3 ms·

It's still runtime memory management. That makes it garbage collection in my book. Sure it's not as involved as tracing, the prototypical form of GC, but it's s

It's still runtime memory management. That makes it garbage collection in my book. Sure it's not as involved as tracing, the prototypical form of GC, but it's still something that requires a runtime check each time that resource is used or a binding to it goes out of scope, similar to aspects in generational GC.

alblue 10y ago
The point is that while both reference counting and garbage collection are types of automatic memory management, the reverse isn't true. From a 1976 paper on automatic memory management https://www.cs.purdue.edu/homes/hosking/690M/deutsch.pdf https://www.cs.purdue.edu/homes/hosking/690M/deutsch.pdf "Automatic reclamation of storage no longer in use is done by the following two techniques: * Garbage collection * Reference counting" Note that these are two separate items and that one is not a subset of the other (and vice versa). It is simply incorrect to call reference counting "garbage collection" when the academic and industrial practices already have explicit meanings to these two terms.
- Manishearth 10y ago
  And http://dl.acm.org/citation.cfm?id=356854 http://dl.acm.org/citation.cfm?id=356854 (pdf: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.468.1717&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.468...) treats reference counting as a "way to distribute GC overhead time". I'm not saying the term always is used that way in academia. I'm saying that it's sometimes used that way, and that it's valid to call RC a form of GC. Ironically I said that RC was a form of GC to avoid precisely this argument, because if I say "Rust doesn't have GC" I'll have a bunch of folks telling me that RC is a form of GC. This is largely irrelevant to the point I was making, which explicitly distinguished between RC and tracing ("magic") GC -- which I suspected (but wasn't sure) was what was being asked about.

alblue 10y ago

The point is that while both reference counting and garbage collection are types of automatic memory management, the reverse isn't true. From a 1976 paper on automatic memory management https://www.cs.purdue.edu/homes/hosking/690M/deutsch.pdf https://www.cs.purdue.edu/homes/hosking/690M/deutsch.pdf "Automatic reclamation of storage no longer in use is done by the following two techniques: * Garbage collection * Reference counting" Note that these are two separate items and that one is not a subset of the other (and vice versa). It is simply incorrect to call reference counting "garbage collection" when the academic and industrial practices already have explicit meanings to these two terms.

Manishearth 10y ago
And http://dl.acm.org/citation.cfm?id=356854 http://dl.acm.org/citation.cfm?id=356854 (pdf: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.468.1717&rep=rep1&type=pdf http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.468...) treats reference counting as a "way to distribute GC overhead time". I'm not saying the term always is used that way in academia. I'm saying that it's sometimes used that way, and that it's valid to call RC a form of GC. Ironically I said that RC was a form of GC to avoid precisely this argument, because if I say "Rust doesn't have GC" I'll have a bunch of folks telling me that RC is a form of GC. This is largely irrelevant to the point I was making, which explicitly distinguished between RC and tracing ("magic") GC -- which I suspected (but wasn't sure) was what was being asked about.