Comments for "https://os.phil-opp.com/heap-allocation/"

[utterances-bot]

This is a general purpose comment thread for the Heap Allocation post.

[Mubelotix]

Thank you I was waiting this part !

[shakram02]

Hey Philipp, thank you for the great post ( as always ✌️ )

I wanted to note that I think now it's possible to move the allocator to its own module and out of lib.rs because of this PR.

Can't wait for your next tutorial!

[toothbrush7777777]

@phil-opp As @shakram02 noted, rust-lang/rust#62735 now makes it possible to define the global allocator in a submodule.

[phil-opp]

@shakram02 @toothbrush7777777 Thank you for reporting this and sorry for the late reply. I created #714 to move the #[global_allocator] into the allocator module in the post-10 branch and I will create a second pull request to update the blog text in a moment.

Edit: Blog update in #715.

[Menschenkindlein]

The comment in the first code block in https://os.phil-opp.com/heap-allocation/#the-global-allocator-attribute should be // in src/lib.rs.

[phil-opp]

@Menschenkindlein We recently moved the definition to the allocator module in #714. Try updating your Rust nightly if you get an error.

[Menschenkindlein]

I guess it doesn't need allocator:: then, does it?

[phil-opp]

Ah, good catch! Fixed in #728.

[GuillaumeDIDIER]

How do you handle memory allocation failure gracefully in here ? (If my users starts forkbombing I’d like to avoid crashing the kernel and instead tell the user nope, your fork is a spoon)

[phil-opp]

Currently the only way is to use the try_reserve method before appending to collections. I linked the method for Vec, but it also exists for the other collection types. These methods were introduced with the fallible collection allocation 1.0 RFC.

Alternatively, you could create your own alloc library that returns a result instead of panicking for all collection methods. Or, try to get unwinding working with your kernel so that you can catch the oom panic.

[GuillaumeDIDIER]

Going down the rabbit hole in stumbled onto https://github.com/vcombey/fallible_collections not sure if other such crate exist, but this looks like a reasonable thing to use, until hopefully the original alloc crate decides on how to play nice with people who need to handle memory allocation errors. (The ability to have the allocator specify an Error type with the default being ! would imho be very nice)