From a6f4cb164752ce5dbafcd3900e7f46df938d654a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9o=20Lam?= <leo@innovatetechnologi.es>
Date: Thu, 13 Jun 2019 23:34:25 +0200
Subject: [PATCH] DiscordHandler: Don't delay shutdown by up to 2s

Currently, it is possible for the DiscordHandler thread to be in the
middle of sleeping when Dolphin is closing. This results in a very
noticeable delay of up to 2 seconds that is unacceptable, especially
for people who don't use the Discord integration.

This fixes the issue by making the thread wait on an Event instead
and signalling it when shutting down.
---
 Source/Core/DolphinQt/DiscordHandler.cpp | 14 ++++++++------
 Source/Core/DolphinQt/DiscordHandler.h   |  2 ++
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/Source/Core/DolphinQt/DiscordHandler.cpp b/Source/Core/DolphinQt/DiscordHandler.cpp
index 8bfadd21dd..ee90692b35 100644
--- a/Source/Core/DolphinQt/DiscordHandler.cpp
+++ b/Source/Core/DolphinQt/DiscordHandler.cpp
@@ -6,6 +6,7 @@
 
 #include "DolphinQt/DiscordHandler.h"
 
+#include <chrono>
 #include <iterator>
 
 #include <QApplication>
@@ -35,10 +36,12 @@ void DiscordHandler::Start()
 
 void DiscordHandler::Stop()
 {
-  m_stop_requested.Set(true);
+  if (!m_thread.joinable())
+    return;
 
-  if (m_thread.joinable())
-    m_thread.join();
+  m_stop_requested.Set(true);
+  m_wakeup_event.Set();
+  m_thread.join();
 }
 
 void DiscordHandler::DiscordJoinRequest(const char* id, const std::string& discord_tag,
@@ -68,8 +71,7 @@ void DiscordHandler::Run()
 {
   while (!m_stop_requested.IsSet())
   {
-    if (m_thread.joinable())
-      Discord::CallPendingCallbacks();
+    Discord::CallPendingCallbacks();
 
     // close and remove dead requests
     {
@@ -91,7 +93,7 @@ void DiscordHandler::Run()
       }
     }
 
-    Common::SleepCurrentThread(1000 * 2);
+    m_wakeup_event.WaitFor(std::chrono::seconds{2});
   }
 }
 
diff --git a/Source/Core/DolphinQt/DiscordHandler.h b/Source/Core/DolphinQt/DiscordHandler.h
index d1be3d01c0..109e5b1a91 100644
--- a/Source/Core/DolphinQt/DiscordHandler.h
+++ b/Source/Core/DolphinQt/DiscordHandler.h
@@ -10,6 +10,7 @@
 
 #include <QObject>
 
+#include "Common/Event.h"
 #include "Common/Flag.h"
 
 #include "UICommon/DiscordPresence.h"
@@ -42,6 +43,7 @@ private:
   void Run();
   QWidget* m_parent;
   Common::Flag m_stop_requested;
+  Common::Event m_wakeup_event;
   std::thread m_thread;
   std::list<DiscordJoinRequestDialog> m_request_dialogs;
   std::mutex m_request_dialogs_mutex;