From 5577b5a6a83c57fac2a88a9ba8e107f1ba8674ee Mon Sep 17 00:00:00 2001
From: zetaPRIME <qmanxt@gmail.com>
Date: Wed, 3 May 2017 04:19:30 -0400
Subject: [PATCH] threads now end cleanly, and do so on exit

---
 libstarlight/source/starlight/Application.cpp | 12 ++++++++--
 .../source/starlight/threading/Thread.cpp     | 23 ++++++++++++++++++-
 .../source/starlight/threading/Thread.h       |  2 ++
 libstarlight/todo.txt                         |  3 ++-
 4 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/libstarlight/source/starlight/Application.cpp b/libstarlight/source/starlight/Application.cpp
index edeed83..506b9de 100644
--- a/libstarlight/source/starlight/Application.cpp
+++ b/libstarlight/source/starlight/Application.cpp
@@ -17,6 +17,9 @@ using starlight::ThemeManager;
 using starlight::InputManager;
 using starlight::gfx::RenderCore;
 
+using starlight::threading::Thread;
+using starlight::threading::ThreadState;
+
 using starlight::ui::TouchScreenCanvas;
 using starlight::ui::TopScreenCanvas;
 
@@ -83,6 +86,9 @@ void Application::_init() {
 void Application::_end() {
     End();
     
+    for (auto& thread : threads) thread->Exit();
+    threads.clear();
+    
     //for (auto& f : forms) f->Close();
     forms.clear(); // not sure why, but not doing this results in a data abort if any forms are active
     
@@ -159,8 +165,10 @@ void Application::_mainLoop() {
     RenderCore::EndFrame();
     
     while (!threads.empty() && frameTimer.GetSubframe() < 0.9) {
-        threads.front()->Resume();
-        if (threads.size() > 1) threads.splice(threads.end(), threads, threads.begin()); // move to back of queue
+        auto thread = threads.front();
+        thread->Resume();
+        if (thread->state != ThreadState::Finished) threads.splice(threads.end(), threads, threads.begin()); // move to back of queue
+        else threads.pop_front(); // or just discard if already exited
     }
 }
 
diff --git a/libstarlight/source/starlight/threading/Thread.cpp b/libstarlight/source/starlight/threading/Thread.cpp
index 66adf77..cb40c04 100644
--- a/libstarlight/source/starlight/threading/Thread.cpp
+++ b/libstarlight/source/starlight/threading/Thread.cpp
@@ -37,6 +37,9 @@ void Thread::_FinishStart() {
     state = ThreadState::Running;
     Yield();
     Body();
+    state = ThreadState::Finished;
+    OnExit();
+    threadExit(0);
 }
 
 void Thread::Yield() {
@@ -45,12 +48,30 @@ void Thread::Yield() {
     svcWaitSynchronization(event, -1 /*U64_MAX*/);
     //svcWaitSynchronization(event, 65536);
 	svcClearEvent(event);
+    if (state == ThreadState::Finished && OnExit()) {
+        threadExit(0);
+    }
     state = ThreadState::Running;
 }
 
+void Thread::Exit() {
+    if (state == ThreadState::Idle) { // exited from outside
+        state = ThreadState::Finished;
+        Resume();
+        threadJoin(static_cast<SysThread>(sthread), -1);
+    } else if (state == ThreadState::Running) { // exited self
+        state = ThreadState::Finished;
+        OnExit();
+        threadExit(0);
+    }
+    
+}
+
 void Thread::Resume() {
-    if (state != ThreadState::Idle) return; // not applicable
+    if (state != ThreadState::Idle && state != ThreadState::Finished) return; // not applicable
     svcSignalEvent(event);
 }
 
+bool Thread::OnExit() { return true; } // default to "trivial" (no cleanup necessary)
+
 //
diff --git a/libstarlight/source/starlight/threading/Thread.h b/libstarlight/source/starlight/threading/Thread.h
index c950767..3fc6fc4 100644
--- a/libstarlight/source/starlight/threading/Thread.h
+++ b/libstarlight/source/starlight/threading/Thread.h
@@ -30,8 +30,10 @@ namespace starlight {
             void Enqueue();
             void Yield();
             void Resume();
+            void Exit();
             
             virtual void Body() = 0;
+            virtual bool OnExit();
         };
     }
 }
diff --git a/libstarlight/todo.txt b/libstarlight/todo.txt
index 402423a..50746aa 100644
--- a/libstarlight/todo.txt
+++ b/libstarlight/todo.txt
@@ -25,7 +25,8 @@ roadmap to v0.5.1 {
         ...and some mechanism for allowing it to opt out of the rest of the cycle
         
         Trackable sideclass for threads; float progress 0..1, etc.
-        MAKE THREADS END CLEANLY
+        - MAKE THREADS END CLEANLY
+        ^ observed a single instance of being stalled on redscreen, not really sure what that was about
     }
 } then by v0.5.5 {
     event propagation system of some sort; threadsafe to whatever extent is needed on 3DS