31–40 of 44 posts
I suppose I'll have to be the first to express shock that they decided to name it Folly. I feel like Poe's Law is expressing itself.
Earlier quoted context omitted.
Hmm, I recently created a private memory allocator so the discussion on the page is somewhat interesting... Only a tiny minority of objects are genuinely non-relocatable: Hmm, I'm not exactly what is meant here. Moving a block of memory from here to there in the most general case will leave your pointers dangling and crash you in no short order. Things that pointed to the data you moved just don't any more. If you ar…
Edit: I think the assumption is that an object itself is relocatable inside a container like vector if it marks itself as such. The document itself doesn't actually explain the inner workings.
Earlier quoted context omitted.
Modern heaps typically have some low-fragmentation technique built-in, for example, Windows ships with Low Fragmentation Heap, which is turned on by default since Vista.
What is "low-fragmentation heap"? Why would anyone want "high-fragmentation heap"? (since you imply that it's an option)
I'm Tudor, one of the main folly authors. I wrote format, Arena / ThreadCachedArena, DiscriminatedPtr, GroupVarint, TimeoutQueue, and various other pieces (parts of String.h, ThreadLocal, etc), and I'm pretty well-versed with the entire library so I can reasonably answer questions (or poke the appropriate people to make a HN account and answer). Ask away.
I'm Tudor, one of the main folly authors. I wrote format, Arena / ThreadCachedArena, DiscriminatedPtr, GroupVarint, TimeoutQueue, and various other pieces (parts of String.h, ThreadLocal, etc), and I'm pretty well-versed with the entire library so I can reasonably answer questions (or poke the appropriate people to make a HN account and answer). Ask away.
Not necessarily specific to Folly, but I've wondered why vector classes don't have a "short vector optimization" like string classes do. That is, why don't they store 24 bytes or so in place? Is it because the required iterators would take-up too much space anyway?
We might unify that with fbvector eventually.
Earlier quoted context omitted.
Modern heaps typically have some low-fragmentation technique built-in, for example, Windows ships with Low Fragmentation Heap, which is turned on by default since Vista.
What is "low-fragmentation heap"? Why would anyone want "high-fragmentation heap"? (since you imply that it's an option)
Also it puts consequently allocated objects (of different size) far away (and thus reduces cache locality), which, in turn may reduce performance for some "allocate a lot of stuff at the beginning and then serve it", etc scenarios, but this is pretty esoteric problem.
Benefits outweigh the concerns, so most apps benefit from the low-fragmentation heaps.
Earlier quoted context omitted.
given the business you run and the work you do for the Freebsd team Are you getting confused between tptacek and me?
Hey, why don't you use C++? :)