From 78fd5b78da41417b9293b197ff059d5a7a0187df Mon Sep 17 00:00:00 2001
From: Alexander Bock <mail@alexanderbock.eu>
Date: Tue, 22 Feb 2022 23:24:37 +0100
Subject: [PATCH] Wait for initialization when adding assets at runtime. 
 Correctly destroy the RenderableGalaxy shader when deinitializing (closes
 #1601)

---
 include/openspace/util/threadpool.h           | 2 ++
 modules/galaxy/rendering/renderablegalaxy.cpp | 5 +++++
 src/scene/sceneinitializer.cpp                | 7 +++++++
 src/util/threadpool.cpp                       | 4 ++++
 4 files changed, 18 insertions(+)

diff --git a/include/openspace/util/threadpool.h b/include/openspace/util/threadpool.h
index 73a65e5302..6c2287f258 100644
--- a/include/openspace/util/threadpool.h
+++ b/include/openspace/util/threadpool.h
@@ -56,6 +56,8 @@ public:
     void enqueue(std::function<void()> f);
     void clearTasks();
 
+    bool hasOutstandingTasks() const;
+
 private:
     friend class Worker;
 
diff --git a/modules/galaxy/rendering/renderablegalaxy.cpp b/modules/galaxy/rendering/renderablegalaxy.cpp
index ead0306bcb..891270155b 100644
--- a/modules/galaxy/rendering/renderablegalaxy.cpp
+++ b/modules/galaxy/rendering/renderablegalaxy.cpp
@@ -494,6 +494,11 @@ void RenderableGalaxy::deinitializeGL() {
         _raycaster = nullptr;
     }
 
+    global::renderEngine->removeRenderProgram(_pointsProgram.get());
+    _pointsProgram = nullptr;
+    global::renderEngine->removeRenderProgram(_billboardsProgram.get());
+    _billboardsProgram = nullptr;
+
     glDeleteVertexArrays(1, &_pointsVao);
     glDeleteBuffers(1, &_positionVbo);
     glDeleteBuffers(1, &_colorVbo);
diff --git a/src/scene/sceneinitializer.cpp b/src/scene/sceneinitializer.cpp
index 2f121cf403..b1068e27a9 100644
--- a/src/scene/sceneinitializer.cpp
+++ b/src/scene/sceneinitializer.cpp
@@ -100,6 +100,13 @@ void MultiThreadedSceneInitializer::initializeNode(SceneGraphNode* node) {
 }
 
 std::vector<SceneGraphNode*> MultiThreadedSceneInitializer::takeInitializedNodes() {
+    // Some of the scene graph nodes might still be in the initialization queue and we
+    // should wait for those to finish or we end up in some half-initialized state since
+    // other parts of the application already know about their existence
+    while (_threadPool.hasOutstandingTasks()) {
+        std::this_thread::sleep_for(std::chrono::milliseconds(1));
+    }
+
     std::lock_guard g(_mutex);
     std::vector<SceneGraphNode*> nodes = std::move(_initializedNodes);
     return nodes;
diff --git a/src/util/threadpool.cpp b/src/util/threadpool.cpp
index b07c2b44a2..ab77e0939c 100644
--- a/src/util/threadpool.cpp
+++ b/src/util/threadpool.cpp
@@ -99,4 +99,8 @@ void ThreadPool::clearTasks() {
     } // release lock
 }
 
+bool ThreadPool::hasOutstandingTasks() const {
+    return !tasks.empty();
+}
+
 } // namespace openspace