execute: use goroutines + mutex to more efficiently serialize non-async cases

cmd/execute.go

@@ -22,7 +22,9 @@ THE SOFTWARE.
 package cmd
 
 import (
+	"fmt"
 	"sync"
+	"time"
 
 	"gitea.elkins.co/Networking/ccl/internal/pkg/command"
 	"gitea.elkins.co/Networking/ccl/internal/pkg/container"
@@ -31,12 +33,27 @@ import (
 
 func execForEach(tgts []container.Container, getSet func(*container.Container) command.CommandSet) {
 	var wg sync.WaitGroup
+	var ser sync.Mutex // serialize non-async containers
 	for i := range tgts {
-		async := !tgts[i].StartOrder.Valid
-		runSet := func(cont *container.Container) {
+		async := tgts[i].StartOrder.ValueOrZero() == 0
+		wg.Add(1)
 		if async {
-				defer wg.Done()
+			// TODO: need to log errors on this branch
+			go runSet(&tgts[i], getSet, &wg)
+		} else {
+			ser.Lock()
+			go func(cont *container.Container, ser *sync.Mutex) {
+				defer ser.Unlock()
+				runSet(cont, getSet, &wg)
+				time.Sleep(5 * time.Second)
+			}(&tgts[i], &ser)
 		}
+	}
+	wg.Wait()
+}
+
+func runSet(cont *container.Container, getSet func(*container.Container) command.CommandSet, wg *sync.WaitGroup) {
+	defer wg.Done()
 	set := getSet(cont)
 	for _, cmd := range set.Commands {
 		if err := cmd.Execute(output, fake, set.ID); err != nil {
@@ -48,13 +65,13 @@ func execForEach(tgts []container.Container, getSet func(*container.Container) c
 		}
 	}
 }
-		if async {
-			wg.Add(1)
-			go runSet(&tgts[i])
-		} else {
-			runSet(&tgts[i])
+
+// For debugging
+func printConts(conts []container.Container) {
+	names := []string{}
+	for i := range conts {
+		names = append(names, fmt.Sprintf("[%s %d]", conts[i].Name, conts[i].StartOrder.ValueOrZero()))
 	}
-	}
-	wg.Wait()
+	fmt.Printf("%v\n", names)
 }