What are the best practices for using the context package in Go?

What are the best practices for using the context package in Go?

The context package in Go is essential for managing deadlines, cancellations, and request-scoped values. Best practices include using context.Context as the first parameter in your functions, avoiding passing values directly, and using context only for cancellation and timeout.

Can you give an example of how to implement a context with a timeout?

Sure! You can use context.WithTimeout to create a context that automatically cancels after a specified duration. Here's a simple example:

ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
defer cancel()

select {
case <-time.After(1 * time.Second):
    fmt.Println("Completed")
case <-ctx.Done():
    fmt.Println(ctx.Err())
}

What should I avoid when using the context package?

Avoid using context for passing optional parameters or for storing data that isn't related to cancellation or deadlines. Also, don't store the context in a struct or global variable.

How do I handle context cancellation in goroutines?

You can handle context cancellation in goroutines by checking the ctx.Done() channel. Here's an example:

func doWork(ctx context.Context) {
    select {
    case <-ctx.Done():
        fmt.Println("Work cancelled")
        return
    default:
        // Perform work
    }
}