GO Goroutines and Concurrency 3

Question 1

What is a goroutine leak?

Accepted Answer

A goroutine that never terminates and is never garbage collected

Answer

A goroutine leak occurs when goroutines are started but never allowed to complete, accumulating and consuming resources until the program slows or crashes.

Question 2

What is the zero value of a `sync.Mutex`?

Accepted Answer

unlocked and ready to use

Answer

A zero-value `sync.Mutex` is an unlocked mutex ready for use, so no explicit initialization is needed.

Question 3

Which context function creates a context that can be cancelled manually?

Accepted Answer

context.WithCancel()

Answer

`context.WithCancel` returns a derived context and a `cancel` function; calling `cancel()` propagates cancellation to all goroutines watching that context.

Question 4

What happens if you call `cancel()` returned by `context.WithCancel` multiple times?

Accepted Answer

Only the first call has effect; subsequent calls are no-ops

Answer

Calling `cancel()` multiple times is safe; only the first call cancels the context and subsequent calls are no-ops.

Question 5

Which atomic operation in `sync/atomic` swaps a value only if it matches an expected value?

Accepted Answer

atomic.CompareAndSwapInt64

Answer

`atomic.CompareAndSwapInt64` atomically compares the current value with `old` and, if equal, sets it to `new`, returning whether the swap occurred.

GO - Golang Online Test Practice Test

GO - Golang Online Test Practice Test

GO Goroutines and Concurrency 3