func ExampleWithTimeout() {
// Pass a context with a timeout to tell a blocking function that it
// should abandon its work after the timeout elapses.
- ctx, _ := context.WithTimeout(context.Background(), 50*time.Millisecond)
+ ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
+
select {
case <-time.After(1 * time.Second):
fmt.Println("overslept")
case <-ctx.Done():
fmt.Println(ctx.Err()) // prints "context deadline exceeded"
}
+
+ // Even though ctx should have expired already, it is good
+ // practice to call its cancelation function in any case.
+ // Failure to do so may keep the context and its parent alive
+ // longer than necessary.
+ cancel()
+
// Output:
// context deadline exceeded
}