From 28895baa88d083994a817f27a91a07f9f308a7c3 Mon Sep 17 00:00:00 2001
From: Anton Tarasenko <dkanus@gmail.com>
Date: Sun, 17 Jul 2022 02:30:19 +0700
Subject: [PATCH] Refactor shutting down process

---
 .../AcediaEnvironment/AcediaEnvironment.uc    | 88 ++++++++++++++++---
 sources/BaseRealm/Global.uc                   |  1 +
 .../ServerRealm/API/Unreal/ServerUnrealAPI.uc | 16 ++++
 3 files changed, 92 insertions(+), 13 deletions(-)

diff --git a/sources/BaseRealm/AcediaEnvironment/AcediaEnvironment.uc b/sources/BaseRealm/AcediaEnvironment/AcediaEnvironment.uc
index 0067cc9..4a0269b 100644
--- a/sources/BaseRealm/AcediaEnvironment/AcediaEnvironment.uc
+++ b/sources/BaseRealm/AcediaEnvironment/AcediaEnvironment.uc
@@ -44,6 +44,8 @@ class AcediaEnvironment extends AcediaObject;
  *  considered enabled at the same time.
  */
 
+var private bool acediaShutDown;
+
 var private array< class<_manifest> > availablePackages;
 var private array< class<_manifest> > loadedPackages;
 
@@ -58,9 +60,62 @@ var private LoggerAPI.Definition errNotRegistered, errFeatureAlreadyEnabled;
 var private LoggerAPI.Definition warnFeatureAlreadyEnabled;
 var private LoggerAPI.Definition errFeatureClassAlreadyEnabled;
 
+var private SimpleSignal                        onShutdownSignal;
+var private SimpleSignal                        onShutdownSystemSignal;
 var private Environment_FeatureEnabled_Signal   onFeatureEnabledSignal;
 var private Environment_FeatureDisabled_Signal  onFeatureDisabledSignal;
 
+protected function Constructor()
+{
+    //  Always register our core package
+    RegisterPackage_S("AcediaCore");
+    onShutdownSignal = SimpleSignal(
+        _.memory.Allocate(class'SimpleSignal'));
+    onShutdownSystemSignal = SimpleSignal(
+        _.memory.Allocate(class'SimpleSignal'));
+    onFeatureEnabledSignal = Environment_FeatureEnabled_Signal(
+        _.memory.Allocate(class'Environment_FeatureEnabled_Signal'));
+    onFeatureDisabledSignal = Environment_FeatureDisabled_Signal(
+        _.memory.Allocate(class'Environment_FeatureDisabled_Signal'));
+}
+
+protected function Finalizer()
+{
+    _.memory.Free(onShutdownSignal);
+    _.memory.Free(onShutdownSystemSignal);
+    _.memory.Free(onFeatureEnabledSignal);
+    _.memory.Free(onFeatureDisabledSignal);
+}
+
+/**
+ *  Signal that will be emitted before Acedia shuts down.
+ *  At this point all APIs should still exist and function.
+ *
+ *  [Signature]
+ *  void <slot>()
+ */
+/* SIGNAL */
+public final function SimpleSlot OnShutDown(AcediaObject receiver)
+{
+    return SimpleSlot(onShutdownSignal.NewSlot(receiver));
+}
+
+/**
+ *  Signal that will be emitted during Acedia shut down. System API use it to
+ *  clean up after themselves, so one shouldn't rely on them.
+ *
+ *  There is no reason to use this signal unless you're reimplementing one of
+ *  the APIs. Otherwise you probably want to use `OnShutDown()` signal instead.
+ *
+ *  [Signature]
+ *  void <slot>()
+ */
+/* SIGNAL */
+public final function SimpleSlot OnShutDownSystem(AcediaObject receiver)
+{
+    return SimpleSlot(onShutdownSystemSignal.NewSlot(receiver));
+}
+
 /**
  *  Signal that will be emitted when new `Feature` is enabled.
  *  Emitted after `Feature`'s `OnEnabled()` method was called.
@@ -96,20 +151,27 @@ public final function Environment_FeatureDisabled_Slot OnFeatureDisabled(
         onFeatureEnabledSignal.NewSlot(receiver));
 }
 
-protected function Constructor()
-{
-    //  Always register our core package
-    RegisterPackage_S("AcediaCore");
-    onFeatureEnabledSignal = Environment_FeatureEnabled_Signal(
-        _.memory.Allocate(class'Environment_FeatureEnabled_Signal'));
-    onFeatureDisabledSignal = Environment_FeatureDisabled_Signal(
-        _.memory.Allocate(class'Environment_FeatureDisabled_Signal'));
-}
-
-protected function Finalizer()
+/**
+ *  Shuts AcediaCore down, performing all the necessary cleaning up.
+ */
+public final function Shutdown()
 {
-    _.memory.Free(onFeatureEnabledSignal);
-    _.memory.Free(onFeatureDisabledSignal);
+    local LevelCore core;
+    if (acediaShutDown) {
+        return;
+    }
+    DisableAllFeatures();
+    onShutdownSignal.Emit();
+    onShutdownSystemSignal.Emit();
+    core = class'ServerLevelCore'.static.GetInstance();
+    if (core != none) {
+        core.Destroy();
+    }
+    core = class'ClientLevelCore'.static.GetInstance();
+    if (core != none) {
+        core.Destroy();
+    }
+    acediaShutDown = true;
 }
 
 /**
diff --git a/sources/BaseRealm/Global.uc b/sources/BaseRealm/Global.uc
index e22e4c6..26b5e5b 100644
--- a/sources/BaseRealm/Global.uc
+++ b/sources/BaseRealm/Global.uc
@@ -59,6 +59,7 @@ protected function Initialize()
     //  Special case that we cannot spawn with memory API since it obviously
     //  does not exist yet!
     memory      = new class'MemoryAPI';
+    memory._constructor();
     //  `TextAPI` and `CollectionsAPI` need to be loaded before `LoggerAPI`
     ref         = RefAPI(memory.Allocate(class'RefAPI'));
     box         = BoxAPI(memory.Allocate(class'BoxAPI'));
diff --git a/sources/ServerRealm/API/Unreal/ServerUnrealAPI.uc b/sources/ServerRealm/API/Unreal/ServerUnrealAPI.uc
index 61bf0c2..2fb8889 100644
--- a/sources/ServerRealm/API/Unreal/ServerUnrealAPI.uc
+++ b/sources/ServerRealm/API/Unreal/ServerUnrealAPI.uc
@@ -21,6 +21,22 @@ class ServerUnrealAPI extends ServerUnrealAPIBase;
 
 var private LoggerAPI.Definition fatalNoStalker;
 
+protected function Constructor()
+{
+    _.environment.OnShutDownSystem(self).connect = HandleShutdown;
+}
+
+protected function HandleShutdown()
+{
+    local UnrealService service;
+
+    service = UnrealService(class'UnrealService'.static.GetInstance());
+    //  This has to clean up anything we've added
+    if (service != none) {
+        service.Destroy();
+    }
+}
+
 /* SIGNAL */
 public function Unreal_OnTick_Slot OnTick(
     AcediaObject receiver)