GO Goroutines and Concurrency

Question 1

What keyword is used to start a goroutine in Go?

Accepted Answer

go

Answer

The `go` keyword before a function call launches it as a goroutine, running concurrently with other goroutines.

Question 2

What is the primary purpose of the `sync.WaitGroup` in Go?

Accepted Answer

Wait for a collection of goroutines to finish

Answer

`sync.WaitGroup` blocks the calling goroutine until all goroutines tracked via `Add`, `Done`, and `Wait` have completed.

Question 3

Which package provides the `Mutex` type for protecting shared state in Go?

Accepted Answer

sync

Answer

The `sync` package provides `Mutex` and `RWMutex` for safe concurrent access to shared data.

Question 4

What happens when a goroutine panics and the panic is not recovered?

Accepted Answer

The entire program crashes

Answer

An unrecovered panic in any goroutine terminates the entire Go program, not just that goroutine.

Question 5

Which function returns the number of logical CPUs available to the current process?

Accepted Answer

runtime.NumCPU()

Answer

`runtime.NumCPU()` returns the number of logical CPUs on the machine, while `GOMAXPROCS` sets/gets the limit used by the scheduler.

GO - Golang Online Test Practice Test