From 84737941e14adc03efa57d184279b3df1f49405e Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Thu, 22 Jan 2004 10:42:32 +0000
Subject: [PATCH] Added controls over the datatbase pager threading priority
 during and outwith the frame.

---
 include/osgDB/DatabasePager | 16 ++++++++++++++++
 src/osgDB/DatabasePager.cpp | 15 +++++++++++++--
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/include/osgDB/DatabasePager b/include/osgDB/DatabasePager
index 1971523b2..14f244848 100644
--- a/include/osgDB/DatabasePager
+++ b/include/osgDB/DatabasePager
@@ -98,6 +98,19 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
         /** Get the whether UseFrameBlock is on or off.*/
         bool getUseFrameBlock() const { return _useFrameBlock; }
         
+
+        /** Set the priority of the database pager thread during the frame (i.e. while cull and draw are running.)*/
+        void setThreadPriorityDuringFrame(ThreadPriority duringFrame) { _threadPriorityDuringFrame = duringFrame; }
+
+        /** Get the priority of the database pager thread during the frame*/
+        ThreadPriority getThreadPriorityDuringFrame() const { return _threadPriorityDuringFrame; }
+        
+        /** Set the priority of the database pager thread when the frame is not being exectuted (i.e. before or after cull and draw have run.)*/
+        void setThreadPriorityOutwithFrame(ThreadPriority outwithFrame)  { _threadPriorityOutwithFrame = outwithFrame; }
+
+        /** Get the priority of the database pager thread when the frame is not being exectuted.*/
+        ThreadPriority getThreadPriorityOutwithFrame() const { return _threadPriorityOutwithFrame; }
+        
         
         /** Signal the database thread that the update, cull and draw has begun for a new frame.
           * Note, this is called by the application so that the database pager can go to sleep while the CPU is busy on the main rendering threads. */
@@ -214,6 +227,9 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
         osg::ref_ptr<Block>             _frameBlock;
         int                             _frameNumber;
 
+        ThreadPriority                  _threadPriorityDuringFrame;
+        ThreadPriority                  _threadPriorityOutwithFrame;
+
         DatabaseRequestList             _fileRequestList;
         OpenThreads::Mutex              _fileRequestListMutex;
         osg::ref_ptr<Block>             _fileRequestListEmptyBlock;
diff --git a/src/osgDB/DatabasePager.cpp b/src/osgDB/DatabasePager.cpp
index 5d7683d79..d2dbd5a6b 100644
--- a/src/osgDB/DatabasePager.cpp
+++ b/src/osgDB/DatabasePager.cpp
@@ -19,11 +19,14 @@ DatabasePager::DatabasePager()
 {
     //osg::notify(osg::INFO)<<"Constructing DatabasePager()"<<std::endl;
     
-    _useFrameBlock = false;    
+    _useFrameBlock = false;
     _frameNumber = 0;
     _frameBlock = new Block;
     _fileRequestListEmptyBlock = new Block;
 
+    _threadPriorityDuringFrame = PRIORITY_MIN;
+    _threadPriorityOutwithFrame = PRIORITY_NOMINAL;
+
     _deleteRemovedSubgraphsInDatabaseThread = true;
     
     _expiryDelay = 1.0;
@@ -166,7 +169,7 @@ void DatabasePager::requestNodeFile(const std::string& fileName,osg::Group* grou
         {
             s_startThreadCalled = true;
             osg::notify(osg::DEBUG_INFO)<<"DatabasePager::startThread()"<<std::endl;
-            setSchedulePriority(PRIORITY_MIN);
+            setSchedulePriority(_threadPriorityDuringFrame);
             startThread();
         }
                 
@@ -182,12 +185,20 @@ void DatabasePager::signalBeginFrame(const osg::FrameStamp* framestamp)
     } //else osg::notify(osg::INFO) << "signalBeginFrame >>>>>>>>>>>>>>>>"<<std::endl;
 
     _frameBlock->reset();
+
+    if (_threadPriorityDuringFrame!=getSchedulePriority())
+        setSchedulePriority(_threadPriorityDuringFrame);
+
 }
 
 void DatabasePager::signalEndFrame()
 {
     //osg::notify(osg::INFO) << "signalEndFrame <<<<<<<<<<<<<<<<<<<< "<<std::endl;
     _frameBlock->release();
+
+    if (_threadPriorityOutwithFrame!=getSchedulePriority())
+        setSchedulePriority(_threadPriorityOutwithFrame);
+
 }
 
 class FindCompileableGLObjectsVisitor : public osg::NodeVisitor