Clarify worker-pool example

Ref #131

examples/worker-pools/worker-pools.go

@@ -13,8 +13,9 @@ import "time"
 // simulate an expensive task.
 func worker(id int, jobs <-chan int, results chan<- int) {
     for j := range jobs {
-        fmt.Println("worker", id, "processing job", j)
+        fmt.Println("worker", id, "started  job", j)
         time.Sleep(time.Second)
+        fmt.Println("worker", id, "finished job", j)
         results <- j * 2
     }
 }
@@ -33,15 +34,15 @@ func main() {
         go worker(w, jobs, results)
     }
 
-    // Here we send 9 `jobs` and then `close` that
+    // Here we send 5 `jobs` and then `close` that
     // channel to indicate that's all the work we have.
-    for j := 1; j <= 9; j++ {
+    for j := 1; j <= 5; j++ {
         jobs <- j
     }
     close(jobs)
 
     // Finally we collect all the results of the work.
-    for a := 1; a <= 9; a++ {
+    for a := 1; a <= 5; a++ {
         <-results
     }
 }

examples/worker-pools/worker-pools.hash

@@ -1,2 +1,2 @@
-9d5b1d008d278df7db7697d56d491d982da86e7d
-y12QxBsKtT
+1f9acf1e50be05cad73e6b085ed3294892c67d42
+RTRcHA05vV

examples/worker-pools/worker-pools.sh

@@ -1,16 +1,17 @@
-# Our running program shows the 9 jobs being executed by
-# various workers. The program only takes about 3 seconds
-# despite doing about 9 seconds of total work because
+# Our running program shows the 5 jobs being executed by
+# various workers. The program only takes about 2 seconds
+# despite doing about 5 seconds of total work because
 # there are 3 workers operating concurrently.
 $ time go run worker-pools.go 
-worker 1 processing job 1
-worker 2 processing job 2
-worker 3 processing job 3
-worker 1 processing job 4
-worker 2 processing job 5
-worker 3 processing job 6
-worker 1 processing job 7
-worker 2 processing job 8
-worker 3 processing job 9
+worker 1 started  job 1
+worker 2 started  job 2
+worker 3 started  job 3
+worker 1 finished job 1
+worker 1 started  job 4
+worker 2 finished job 2
+worker 2 started  job 5
+worker 3 finished job 3
+worker 1 finished job 4
+worker 2 finished job 5
 
-real	0m3.149s
+real	0m2.358s