span><div><div><span></span><br><br>On Wednesday, August 7, 2013, Jack Firth wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div dir="ltr">Hey users, I'm experimenting with some simple games using big-bang from 2htdp/universe and I keep running into stuttering problems. It seems to be the garbage collector slowing things down (green recycle symbol in drracket is on whenever the program is frozen).<div> <br></div><div>Increasing the memory limit or removing the limit altogether doesn't seem to affect the problem, and I've checked in the IRC and it occurs on other machines as well, all of which have the specs that it shouldn't have any problems with slowdown. Are there issues with big-bang and it's event handling?</div> <div><br></div><div>Source - <a href="https://gist.github.com/Universalist235/6171371" target="_blank">https://gist.github.com/Universalist235/6171371</a></div></div> </blockquote></div></div></div> </blockquote></div><br></div> </div></div><br>____________________<br> Racket Users list:<br> <a href="http://lists.racket-lang.org/users" target="_blank">http://lists.racket-lang.org/users</a><br> <br></blockquote></div><br></div></div>