_example: make Work a bit more erratic

_example/work.go

@@ -1,18 +1,34 @@
 package example
 
 import (
+	"context"
 	"fmt"
+	"math/rand"
 	"time"
 )
 
-// Work loops forever, generating a bunch of allocations of various sizes in
-// order to force the garbage collector to work.
+// Work loops forever, generating a bunch of allocations of various sizes, plus
+// some goroutines, in order to force the garbage collector to work.
 func Work() {
+	work(context.Background(), 0)
+}
+
+func work(ctx context.Context, lvl int) {
+	println("work", lvl)
 	m := make(map[int]interface{})
+	tick := time.NewTicker(10 * time.Millisecond)
+
 	for i := 0; ; i++ {
+		select {
+		case <-ctx.Done():
+			return
+		case <-tick.C:
+			break
+		}
 
 		var obj interface{}
-		switch i % 6 {
+
+		switch rand.Intn(10) % 10 {
 		case 0:
 			obj = &struct {
 				_ uint32
@@ -26,10 +42,20 @@ func Work() {
 			obj = fmt.Sprintf("a relatively long and useless string %d", i)
 		case 3:
 			obj = make([]byte, i%1024)
-		case 4:
+		case 4, 5:
 			obj = make([]byte, 10*i%1024)
-		case 5:
+		case 6, 7:
 			obj = make([]string, 512)
+		case 8:
+			obj = make([]byte, 16*1024)
+		case 9:
+			if lvl > 2 {
+				break
+			}
+			// Sometimes start another goroutine, just because...
+			ctx, cancel := context.WithTimeout(ctx, 15*time.Second)
+			defer cancel()
+			work(ctx, lvl+1)
 		}
 
 		if i == 1000 {
@@ -38,6 +64,5 @@ func Work() {
 		}
 
 		m[i] = obj
-		time.Sleep(10 * time.Millisecond)
 	}
 }