👀 Views: 2584 💬 Answers: 1 📅 Created: 2025-06-22

go context http goroutines Go

I need help solving I'm facing an issue with Go's `context` package where the context cancellation doesn't seem to propagate as expected when used with goroutines in my HTTP handlers. My application uses Go 1.19 and I'm trying to implement a cancellation mechanism for requests that may take too long to process. Here's a simplified version of the code: ```go package main import ( "context" "fmt" "net/http" "time" ) func longRunningTask(ctx context.Context) { select { case <-time.After(5 * time.Second): // simulating a long task fmt.Println("Task completed") case <-ctx.Done(): fmt.Println("Task cancelled") } } func handler(w http.ResponseWriter, r *http.Request) { ctx, cancel := context.WithTimeout(r.Context(), 2*time.Second) defer cancel() go longRunningTask(ctx) // Simulating request processing time.Sleep(3 * time.Second) fmt.Fprintln(w, "Request processed") } func main() { http.HandleFunc("/longtask", handler) http.ListenAndServe(":8080", nil) } ``` When I make a request to `/longtask`, I expect the `longRunningTask` to be cancelled after 2 seconds, but it seems to continue running and prints "Task completed" after 5 seconds instead. I've tried using `context.WithTimeout`, but it appears that the goroutine initiated inside the handler doesn't respect the cancellation signal. Is there something I'm missing regarding context propagation in goroutines? Any insights or best practices to ensure that the context cancellation works as intended would be greatly appreciated. Has anyone dealt with something similar?