What does the garbage collector (GC) in Go do, and when does it usually turn on automatically? It frees memory of unreachable objects and runs automatically when the heap size exceeds the runtime threshold. It arranges variable placement in memory for cache optimization and triggers strictly on a timer every 10 ms. It tracks the number of goroutines and only activates after the main function finishes. It synchronizes mutex operations and activates when free RAM drops below 5%.

Garbage collector (GC) in Go is responsible for automatically freeing memory occupied by objects that are no longer referenced (unreachable objects). This helps prevent memory leaks and manage memory usage without manual intervention.

GC is usually enabled automatically when the size of the allocated memory (heap) exceeds a certain threshold set by the runtime. Thus, garbage collection is triggered as the heap grows to free up memory and maintain efficient resource usage.

Other options, such as timer-based triggers, goroutine tracking, or mutex synchronization, are not related to the GC functions in Go.