Async: only notify watchers once when Future::setFinished() is called multiple times

1 files changed, 3 insertions, 0 deletions

diff --git a/async/src/future.h b/async/src/future.h
index 75669ba..b580b5a 100644
--- a/async/src/future.h
+++ b/async/src/future.h
@@ -57,6 +57,9 @@ class FutureGeneric : public FutureBase
 public:
     void setFinished()
     {
+        if (d->finished) {
+            return;
+        }
         d->finished = true;
         for (auto watcher : d->watchers) {
             if (watcher) {