goAsync race conditionMedium

Worker function not exiting properly causing timeouts

Time: 0:00

BugFind the bug and fix the code

What it should do

Start a worker that processes jobs until the context is done. Example: startWorker(ctx, jobs) -> nil

What happens instead

The worker function does not exit properly, causing timeouts and resource leaks.

package main

import (
	"context"
	"fmt"
	"time"
)

func startWorker(ctx context.Context, jobs <-chan int) {
	for job := range jobs {
		fmt.Println("Processing job", job)
		time.Sleep(time.Second)
	}
}

func main() {
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	jobs := make(chan int, 3)
	go startWorker(ctx, jobs)
	for i := 1; i <= 3; i++ {
		jobs <- i
	}
	close(jobs)
	<-ctx.Done()
}

Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).

⏱️0:00

Hints

🏆 0 hints = Flawless Solve

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Hint 3

Unlocks after Hint 2

This bug belongs to the async and race conditions pattern

A missing await, unbuffered channel deadlocks, ConcurrentModificationException, and data races under load.

Learn the async and race conditions pattern Step through your own code

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package main import ( "context" "fmt" "time" ) func startWorker(ctx context.Context, jobs <-chan int) { for job := range jobs { fmt.Println("Processing job", job) time.Sleep(time.Second) } } func main() { ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second) defer cancel() jobs := make(chan int, 3) go startWorker(ctx, jobs) for i := 1; i <= 3; i++ { jobs <- i } close(jobs) <-ctx.Done() }

Worker function not exiting properly causing timeouts

What it should do

What happens instead

More async and race conditions to practise

Worker function not exiting properly causing timeouts

What it should do

What happens instead

More async and race conditions to practise