Update rules in concurrency for flow qps example. (#344)

Author: louyuting

example/flow/qps/qps_limit_example.go

@@ -15,7 +15,6 @@
 package main
 
 import (
-	"fmt"
 	"log"
 	"math/rand"
 	"time"
@@ -25,9 +24,10 @@ import (
 	"github.com/alibaba/sentinel-golang/core/config"
 	"github.com/alibaba/sentinel-golang/core/flow"
 	"github.com/alibaba/sentinel-golang/logging"
-	"github.com/alibaba/sentinel-golang/util"
 )
 
+const resName = "example-flow-qps-resource"
+
 func main() {
 	// We should initialize Sentinel first.
 	conf := config.NewDefaultConfig()
@@ -40,7 +40,7 @@ func main() {
 
 	_, err = flow.LoadRules([]*flow.Rule{
 		{
-			Resource:               "some-test",
+			Resource:               resName,
 			TokenCalculateStrategy: flow.Direct,
 			ControlBehavior:        flow.Reject,
 			Threshold:              10,
@@ -53,17 +53,15 @@ func main() {
 	}
 
 	ch := make(chan struct{})
-
 	for i := 0; i < 10; i++ {
 		go func() {
 			for {
-				e, b := sentinel.Entry("some-test", sentinel.WithTrafficType(base.Inbound))
+				e, b := sentinel.Entry(resName, sentinel.WithTrafficType(base.Inbound))
 				if b != nil {
 					// Blocked. We could get the block reason from the BlockError.
 					time.Sleep(time.Duration(rand.Uint64()%10) * time.Millisecond)
 				} else {
 					// Passed, wrap the logic here.
-					fmt.Println(util.CurrentTimeMillis(), "passed")
 					time.Sleep(time.Duration(rand.Uint64()%10) * time.Millisecond)
 
 					// Be sure the entry is exited finally.
@@ -73,5 +71,23 @@ func main() {
 			}
 		}()
 	}
+
+	// Simulate a scenario in which flow rules are updated concurrently
+	go func() {
+		time.Sleep(time.Second * 10)
+		_, err = flow.LoadRules([]*flow.Rule{
+			{
+				Resource:               resName,
+				TokenCalculateStrategy: flow.Direct,
+				ControlBehavior:        flow.Reject,
+				Threshold:              80,
+				StatIntervalInMs:       1000,
+			},
+		})
+		if err != nil {
+			log.Fatalf("Unexpected error: %+v", err)
+			return
+		}
+	}()
 	<-ch
 }

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/fsnotify/fsnotify v1.4.7
 	github.com/google/uuid v1.1.1
 	github.com/pkg/errors v0.9.1
-	github.com/shirou/gopsutil v3.20.11
+	github.com/shirou/gopsutil v3.20.11+incompatible
 	github.com/stretchr/testify v1.5.1
 	go.uber.org/multierr v1.5.0
 	gopkg.in/yaml.v2 v2.2.8

go.sum

@@ -16,6 +16,8 @@ github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
+github.com/shirou/gopsutil v3.20.11+incompatible h1:LJr4ZQK4mPpIV5gOa4jCOKOGb4ty4DZO54I4FGqIpto=
+github.com/shirou/gopsutil v3.20.11+incompatible/go.mod h1:5b4v6he4MtMOwMlS0TUMTu2PcXUg8+E1lC7eC3UO/RA=
 github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=