How the Go Garbage Collector Works

The Go garbage collector is a concurrent, non-blocking, tri-color mark-and-sweep system that automatically reclaims memory by identifying live objects and freeing unreachable ones. It runs in parallel with your program, using write barriers to track object references without stopping the world for long periods.

// The GC runs automatically; you can trigger it manually for testing:
runtime.GC()

For C interoperability (cgo), the GC cannot see C-allocated memory, so you must use runtime.SetFinalizer to free C resources when Go objects are collected. Conversely, if C code holds pointers to Go objects, you must keep a Go-side reference alive until C is done to prevent premature collection.

The Go garbage collector is like an automated janitor that constantly scans your program's memory to find and clean up unused data. It works in the background without stopping your application, ensuring you don't run out of memory or have to manually delete variables. This keeps your code safe and simple, though you must be careful when mixing Go with C code since the janitor can't see into the C world.