From ff862a2f206aa2449e4c7ee77d2914b091103086 Mon Sep 17 00:00:00 2001
From: Gene Walters <genewalt@amazon.com>
Date: Mon, 22 Nov 2021 18:56:48 -0800
Subject: [PATCH] Fix memory leak of ProcessWatcher

Signed-off-by: Gene Walters <genewalt@amazon.com>
---
 .../Editor/MultiplayerEditorSystemComponent.cpp     | 13 +++++++++----
 .../Editor/MultiplayerEditorSystemComponent.h       |  6 ++++--
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/Gems/Multiplayer/Code/Source/Editor/MultiplayerEditorSystemComponent.cpp b/Gems/Multiplayer/Code/Source/Editor/MultiplayerEditorSystemComponent.cpp
index 669393e31e..7cc6fbc1b5 100644
--- a/Gems/Multiplayer/Code/Source/Editor/MultiplayerEditorSystemComponent.cpp
+++ b/Gems/Multiplayer/Code/Source/Editor/MultiplayerEditorSystemComponent.cpp
@@ -193,7 +193,7 @@ namespace Multiplayer
         }
     }
 
-    AzFramework::ProcessWatcher* LaunchEditorServer()
+    void MultiplayerEditorSystemComponent::LaunchEditorServer()
     {
         // Assemble the server's path
         AZ::CVarFixedString serverProcess = editorsv_process;
@@ -248,7 +248,13 @@ namespace Multiplayer
             "MultiplayerEditor", processLaunchInfo.m_launchResult != AzFramework::ProcessLauncher::ProcessLaunchResult::PLR_MissingFile,
             "LaunchEditorServer failed! The ServerLauncher binary is missing! (%s)  Please build server launcher.", serverPath.c_str())
 
-        return outProcess;
+        // Stop the previous server if one exists
+        if (m_serverProcessWatcher)
+        {
+            m_serverProcessWatcher->TerminateProcess(0);
+        }
+        m_serverProcessWatcher.reset(outProcess);
+        m_serverProcessTracePrinter = AZStd::make_unique<ProcessCommunicatorTracePrinter>(m_serverProcessWatcher->GetCommunicator(), "EditorServer");
     }
 
     void MultiplayerEditorSystemComponent::OnGameEntitiesStarted()
@@ -308,8 +314,7 @@ namespace Multiplayer
             editorNetworkInterface->Listen(editorsv_port);
 
             // Launch the editor-server
-            m_serverProcessWatcher = LaunchEditorServer();
-            m_serverProcessTracePrinter = AZStd::make_unique<ProcessCommunicatorTracePrinter>(m_serverProcessWatcher->GetCommunicator(), "EditorServer");
+            LaunchEditorServer();
             AZ::TickBus::Handler::BusConnect();
         }
         else
diff --git a/Gems/Multiplayer/Code/Source/Editor/MultiplayerEditorSystemComponent.h b/Gems/Multiplayer/Code/Source/Editor/MultiplayerEditorSystemComponent.h
index 330a2c9d81..5e49f8f08d 100644
--- a/Gems/Multiplayer/Code/Source/Editor/MultiplayerEditorSystemComponent.h
+++ b/Gems/Multiplayer/Code/Source/Editor/MultiplayerEditorSystemComponent.h
@@ -83,7 +83,9 @@ namespace Multiplayer
         bool IsInGameMode() override;
         //! @}
 
-    private:    
+    private:
+        void LaunchEditorServer();
+        
         //! EditorEvents::Handler overrides
         //! @{
         void OnEditorNotifyEvent(EEditorNotifyEvent event) override;
@@ -106,7 +108,7 @@ namespace Multiplayer
         //! @}
 
         IEditor* m_editor = nullptr;
-        AzFramework::ProcessWatcher* m_serverProcessWatcher = nullptr;
+        AZStd::unique_ptr<AzFramework::ProcessWatcher> m_serverProcessWatcher = nullptr;
         AZStd::unique_ptr<ProcessCommunicatorTracePrinter> m_serverProcessTracePrinter = nullptr;
         AzNetworking::ConnectionId m_editorConnId;