In Go, the context
package helps manage request-scoped values, cancellation signals, and deadlines.
Two common ways to start a context are context.TODO()
and context.Background()
.
Though they behave similarly, they serve different purposes.
context.Background()
context.Background()
is the default when you don’t need any special handling (like cancellation or deadlines).
It's often used in main
, init
, or when initializing operations that don't need a more specific context.
Example:
func main() {
ctx := context.Background()
server := http.Server{Addr: ":8080", BaseContext: func(net.Listener) context.Context {
return ctx
}}
log.Fatal(server.ListenAndServe())
}
In this example, context.Background()
is used to establish a base context for the HTTP server.
context.TODO()
context.TODO()
is a placeholder context. Use it when you're unsure of what context to provide or when planning to refactor later.
Example:
func processOrder() {
ctx := context.TODO() // Placeholder, decision on context pending
err := db.SaveOrder(ctx, orderData)
if err != nil {
log.Println("Failed to save order:", err)
}
}
Here, context.TODO()
is temporarily used for a database operation until a more specific context is defined.
Key Differences
Both functions return an empty context, but they express different intentions:
-
context.Background()
: Used when you're confident no special context features are needed. -
context.TODO()
: A temporary placeholder context, signaling future changes.
Conclusion
When to Use context.Background()
:
- When initializing core services like HTTP servers or database connections.
- When there's no need for cancellation, deadlines, or values.
When to Use context.TODO()
:
- When refactoring, and you haven’t decided on the context yet.
- When implementing early-stage code that requires future improvements.
Top comments (1)
Short and useful, thanks.