Better closing of the loop

src/Storages/RabbitMQ/RabbitMQConnection.cpp

@@ -122,4 +122,23 @@ void RabbitMQConnection::disconnectImpl(bool immediately)
         event_handler.iterateLoop();
 }
 
+RabbitMQConnection::~RabbitMQConnection()
+{
+    std::lock_guard lock(mutex);
+
+    if (!connection)
+        return;
+
+    try
+    {
+        /// Try to always close the connection gracefully (run the loop to see the closing callbacks)
+        /// to make sure that the associated callbacks and pending events are removed.
+        disconnectImpl();
+    }
+    catch (...)
+    {
+        tryLogCurrentException(__PRETTY_FUNCTION__);
+    }
+}
+
 }

src/Storages/RabbitMQ/RabbitMQConnection.h

@@ -24,6 +24,8 @@ class RabbitMQConnection
 public:
     RabbitMQConnection(const RabbitMQConfiguration & configuration_, Poco::Logger * log_);
 
+    ~RabbitMQConnection();
+
     bool isConnected();
 
     bool connect();

src/Storages/UVLoop.h

@@ -6,6 +6,7 @@
 #include <boost/noncopyable.hpp>
 
 #include <Common/Exception.h>
+#include <Common/logger_useful.h>
 
 namespace DB
 {
@@ -30,7 +31,38 @@ public:
     ~UVLoop()
     {
         if (loop_ptr)
-            uv_loop_close(loop_ptr.get());
+        {
+            auto res = uv_loop_close(loop_ptr.get());
+
+            if (res == UV_EBUSY)
+            {
+                LOG_DEBUG(log, "Closing pending handles");
+                uv_walk(loop_ptr.get(), [](uv_handle_t * handle, void *)
+                {
+                    if (!uv_is_closing(handle))
+                        uv_close(handle, [](uv_handle_t *){});
+                }, nullptr);
+
+                /// Run the loop until there are no pending callbacks.
+                while (true)
+                {
+                    res = uv_run(loop_ptr.get(), UV_RUN_ONCE);
+                    if (res)
+                        LOG_DEBUG(log, "Waiting for pending callbacks to finish ({})", res);
+                    else
+                        break;
+                }
+
+                res = uv_loop_close(loop_ptr.get());
+                if (res == UV_EBUSY)
+                {
+                    LOG_ERROR(
+                        log, "Failed to close libuv loop (active requests/handles in the loop: {})",
+                        uv_loop_alive(loop_ptr.get()));
+                    chassert(false);
+                }
+            }
+        }
     }
 
     inline uv_loop_t * getLoop() { return loop_ptr.get(); }
@@ -39,6 +71,7 @@ public:
 
 private:
     std::unique_ptr<uv_loop_t> loop_ptr;
+    Poco::Logger * log = &Poco::Logger::get("UVLoop");
 };
 
 }