Make sure the mutex is unlocked before promise.set_value

src/infer_payload.cc

@@ -42,9 +42,10 @@ InferPayload::SetValue(std::unique_ptr<InferResponse> infer_response)
   // Only set value to the promise with the first response. Call the callback
   // function to send decoupled response to the stub.
   {
-    std::lock_guard<std::mutex> lock(mutex_);
+    std::unique_lock<std::mutex> lock(mutex_);
     if (!is_promise_set_) {
       is_promise_set_ = true;
+      lock.unlock();
       promise_->set_value(std::move(infer_response));
       return;
     }