hyperium/hyper — pull request #161 by seanmonstar (2014-11-29 21:25:44+00:00)
Title: refactor(headers): changed from rwlock to mucell underneath

Before:
```
test header::tests::bench_header_get ... bench: 430 ns/iter (+/- 18)
test header::tests::bench_header_get_miss ... bench: 153 ns/iter (+/- 3)
test header::tests::bench_header_has ... bench: 184 ns/iter (+/- 6)
test header::tests::bench_header_set ... bench: 1102 ns/iter (+/- 14)
test header::tests::bench_header_view_is ... bench: 33 ns/iter (+/- 1)
```

After:
```
test header::tests::bench_header_get ... bench: 191 ns/iter (+/- 14)
test header::tests::bench_header_get_miss ... bench: 151 ns/iter (+/- 13)
test header::tests::bench_header_has ... bench: 182 ns/iter (+/- 32)
test header::tests::bench_header_set ... bench: 283 ns/iter (+/- 8)
test header::tests::bench_header_view_is ... bench: 33 ns/iter (+/- 0)
```

However, I'm not sure how much this differs from just using RefCell, as I think most of the speed up is not using OS locks.