first commit

1 files changed, 35 insertions, 0 deletions

diff --git a/main.go b/main.go
new file mode 100644
index 0000000..ade5cce
--- /dev/null
+++ b/main.go
@@ -0,0 +1,35 @@
+package main
+
+import (
+	"fmt"
+	"sync"
+	"time"
+)
+
+func main() {
+	var (
+		jobs    = 20                 // Run 20 jobs in total.
+		running = make(chan bool, 3) // Limit concurrent jobs to 3.
+		wg      sync.WaitGroup       // Keep track of which jobs are finished.
+	)
+
+	wg.Add(jobs)
+	for i := 1; i <= jobs; i++ {
+		running <- true // Fill running; this will block and wait if it's already full.
+
+		// Start a job.
+		go func(i int) {
+			defer func() {
+				<-running // Drain running so new jobs can be added.
+				wg.Done() // Signal that this job is done.
+			}()
+
+			// "do work"
+			time.Sleep(1 * time.Second)
+			fmt.Println(i)
+		}(i)
+	}
+
+	wg.Wait() // Wait until all jobs are done.
+	fmt.Println("done")
+}