ViewerBase::ThreadingModel ViewerBase::suggestBestThreadingModel()
{
const char* str = getenv("OSG_THREADING");
if (str)
{
if (strcmp(str,"SingleThreaded")==0) return SingleThreaded;
else if (strcmp(str,"CullDrawThreadPerContext")==0) return CullDrawThreadPerContext;
else if (strcmp(str,"DrawThreadPerContext")==0) return DrawThreadPerContext;
else if (strcmp(str,"CullThreadPerCameraDrawThreadPerContext")==0) return CullThreadPerCameraDrawThreadPerContext;
}
Contexts contexts;
getContexts(contexts);
if (contexts.empty()) return SingleThreaded;
#if 0
// temporary hack to disable multi-threading under Windows till we find good solutions for
// crashes that users are seeing.
return SingleThreaded;
#endif
Cameras cameras;
getCameras(cameras);
if (cameras.empty()) return SingleThreaded;
int numProcessors = OpenThreads::GetNumberOfProcessors();
if (contexts.size()==1)
{
if (numProcessors==1) return SingleThreaded;
else return DrawThreadPerContext;
}
#if 1
if (numProcessors >= static_cast<int>(cameras.size()+contexts.size()))
{
return CullThreadPerCameraDrawThreadPerContext;
}
#endif
return DrawThreadPerContext;
}
void ViewerBase::startThreading()
{
if (_threadsRunning) return;
OSG_INFO<<"Viewer::startThreading() - starting threading"<<std::endl;
// release any context held by the main thread.
releaseContext();
_threadingModel = _threadingModel==AutomaticSelection ? suggestBestThreadingModel() : _threadingModel;
Contexts contexts;
getContexts(contexts);
OSG_INFO<<"Viewer::startThreading() - contexts.size()="<<contexts.size()<<std::endl;
Cameras cameras;
getCameras(cameras);
unsigned int numThreadsOnStartBarrier = 0;
unsigned int numThreadsOnEndBarrier = 0;
switch(_threadingModel)
{
case(SingleThreaded):
numThreadsOnStartBarrier = 1;
numThreadsOnEndBarrier = 1;
return;
case(CullDrawThreadPerContext):
numThreadsOnStartBarrier = contexts.size()+1;
numThreadsOnEndBarrier = contexts.size()+1;
break;
case(DrawThreadPerContext):
numThreadsOnStartBarrier = 1;
numThreadsOnEndBarrier = 1;
break;
case(CullThreadPerCameraDrawThreadPerContext):
numThreadsOnStartBarrier = cameras.size()+1;
numThreadsOnEndBarrier = 1;
break;
default:
OSG_NOTICE<<"Error: Threading model not selected"<<std::endl;
return;
}
// using multi-threading so make sure that new objects are allocated with thread safe ref/unref
osg::Referenced::setThreadSafeReferenceCounting(true);
Scenes scenes;
getScenes(scenes);
for(Scenes::iterator scitr = scenes.begin();
scitr != scenes.end();
++scitr)
{
if ((*scitr)->getSceneData())
{
OSG_INFO<<"Making scene thread safe"<<std::endl;
// make sure that existing scene graph objects are allocated with thread safe ref/unref
(*scitr)->getSceneData()->setThreadSafeRefUnref(true);
// update the scene graph so that it has enough GL object buffer memory for the graphics contexts that will be using it.
(*scitr)->getSceneData()->resizeGLObjectBuffers(osg::DisplaySettings::instance()->getMaxNumberOfGraphicsContexts());
}
}
int numProcessors = OpenThreads::GetNumberOfProcessors();
bool affinity = numProcessors>1;
Contexts::iterator citr;
unsigned int numViewerDoubleBufferedRenderingOperation = 0;
bool graphicsThreadsDoesCull = _threadingModel == CullDrawThreadPerContext || _threadingModel==SingleThreaded;
for(Cameras::iterator camItr = cameras.begin();
camItr != cameras.end();
++camItr)
{
osg::Camera* camera = *camItr;
Renderer* renderer = dynamic_cast<Renderer*>(camera->getRenderer());
if (renderer)
{
renderer->setGraphicsThreadDoesCull(graphicsThreadsDoesCull);
renderer->setDone(false);
renderer->reset();
++numViewerDoubleBufferedRenderingOperation;
}
}
if (_threadingModel==CullDrawThreadPerContext)
{
_startRenderingBarrier = 0;
_endRenderingDispatchBarrier = 0;
_endDynamicDrawBlock = 0;
}
else if (_threadingModel==DrawThreadPerContext ||
_threadingModel==CullThreadPerCameraDrawThreadPerContext)
{
_startRenderingBarrier = 0;
_endRenderingDispatchBarrier = 0;
_endDynamicDrawBlock = new osg::EndOfDynamicDrawBlock(numViewerDoubleBufferedRenderingOperation);
#ifndef OSGUTIL_RENDERBACKEND_USE_REF_PTR
if (!osg::Referenced::getDeleteHandler()) osg::Referenced::setDeleteHandler(new osg::DeleteHandler(2));
else osg::Referenced::getDeleteHandler()->setNumFramesToRetainObjects(2);
#endif
}
if (numThreadsOnStartBarrier>1)
{
_startRenderingBarrier = new osg::BarrierOperation(numThreadsOnStartBarrier, osg::BarrierOperation::NO_OPERATION);
}
if (numThreadsOnEndBarrier>1)
{
_endRenderingDispatchBarrier = new osg::BarrierOperation(numThreadsOnEndBarrier, _endBarrierOperation);
}
osg::ref_ptr<osg::BarrierOperation> swapReadyBarrier = contexts.empty() ? 0 : new osg::BarrierOperation(contexts.size(), osg::BarrierOperation::NO_OPERATION);
osg::ref_ptr<osg::SwapBuffersOperation> swapOp = new osg::SwapBuffersOperation();
typedef std::map<OpenThreads::Thread*, int> ThreadAffinityMap;
ThreadAffinityMap threadAffinityMap;
unsigned int processNum = 1;
for(citr = contexts.begin();
citr != contexts.end();
++citr, ++processNum)
{
osg::GraphicsContext* gc = (*citr);
if (!gc->isRealized())
{
OSG_INFO<<"ViewerBase::startThreading() : Realizng window "<<gc<<std::endl;
gc->realize();
}
gc->getState()->setDynamicObjectRenderingCompletedCallback(_endDynamicDrawBlock.get());
// create the a graphics thread for this context
gc->createGraphicsThread();
if (affinity) gc->getGraphicsThread()->setProcessorAffinity(processNum % numProcessors);
threadAffinityMap[gc->getGraphicsThread()] = processNum % numProcessors;
// add the startRenderingBarrier
if (_threadingModel==CullDrawThreadPerContext && _startRenderingBarrier.valid()) gc->getGraphicsThread()->add(_startRenderingBarrier.get());
// add the rendering operation itself.
gc->getGraphicsThread()->add(new osg::RunOperations());
if (_threadingModel==CullDrawThreadPerContext && _endBarrierPosition==BeforeSwapBuffers && _endRenderingDispatchBarrier.valid())
{
// add the endRenderingDispatchBarrier
gc->getGraphicsThread()->add(_endRenderingDispatchBarrier.get());
}
if (swapReadyBarrier.valid()) gc->getGraphicsThread()->add(swapReadyBarrier.get());
// add the swap buffers
gc->getGraphicsThread()->add(swapOp.get());
if (_threadingModel==CullDrawThreadPerContext && _endBarrierPosition==AfterSwapBuffers && _endRenderingDispatchBarrier.valid())
{
// add the endRenderingDispatchBarrier
gc->getGraphicsThread()->add(_endRenderingDispatchBarrier.get());
}
}
if (_threadingModel==CullThreadPerCameraDrawThreadPerContext && numThreadsOnStartBarrier>1)
{
Cameras::iterator camItr;
for(camItr = cameras.begin();
camItr != cameras.end();
++camItr, ++processNum)
{
osg::Camera* camera = *camItr;
camera->createCameraThread();
if (affinity) camera->getCameraThread()->setProcessorAffinity(processNum % numProcessors);
threadAffinityMap[camera->getCameraThread()] = processNum % numProcessors;
osg::GraphicsContext* gc = camera->getGraphicsContext();
// add the startRenderingBarrier
if (_startRenderingBarrier.valid()) camera->getCameraThread()->add(_startRenderingBarrier.get());
Renderer* renderer = dynamic_cast<Renderer*>(camera->getRenderer());
renderer->setGraphicsThreadDoesCull(false);
camera->getCameraThread()->add(renderer);
if (_endRenderingDispatchBarrier.valid())
{
// add the endRenderingDispatchBarrier
gc->getGraphicsThread()->add(_endRenderingDispatchBarrier.get());
}
}
for(camItr = cameras.begin();
camItr != cameras.end();
++camItr)
{
osg::Camera* camera = *camItr;
if (camera->getCameraThread() && !camera->getCameraThread()->isRunning())
{
OSG_INFO<<" camera->getCameraThread()-> "<<camera->getCameraThread()<<std::endl;
camera->getCameraThread()->startThread();
}
}
}
#if 0
if (affinity)
{
OpenThreads::SetProcessorAffinityOfCurrentThread(0);
if (_scene.valid() && _scene->getDatabasePager())
{
#if 0
_scene->getDatabasePager()->setProcessorAffinity(1);
#else
_scene->getDatabasePager()->setProcessorAffinity(0);
#endif
}
}
#endif
#if 0
if (affinity)
{
for(ThreadAffinityMap::iterator titr = threadAffinityMap.begin();
titr != threadAffinityMap.end();
++titr)
{
titr->first->setProcessorAffinity(titr->second);
}
}
#endif
for(citr = contexts.begin();
citr != contexts.end();
++citr)
{
osg::GraphicsContext* gc = (*citr);
if (gc->getGraphicsThread() && !gc->getGraphicsThread()->isRunning())
{
OSG_INFO<<" gc->getGraphicsThread()->startThread() "<<gc->getGraphicsThread()<<std::endl;
gc->getGraphicsThread()->startThread();
// OpenThreads::Thread::YieldCurrentThread();
}
}
_threadsRunning = true;
OSG_INFO<<"Set up threading"<<std::endl;
}