alt Hacker NewsIt's interesting that we've gone from cooperative to preemptive to cooperative multitasking again.
I agree that blocking threads is generally more natural / obvious. Cooperative multitasking was always done for performance reasons and more recently for simplicity (in single thread implementations with no locking) and/or scaling reasons.
Message passing concurrency is going even further though, and never really seems to have taken off wholistically. Again, primarily for performance reasons. When we do pass messages (across networks, too/from RAM or disk, etc) we usually add caching and other optimizations which make concurrency even harder to reason about.
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Message passing on virtual threads on the JVM allows you to run millions of threads and it has no performance downside to async.
> wholistically
You made me curious about the spelling of 'holistic', given that it really is based on the concept of wholeness. It turns out:
- Holistic is formed from the Greek root hol-, meaning "whole". Like hologram.
- It's even closer to the English than it looks; modern whole descends from Old English hal (cognate to the Greek word), which also gives us hale and health. The W in the modern spelling is a spurious addition unrelated to the etymology of the word. You'd expect "hole".
- Who is different, and the W in that word is etymologically correct. (Old English hwa.)
Message-passing is popular in HPC (e.g. MPI) because it more closely models how hardware works. But at a higher level people mostly prefer to build abstractions on top of it like async/await because message-passing requires you to manually compile your flows into per-process state machines, and that's not how most people think about flows (even though business people do sometimes: https://link.springer.com/chapter/10.1007/978-3-540-72863-4_...).