Retrofitting Concurrency – Lessons from the Engine Room

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" summary

OCaml 5.0 brings native concurrency and parallelism and ships effect handlers as the language-level mechanism; the Multicore design uses per-domain minor heaps with a concurrent major GC after abandoning an initial read-barrier scheme that broke CFFI. The memory model has only atomic/nonatomic locations with DRF-SC and shows <1% overhead on x86. Tooling includes Sandmark continuous benchmarks, OPAM health checks, RR record/replay, ThreadSanitizer support and always-on CTF tracing; the async IO library competes with Go/Rust.

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" chapters (17)

1. 0:00Intro
2. 1:52In the year 2014...
3. 2:47Eliminate the runtime lock
4. 3:09Retrofitting Challenges ~ Approach
5. 5:25Parallel Allocator & GC
6. 6:15Access remote objects
7. 11:10Back to the drawing board (~2019)
8. 12:44Data Races
9. 13:48Second-mover Advantage
10. 15:45OCaml memory model (~2017)
11. 17:43Concurrency (~2015)
12. 24:03Ease of comprehension ~ Impact
13. 26:59Care for Users
14. 28:27Benchmarking
15. 31:52Invest in tooling
16. 36:36Growing the language
17. 37:29Where do we go from here?

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