From 6a66d74e19f4397f6a9371a1d0a5005ddd4320c5 Mon Sep 17 00:00:00 2001
From: Brad Davis <bdavis@saintandreas.org>
Date: Mon, 8 Feb 2016 23:45:04 -0800
Subject: [PATCH] Limit the number of concurrent file parsing threads

---
 interface/src/Application.cpp | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index ef0c2a588e..efc482a3b4 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -12,13 +12,13 @@
 #include "Application.h"
 
 #include <gl/Config.h>
-
 #include <glm/glm.hpp>
 #include <glm/gtx/component_wise.hpp>
 #include <glm/gtx/quaternion.hpp>
 #include <glm/gtx/vector_angle.hpp>
 #include <glm/gtc/type_ptr.hpp>
 
+#include <Qt>
 #include <QtCore/QDebug>
 #include <QtCore/QJsonDocument>
 #include <QtCore/QJsonObject>
@@ -27,6 +27,7 @@
 #include <QtCore/QTimer>
 #include <QtCore/QAbstractNativeEventFilter>
 #include <QtCore/QMimeData>
+#include <QtCore/QThreadPool>
 
 #include <QtGui/QScreen>
 #include <QtGui/QImage>
@@ -419,6 +420,14 @@ Application::Application(int& argc, char** argv, QElapsedTimer& startupTimer) :
     _maxOctreePPS(maxOctreePacketsPerSecond.get()),
     _lastFaceTrackerUpdate(0)
 {
+    // FIXME this may be excessivly conservative.  On the other hand 
+    // maybe I'm used to having an 8-core machine
+    // Perhaps find the ideal thread count  and subtract 2 or 3 
+    // (main thread, present thread, random OS load)
+    // More threads == faster concurrent loads, but also more concurrent 
+    // load on the GPU until we can serialize GPU transfers (off the main thread)
+    QThreadPool::globalInstance()->setMaxThreadCount(2);
+    thread()->setPriority(QThread::HighPriority);
     thread()->setObjectName("Main Thread");
 
     setInstance(this);
@@ -1287,6 +1296,9 @@ void Application::initializeUi() {
 }
 
 void Application::paintGL() {
+
+
+
     // paintGL uses a queued connection, so we can get messages from the queue even after we've quit
     // and the plugins have shutdown
     if (_aboutToQuit) {
@@ -4762,8 +4774,11 @@ void Application::updateDisplayMode() {
         foreach(auto displayPlugin, standard) {
             addDisplayPluginToMenu(displayPlugin, first);
             // This must be a queued connection to avoid a deadlock
-            QObject::connect(displayPlugin.get(), &DisplayPlugin::requestRender,
-                this, &Application::paintGL, Qt::QueuedConnection);
+            QObject::connect(displayPlugin.get(), &DisplayPlugin::requestRender, [=] {
+                postEvent(this, new LambdaEvent([=] {
+                    paintGL(); 
+                }), Qt::HighEventPriority);
+            });
 
             QObject::connect(displayPlugin.get(), &DisplayPlugin::recommendedFramebufferSizeChanged, [this](const QSize & size) {
                 resizeGL();