From bf320e4826ece33b0190332dda3e135786b48c89 Mon Sep 17 00:00:00 2001
From: Tim Ledbetter <timledbetter@gmail.com>
Date: Sat, 1 Apr 2023 23:23:43 +0100
Subject: [PATCH] Chess: Send a quit command to ChessEngine when it is no
 longer in use

The chess GUI now instructs the ChessEngine to gracefully exit by
sending a UCI quit command.
---
 Userland/Games/Chess/Engine.cpp | 8 ++++++--
 Userland/Games/Chess/Engine.h   | 3 ++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/Userland/Games/Chess/Engine.cpp b/Userland/Games/Chess/Engine.cpp
index a28b5fc13c..cbfcf40d1d 100644
--- a/Userland/Games/Chess/Engine.cpp
+++ b/Userland/Games/Chess/Engine.cpp
@@ -13,8 +13,7 @@
 
 Engine::~Engine()
 {
-    if (m_pid != -1)
-        kill(m_pid, SIGINT);
+    quit();
 }
 
 Engine::Engine(StringView command)
@@ -66,3 +65,8 @@ void Engine::handle_bestmove(Chess::UCI::BestMoveCommand const& command)
 
     m_bestmove_callback = nullptr;
 }
+
+void Engine::quit()
+{
+    send_command(Chess::UCI::QuitCommand());
+}
diff --git a/Userland/Games/Chess/Engine.h b/Userland/Games/Chess/Engine.h
index d91127714b..dd5906cf84 100644
--- a/Userland/Games/Chess/Engine.h
+++ b/Userland/Games/Chess/Engine.h
@@ -33,6 +33,7 @@ public:
     }
 
 private:
+    void quit();
+
     Function<void(Chess::Move)> m_bestmove_callback;
-    pid_t m_pid { -1 };
 };