🚀 Features

• feat: add MultiPool and MultiPoolWithFunc (#305)

🛩 Enhancements

• opt: fall back to LeastTasks when RoundRobin can't find a worker (#306)
• feat: add MultiPool and MultiPoolWithFunc (#305)
• refactor: enforce a few minor optimizations in code (#302)
• refactor: refine the code in retrieveWorker to make it more readable (#295)

🐛 Bugfixes

• bug: return the error from Pool.Submit/PoolWithFunc.Invoke accordingly (#297)
• bug: fix the potential goroutine leak after calling Release() (#287)

📚 Documentation

• chore: eliminate some useless content (#303)
• chore: update READMEs 16771ceb8fe801ee3679d590b84b762556264b71
• chore: add a new use case (#290)

🗃 Misc

• chore: eliminate some useless content (#303)
• chore: enable more title matchers for auto-labelers of bug and new feature (#300)
• chore: enable auto-labeler for PRs of updating semantic version (#298)
• chore: clean up some comments and CI yaml (#296)
• chore: bump up modules (#292)

Full Changelog: https://github.com/panjf2000/ants/compare/v2.8.0...v2.9.0

Performance improvement

In version v2.9.0, ants introduces two new pool types: MultiPool and MultiPoolWithFunc from which you will benefit the performance improvement on the basis of the fine-grained locking that reduces the lock contention.

These two pools are a good fit for the scenario where you have a large number of tasks to submit, and you don't want the single pool to be the bottleneck.

Benchmark testing

goos: darwin
goarch: arm64
pkg: github.com/panjf2000/ants/v2
BenchmarkAntsPool-10                   	       2	 777222500 ns/op	25458216 B/op	 1115895 allocs/op
BenchmarkAntsMultiPool-10              	       2	 667141666 ns/op	23590496 B/op	 1105121 allocs/op
BenchmarkAntsPoolThroughput-10         	       2	 747288979 ns/op	 9266236 B/op	  117693 allocs/op
BenchmarkAntsMultiPoolThroughput-10    	       2	 579771771 ns/op	 4550356 B/op	   66303 allocs/op
BenchmarkParallelAntsPoolThroughput-10         	 1405256	       801.3 ns/op	       9 B/op	       0 allocs/op
BenchmarkParallelAntsMultiPoolThroughput-10    	 2264618	       473.6 ns/op	       9 B/op	       0 allocs/op

Thanks to all these contributors: @ELchem, @POABOB and @panjf2000 for making this release possible.