From 909dc02b229f20b52b454c4142b2f7b39187f4ab Mon Sep 17 00:00:00 2001
From: levlam <levlam@telegram.org>
Date: Fri, 5 Jun 2020 06:52:55 +0300
Subject: [PATCH] Fix stopping of MultiPromiseActor only after and not before
 it is used again after setting result.

GitOrigin-RevId: 9c7895906911d75b3a8d6077eba113814070df23
---
 tdactor/td/actor/MultiPromise.cpp | 13 ++++++++++++-
 tdactor/td/actor/MultiPromise.h   |  3 +++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/tdactor/td/actor/MultiPromise.cpp b/tdactor/td/actor/MultiPromise.cpp
index 07184f1e8..beed4d2a8 100644
--- a/tdactor/td/actor/MultiPromise.cpp
+++ b/tdactor/td/actor/MultiPromise.cpp
@@ -10,6 +10,7 @@ namespace td {
 
 void MultiPromiseActor::add_promise(Promise<Unit> &&promise) {
   promises_.emplace_back(std::move(promise));
+  LOG(DEBUG) << "Add promise #" << promises_.size() << " to " << name_;
 }
 
 Promise<Unit> MultiPromiseActor::get_promise() {
@@ -24,11 +25,13 @@ Promise<Unit> MultiPromiseActor::get_promise() {
 
   future.set_event(EventCreator::raw(actor_id(), nullptr));
   futures_.emplace_back(std::move(future));
+  LOG(DEBUG) << "Get promise #" << futures_.size() << " for " << name_;
   return PromiseCreator::from_promise_actor(std::move(promise));
 }
 
 void MultiPromiseActor::raw_event(const Event::Raw &event) {
   received_results_++;
+  LOG(DEBUG) << "Receive result #" << received_results_ << " out of " << futures_.size() << " for " << name_;
   if (received_results_ == futures_.size()) {
     if (!ignore_errors_) {
       for (auto &future : futures_) {
@@ -47,13 +50,21 @@ void MultiPromiseActor::set_ignore_errors(bool ignore_errors) {
 }
 
 void MultiPromiseActor::set_result(Result<Unit> &&result) {
+  result_ = std::move(result);
+  stop();
+}
+
+void MultiPromiseActor::tear_down() {
+  LOG(DEBUG) << "Set result for " << promises_.size() << " promises in " << name_;
+
   // MultiPromiseActor should be cleared before it begins to send out result
   auto promises_copy = std::move(promises_);
   promises_.clear();
   auto futures_copy = std::move(futures_);
   futures_.clear();
   received_results_ = 0;
-  stop();
+  auto result = std::move(result_);
+  result_ = Unit();
 
   if (!promises_copy.empty()) {
     for (size_t i = 0; i + 1 < promises_copy.size(); i++) {
diff --git a/tdactor/td/actor/MultiPromise.h b/tdactor/td/actor/MultiPromise.h
index d231cafd5..84414c05c 100644
--- a/tdactor/td/actor/MultiPromise.h
+++ b/tdactor/td/actor/MultiPromise.h
@@ -77,9 +77,12 @@ class MultiPromiseActor final
   vector<FutureActor<Unit>> futures_;  // futures waiting for result of the queries
   size_t received_results_ = 0;
   bool ignore_errors_ = false;
+  Result<Unit> result_;
 
   void raw_event(const Event::Raw &event) override;
 
+  void tear_down() override;
+
   void on_start_migrate(int32) override {
     UNREACHABLE();
   }