veddan / rust-concurrent-hashmap Goto Github PK

We're using cargo audit in our project and today this vulnerability was found:

error: Vulnerable crates found!

ID:	 RUSTSEC-2019-0013
Crate:	 spin
Version: 0.4.8
Date:	 2019-08-27
URL:	 https://github.com/mvdnes/spin-rs/issues/65
Title:	 Wrong memory orderings in RwLock potentially violates mutual exclusion
Solution: upgrade to: >= 0.5.2

I will fork the project and try to see if just updating spin don't break anything and submit a PR if doesn't.

Adding a build status would be good.

Specifically

{
    let accessor = map.find(&x);
    map.insert(y, z);  // Is deadlock OK? What are the properties of std locks?
}

--> /home/suraj.prakash/.cargo/registry/src/github.com-1ecc6299db9ec823/spin-0.4.6/src/lib.rs:6:30
|
6 | #![cfg_attr(feature = "asm", feature(asm))]
| ^^^^^^^^^^^^^

error: aborting due to previous error

Caused by:
process didn't exit successfully: rustc --crate-name spin /home/suraj.prakash/.cargo/registry/src/github.com-1ecc6299db9ec823/spin-0.4.6/src/lib.rs --crate-type lib --emit=dep-info,link -C debuginfo=2 --cfg feature="asm" -C metadata=f0103624a0e8ce52 -C extra-filename=-f0103624a0e8ce52 --out-dir /home/suraj.prakash/projects/payu_concur/target/debug/deps -L dependency=/home/suraj.prakash/projects/payu_concur/target/debug/deps --cap-lints allow (exit code: 101)

This crate cannot be found on crates.io looking for "concurrent hash map". Maybe adding some tag would help.

Any formal description in Readme would be very helpful. Thanks

While experimenting with a non-default hasher and ConcHashMap, I found that the new method doesn't include the hasher in its type signature. As a result, code like the following:

type MyMap = ConcHashMap<(u64, u64), u8>;
...
let x: MyMap = MyMap::new();

doesn't compile because MyMap::new returns a type different than MyMap. This doesn't look intentional and is probably fixed simply by changing the return type of new from ConcHashMap<K, V> to ConcHashMap<K, V, H>.

An easy workaround is to import the Default trait and use MyMap::default() instead of MyMap::new().

Hi,

Do you have an example on how to use options concurrency, I'd like to increase the 16 to 256 but I can't find a working example, I can't understand the doc properly.

Thank you so much man.

RWLocks can be slow, Mutex might be faster. Obviously might depend on read/write ratio. Needs benchmarks.
Last time I checked, lots of time was spent doing virtual calls to access thread-locals (is_panicking) on low-contention scenarios, see rust-lang/rust#25088.