initial commit

cmd/repedative-queuing/main.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+	"time"
+)
+
+func main() {
+	// create channel for task
+	taskChannel := make(chan bool, 1)
+
+	// create wait-group
+	wg := new(sync.WaitGroup)
+
+	// wait for all tasks to finish
+	defer func(*sync.WaitGroup) {
+		wg.Wait()
+		fmt.Printf("All processes stopped, shutting down.\n")
+	}(wg)
+
+	// add the task to the wait-group
+	wg.Add(1)
+	// start task loop
+	go infiniteTask(wg, taskChannel, time.Duration(time.Second*5))
+
+	// keep program running until a shutdown signal is received
+	forever(taskChannel)
+}
+
+func forever(collector chan<- bool) {
+	// create signal channel
+	s := make(chan os.Signal, 1)
+	signal.Notify(s, syscall.SIGTERM, syscall.SIGINT)
+
+	// wait for signal
+	sig := <-s
+	fmt.Printf("\nstarting shutdown procedure, detected signal: %s\n", sig)
+
+	// send shutdown to collector
+	collector <- true
+}
+
+func infiniteTask(wg *sync.WaitGroup, shutdown <-chan bool, timeout time.Duration) {
+	// set initial time length
+	t := time.NewTimer(timeout)
+	// stop the time when the process ends
+	defer t.Stop()
+
+	// start infinite loop
+	for {
+		select {
+		// catch timer signal
+		case <-t.C:
+			// trigger task
+			doTask()
+			// reset timer
+			t.Reset(timeout)
+		// catch shutdown signal
+		case <-shutdown:
+			fmt.Printf("Collector Stopped\n")
+			// clear the task from the wait-group
+			wg.Done()
+			// end the loop
+			return
+		// non-blocking channel receiver to allow for checking of either signal
+		default:
+			// wait 1 second to keep the program from eating un-necessary cycles
+			time.Sleep(time.Second * 1)
+		}
+	}
+}
+
+func doTask() {
+	fmt.Printf("Starting task\n")
+	time.Sleep(time.Second * 30)
+	fmt.Printf("Task finished\n")
+}

go.mod

@@ -0,0 +1,3 @@
+module example.com/examples
+
+go 1.20