[#388] trace: make WithTaskGroup actually concurrent

2020-11-22 15:14:26 +01:00
parent 61acc7494a
commit 0d96627ffb
2 changed files with 54 additions and 4 deletions
@@ -43,15 +43,19 @@ func WithTaskAndSpan(ctx context.Context, task string, span string) (context.Con
 }

 // create a span during which several child tasks are spawned using the `add` function
+//
+// IMPORTANT FOR USERS: Caller must ensure that the capturing behavior is correct, the Go linter doesn't catch this.
 func WithTaskGroup(ctx context.Context, taskGroup string) (_ context.Context, add func(f func(context.Context)), waitEnd DoneFunc) {
 	var wg sync.WaitGroup
 	ctx, endSpan := WithSpan(ctx, taskGroup)
 	add = func(f func(context.Context)) {
 		wg.Add(1)
-		defer wg.Done()
-		ctx, endTask := WithTask(ctx, taskGroup)
-		defer endTask()
-		f(ctx)
+		go func() {
+			defer wg.Done()
+			ctx, endTask := WithTask(ctx, taskGroup)
+			defer endTask()
+			f(ctx)
+		}()
 	}
 	waitEnd = func() {
 		wg.Wait()