From 65d22c46d9955041baad11a5dbd9a2c8c21beaf9 Mon Sep 17 00:00:00 2001
From: neodiX42 <namlem@gmail.com>
Date: Wed, 4 Oct 2023 21:56:33 +0300
Subject: [PATCH] Rework locking mechanism in blockchain-explorer. (#772)

Mainly because it was causing crash on Windows with error "unlock of unowned mutex".
---
 blockchain-explorer/blockchain-explorer.cpp | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/blockchain-explorer/blockchain-explorer.cpp b/blockchain-explorer/blockchain-explorer.cpp
index 035b84ea..3e7d9a97 100644
--- a/blockchain-explorer/blockchain-explorer.cpp
+++ b/blockchain-explorer/blockchain-explorer.cpp
@@ -103,23 +103,24 @@ class HttpQueryRunner {
         Self->finish(nullptr);
       }
     });
-    mutex_.lock();
     scheduler_ptr->run_in_context_external([&]() { func(std::move(P)); });
   }
   void finish(MHD_Response* response) {
+    std::unique_lock<std::mutex> lock(mutex_);
     response_ = response;
-    mutex_.unlock();
+    cond.notify_all();
   }
   MHD_Response* wait() {
-    mutex_.lock();
-    mutex_.unlock();
+    std::unique_lock<std::mutex> lock(mutex_);
+    cond.wait(lock, [&]() { return response_ != nullptr; });
     return response_;
   }
 
  private:
   std::function<void(td::Promise<MHD_Response*>)> func_;
-  MHD_Response* response_;
+  MHD_Response* response_ = nullptr;
   std::mutex mutex_;
+  std::condition_variable cond;
 };
 
 class CoreActor : public CoreActorInterface {