https://cassiobotaro.dev/en/tags/semaphore/Recent content in Semaphore on cassiobotaroHugoenMon, 26 Oct 2026 19:53:30 -0300https://cassiobotaro.dev/en/posts/go-concurrency-semaphore/Thu, 29 Oct 2026 00:00:00 -0300https://cassiobotaro.dev/en/posts/go-concurrency-semaphore/<video src="https://cassiobotaro.dev/videos/semaforo.mp4" title="Ten tasks competing for three slots" aria-label="Ten tasks competing for three slots" autoplay loop muted playsinline controls preload="metadata" style="width: 100%; height: auto;"> </video> <p>In the <a href="https://cassiobotaro.dev/en/posts/go-concurrency-worker-pool/" >worker pool</a> I fixed how many goroutines exist. In <a href="https://cassiobotaro.dev/en/posts/go-concurrency-backpressure/" >backpressure</a> a channel&rsquo;s capacity held the producer back.</p> <p>But what if I have ten files to download, and the server kicks out anyone who opens more than three connections? I want one goroutine per file, and only three of them downloading at the same time.</p>