Go: Squeezing Stop-The-World Pauses Out of Crypto and Concurrency
Today's activity centers on shrinking hidden latency costs across the standard library — from garbage collector pauses in hashing to lock contention in canceled contexts and bubble-related test failures in synctest. Two near-duplicate crypto PRs from the same author tackle the same root cause on the same day.
Duration: PT2M34S
Episode overview
This episode is a short developer briefing from Go.
It explains recent repository work in plain language.
- Show: Go
- Published: 2026-08-17T13:06:15Z
- Audio duration: PT2M34S
Transcript excerpt
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You're listening to Go, the developer briefing for August 17th, 2026.
Today's theme is latency you don't see until it hurts: garbage collector pauses, lock contention, and race conditions between concurrency primitives.
Start with crypto. PRs 80916 and 80917, both from Alex Sharov, address the same problem twice in one day — sha1 and sha512 hashing large buffers can freeze every goroutine in the process for tens of milliseconds, because the assembly code processing blocks isn't preemptible. On a 64 megabyte buffer, worst-case…
Second theme: lock contention and shared state causing subtle bugs. PR 80915 found that every canceled context in a Go program shares a single lock, because the Done channel is created lazily and defaults to one shared package-level channel. That makes canceled-context checks slower than they need to be under…
One more note: a commit from Günther Noack adds Landlock sandboxing support for exec calls on Linux, letting programs restrict their own privileges before running a child process. That's a security-hardening feature, not a bug fix, and it's been in progress for a while under issue 68595.
What to remember: assembly-heavy standard library code is getting…
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