Hybrid Meetup #35 wrap-up | Leipzig Gophers

Cgo experiments

Hybrid meetup #35 took place 2023-04-18 19:00 at Basislager Leipzig and was all about Cgo.

Cgo allows to bridge C and Go. From C, we can connect to other languages, like C++, too. Use cases are legacy code or performance. Implementing a pseudo-random walk (using an LCG) in both Go and C shows that C can be up to 4x faster for this particular task.

 C               1         -1 29.553µs
GO               1         -1 84.303µs
 C            1000        -12 41.799µs
GO            1000         26 107.295µs
 C         1000000      -1810 22.837387ms
GO         1000000         -2 83.182797ms
 C      1000000000      15894 6.25975724s
GO      1000000000     -44632 25.620427056s

One example was concerned with wrapping ggml, a lightweight tensor library for machine learning - xcgoggml. A threading mystery remains.

Experiment details can be found here: https://github.com/miku/cgosamples

Zig cross-compilation

The zig compiler (LLVM) can build real staticly linked binaries from a Go project with C dependencies, such as sqlite3. Example repo: https://github.com/klingtnet/cross-compile-with-zigcc.

Misc

Cgo is a not Go, many guarantees are given up, maintenance of mixed C and Go code is much more difficult - rather than use CGO, maybe a grpc or other interface may keep C and Go world better separated
To wrap C++, we need to create a C façade
Go has a nice ast
GRPC performance in Go may suffer, if interfaces are used (due to overhead of reflection)
oapi-codegen is an openapi code generator for Go (and an alternative to the swagger tool)
Go’s type system can be limiting, when working with Web APIs or SDKs
Simple Markup Language
Parsec, Participle
YAML/HELL
Using symbols straight from a dynamic library via dlopen
A rundown of a benchmark across Python, C, and BLAS, for a HPC and competetive programming blog: https://en.algorithmica.org/hpc/complexity/languages/
Unbuffered terminal output in Go is slow. Try to wrap os.Stdout in a bufio.Writer if you need to print a lot of text.

We also briefly discussed LLMs, as we ran alpaca model ggml-alpaca-7b-q4.bin in the background, which wrote some simple SQL and thought of a haiku about the Go programming language:

Did you find a nice haiku?

Join our meetup and let us know!