Selgitage, mis on blokeerivad kõned goroutine'ide töös ja kuidas need mõjutavad programmi täitmist

Blocking calls are operations that, when executed, stop (block) the current goroutine until the operation completes. In the context of goroutines in Go, if a goroutine makes a blocking call, it will not continue execution until the call finishes.

This affects the program such that if the blocking call is made in the main goroutine, it will wait, which can lead to delays or freezes. However, because goroutines are lightweight and many can be started, blocking calls in one goroutine do not block the execution of others.

An example of a blocking call is reading from a channel when no data is available:

ch := make(chan int)

func main() {
    go func() {
        ch <- 42 // sending a value
    }()
    val := <-ch // blocking call, waits to receive the value
    fmt.Println(val)
}

Here, the read operation from the channel blocks the main goroutine until a value arrives.