https://github.com/felixge/gounwind

Experimental go stack unwinding using frame pointers.
https://github.com/felixge/gounwind

Last synced: about 2 months ago
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Experimental go stack unwinding using frame pointers.

• Host: GitHub
• URL: https://github.com/felixge/gounwind
• Owner: felixge
• Created: 2021-03-11T17:01:13.000Z (almost 4 years ago)
• Default Branch: main
• Last Pushed: 2023-01-27T20:01:32.000Z (almost 2 years ago)
• Last Synced: 2024-10-11T15:18:49.072Z (2 months ago)
• Language: Go
• Size: 9.77 KB
• Stars: 27
• Watchers: 3
• Forks: 3
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# gounwind

gounwind is a tiny Go library that acts as a drop-in replacement for [`runtime.Callers()`](https://golang.org/pkg/runtime/#Callers). It exists to show how simple and fast stack unwinding can theoretically be when using frame pointers.

Compared to `runtime.Callers()`, gounwind is:

- ~50 faster

- [~25 lines of code](./gounwind.go) vs [thousands](https://github.com/golang/go/blob/go1.16.2/src/runtime/traceback.go#L76-L559)

- Totally unsafe for production use

- Unable to recognize inlined functions

- Only works on 64 bit platforms [where frame pointers are enabled](https://github.com/golang/go/blob/go1.16.2/src/runtime/runtime2.go#L1108)

## Benchmark

The benchmark below shows the performance for unwinding a stack that has 16 frames. The numbers are from my macOS machine and Docker for Linux gives me very similar results.

```

goos: darwin

goarch: amd64

pkg: github.com/felixge/gounwind

cpu: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz

BenchmarkUnwind

BenchmarkUnwind/runtime

BenchmarkUnwind/runtime-12         	1281306	      934.7 ns/op

BenchmarkUnwind/gounwind

BenchmarkUnwind/gounwind-12        	65443237	       17.69 ns/op

```

## More Information

The [The Go low-level calling convention on x86-64](https://dr-knz.net/go-calling-convention-x86-64.html) article as well as [this video](https://www.youtube.com/watch?v=PrDsGldP1Q0) were incredibly useful to me while trying to figure this out.

Go includes frame pointers by default [since Go 1.7](https://github.com/golang/go/issues/15840).

There is [ongoing work](https://github.com/golang/go/issues/16638) to implement frame pointer unwinding for the Go core.