June 2018 Update

Task/Checkpoint-synchronization/Go/checkpoint-synchronization-1.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+    "log"
+    "math/rand"
+    "sync"
+    "time"
+)
+
+func worker(part string) {
+    log.Println(part, "worker begins part")
+    time.Sleep(time.Duration(rand.Int63n(1e6)))
+    log.Println(part, "worker completes part")
+    wg.Done()
+}
+
+var (
+    partList    = []string{"A", "B", "C", "D"}
+    nAssemblies = 3
+    wg          sync.WaitGroup
+)
+
+func main() {
+    rand.Seed(time.Now().UnixNano())
+    for c := 1; c <= nAssemblies; c++ {
+        log.Println("begin assembly cycle", c)
+        wg.Add(len(partList))
+        for _, part := range partList {
+            go worker(part)
+        }
+        wg.Wait()
+        log.Println("assemble.  cycle", c, "complete")
+    }
+}