fixed race conditions

Signed-off-by: Aleksandr Dubovikov <d.lexand@gmail.com>

mediaapi/routing/url_preview.go

@@ -56,14 +56,14 @@ func makeUrlPreviewHandler(
 	go func() {
 		for {
 			t := time.Now().Unix()
+			urlPreviewCache.Lock()
 			for k, record := range urlPreviewCache.Records {
 				if record.Created < (t - int64(cfg.UrlPreviewCacheTime)) {
-					urlPreviewCache.Lock.Lock()
 					delete(urlPreviewCache.Records, k)
-					urlPreviewCache.Lock.Unlock()
 				}
 			}
-			time.Sleep(time.Duration(16) * time.Second)
+			urlPreviewCache.Unlock()
+			time.Sleep(time.Duration(60) * time.Second)
 		}
 	}()
 
@@ -115,9 +115,9 @@ func makeUrlPreviewHandler(
 						Created: time.Now().Unix(),
 						Preview: urlPreviewCached,
 					}
-					urlPreviewCache.Lock.Lock()
+					urlPreviewCache.Lock()
 					urlPreviewCache.Records[pUrl] = urlPreviewCacheItem
-					defer urlPreviewCache.Lock.Unlock()
+					defer urlPreviewCache.Unlock()
 				}
 			}()
 
@@ -155,9 +155,9 @@ func makeUrlPreviewHandler(
 				}
 			}
 
-			urlPreviewCache.Lock.Lock()
+			urlPreviewCache.Lock()
 			urlPreviewCache.Records[pUrl] = urlPreviewCacheItem
-			defer urlPreviewCache.Lock.Unlock()
+			defer urlPreviewCache.Unlock()
 
 			activeUrlPreviewRequests.Lock()
 			activeUrlPreviewRequests.Url[pUrl].Cond.Broadcast()

mediaapi/routing/url_preview_test.go

@@ -190,6 +190,7 @@ func Test_ActiveRequestWaiting(t *testing.T) {
 	}
 
 	successResults := 0
+	successResultsLock := &sync.Mutex{}
 
 	for i := 0; i < 3; i++ {
 		go func() {
@@ -197,6 +198,8 @@ func Test_ActiveRequestWaiting(t *testing.T) {
 				if res.Code != 200 {
 					t.Errorf("Unsuccess result: %v", res)
 				}
+				successResultsLock.Lock()
+				defer successResultsLock.Unlock()
 				successResults++
 				return
 			}
@@ -205,9 +208,11 @@ func Test_ActiveRequestWaiting(t *testing.T) {
 	}
 
 	time.Sleep(time.Duration(1) * time.Second)
+	successResultsLock.Lock()
 	if successResults != 0 {
 		t.Error("Subroutines didn't wait")
 	}
+	successResultsLock.Unlock()
 	activeRequests.Url["someurl"].Cond.Broadcast()
 	to := time.After(1 * time.Second)
 	for {
@@ -217,9 +222,11 @@ func Test_ActiveRequestWaiting(t *testing.T) {
 			return
 		default:
 		}
+		successResultsLock.Lock()
 		if successResults == 3 {
 			break
 		}
+		successResultsLock.Unlock()
 	}
 }
 

mediaapi/types/types.go

@@ -101,7 +101,7 @@ type ActiveThumbnailGeneration struct {
 }
 
 type UrlPreviewCache struct {
-	Lock    sync.Mutex
+	sync.Mutex
 	Records map[string]*UrlPreviewCacheRecord
 }