SDK Conformance test - fix parallel recordRequests (googleforgames#1456)

Add Unit Test to cover the race condition.

Co-authored-by: Mark Mandel <markmandel@google.com>

pkg/sdkserver/localsdk.go

@@ -75,6 +75,7 @@ type LocalSDKServer struct {
 	gs                *sdk.GameServer
 	update            chan struct{}
 	updateObservers   sync.Map
+	testMutex         sync.Mutex
 	requestSequence   []string
 	expectedSequence  []string
 	gsState           agonesv1.GameServerState
@@ -90,6 +91,7 @@ func NewLocalSDKServer(filePath string) (*LocalSDKServer, error) {
 		gs:              defaultGs,
 		update:          make(chan struct{}),
 		updateObservers: sync.Map{},
+		testMutex:       sync.Mutex{},
 		requestSequence: make([]string, 0),
 		testMode:        false,
 		gsState:         agonesv1.GameServerStateScheduled,
@@ -164,6 +166,8 @@ func (l *LocalSDKServer) SetExpectedSequence(sequence []string) {
 // recordRequest append request name to slice
 func (l *LocalSDKServer) recordRequest(request string) {
 	if l.testMode {
+		l.testMutex.Lock()
+		defer l.testMutex.Unlock()
 		l.requestSequence = append(l.requestSequence, request)
 	}
 }
@@ -185,6 +189,8 @@ func (l *LocalSDKServer) recordRequestWithValue(request string, value string, ob
 		}
 
 		if value == fieldVal {
+			l.testMutex.Lock()
+			defer l.testMutex.Unlock()
 			l.requestSequence = append(l.requestSequence, request)
 		} else {
 			fmt.Printf("Error: we expected to receive '%s' as value for '%s' request but received '%s'. \n", fieldVal, request, value)

pkg/sdkserver/localsdk_test.go

@@ -17,6 +17,7 @@ package sdkserver
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"io/ioutil"
 	"os"
 	"sync"
@@ -380,3 +381,39 @@ func TestLocalSDKServerStateUpdates(t *testing.T) {
 	assert.Nil(t, err)
 	assert.Equal(t, gs.Status.State, string(agonesv1.GameServerStateShutdown))
 }
+
+// TestSDKConformanceFunctionality - run a number of record requests in parallel
+func TestSDKConformanceFunctionality(t *testing.T) {
+	t.Parallel()
+
+	l, err := NewLocalSDKServer("")
+	assert.Nil(t, err)
+	l.testMode = true
+	l.recordRequest("")
+	l.gs = &sdk.GameServer{ObjectMeta: &sdk.GameServer_ObjectMeta{Name: "empty"}}
+	exampleUID := "052fb0f4-3d50-11e5-b066-42010af0d7b6"
+	// field which is tested
+	setAnnotation := "setannotation"
+	l.gs.ObjectMeta.Uid = exampleUID
+
+	expected := []string{}
+	expected = append(expected, "", setAnnotation)
+
+	wg := sync.WaitGroup{}
+	for i := 0; i < 20; i++ {
+		wg.Add(1)
+		str := fmt.Sprintf("%d", i)
+		expected = append(expected, str)
+
+		go func() {
+			l.recordRequest(str)
+			l.recordRequestWithValue(setAnnotation, exampleUID, "UID")
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+
+	l.SetExpectedSequence(expected)
+	b := EqualSets(l.expectedSequence, l.requestSequence)
+	assert.True(t, b, "we should receive strings from all go routines %v %v", l.expectedSequence, l.requestSequence)
+}