Goroutines: the dark side of the runtime
summary
Explains that goroutines run on a fixed number of OS threads via the M P G scheduler, shows a real example where a loop with a closure capturing loop variable prints ten identical values, and demonstrates a subtle live lock where a tight for loop with an outer byte counter prevents GC because goroutines are preemption only at safe points, causing endless garbage collection. Shows practical fixes: copy loop vars, introduce checkpoints (channel ops, go, noinline), and adopt context for cooperative cancellation, while noting the runtime cannot forcibly kill goroutines.
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chapters (10)
- 0:00Intro
- 1:50Why Go
- 3:04Surprises
- 11:20MGP model
- 13:45Issues with goroutines
- 16:20The trick
- 20:12Debugging
- 23:11Stop a goroutine
- 24:45PHP
- 30:15QA
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