Re: [Chicken-users] Best way to share memory between C and Chicken
Nevertheless: maybe it would be feasible to do all second gen gc in a dedicated thread and force a minor gc before passing data between threads? Would it? Unfortunately, execution and garbage collection are tightly interleaved in the cheney-on-the-mta model. But the idea is intriguing. Implementing it would be the usual hell, of course. Yet it sounds like something one should think about. Very interesting. cheers, felix ___ Chicken-users mailing list Chicken-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] Best way to share memory between C and Chicken
Felix scripsit: Unfortunately, execution and garbage collection are tightly interleaved in the cheney-on-the-mta model. Minor collection is, but major collection could be run in a separate thread so that it can run concurrently (even on a second core) with the rest of the program. As it happens, I was reading about a concurrent GC just the other day which sounded interesting -- and just happens to be named Chicken, how cool is that? http://www.cs.technion.ac.il/~erez/Papers/real-time-pldi.pdf -- John Cowan http://ccil.org/~cowanco...@ccil.org We want more school houses and less jails; more books and less arsenals; more learning and less vice; more constant work and less crime; more leisure and less greed; more justice and less revenge; in fact, more of the opportunities to cultivate our better natures. --Samuel Gompers ___ Chicken-users mailing list Chicken-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] Best way to share memory between C and Chicken
*cringe* This will certainly expose what is and is not thread-safe within Chicken. I've worked with a /team/ in implementing such behaviour in the Unreal engine, albeit a frankenengine of sorts, and with three dedicated programmers the endeavour required about a month. But we had the benefit of knowing the totality of the code's usage, whereas implementing such behaviour could break all sorts of applications written for Chicken Scheme. OTOH, this would be an enormous boon to the flexibility of Chicken Scheme. If it were possible to safely run GC on separate threads, or at least have a sort of objective-C level of control over GC, it would make implementing native threaded applications far less... /hazy/ Just my two cents, but if the Chicken Team were to pursue this I'd like to see it as a major revision feature. IE, Chicken 5: now with very different GC behaviour! -Dan ___ Chicken-users mailing list Chicken-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-users
Re: [Chicken-users] Best way to share memory between C and Chicken
From: John Cowan co...@mercury.ccil.org Subject: Re: [Chicken-users] Best way to share memory between C and Chicken Date: Mon, 6 May 2013 08:21:34 -0400 Felix scripsit: Unfortunately, execution and garbage collection are tightly interleaved in the cheney-on-the-mta model. Minor collection is, but major collection could be run in a separate thread so that it can run concurrently (even on a second core) with the rest of the program. As it happens, I was reading about a concurrent GC just the other day which sounded interesting -- and just happens to be named Chicken, how cool is that? http://www.cs.technion.ac.il/~erez/Papers/real-time-pldi.pdf Nice. What a coincidence. I'll have to read it. But implementing a collector like this is such a major piece of work that I don't see this ever happening. It took years to get the current GC into a reliable state. Running the collector, even only for major collections concurrently will need numerous changes. Currently existing headers in oldspace are modified with a forwarding pointer and thus be invalidated during GC. Those forwarding pointers could perhaps be moved into a separate table, but things don't stop there. The mutator may destructively mutate already copied oldspace data - these mutations would need to be tracked and properly applied to the copies in newspace, and so on and so on. As Dan already pointed out, there are countless places where thread-safety suddenly becomes an issue. In short: give me six months, fully compensated and you get something that works like crap. :-) cheers, felix ___ Chicken-users mailing list Chicken-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-users
