OpenSceneGraph/examples/osgunittests/MultiThreadRead.cpp
Robert Osfield 6a67be2e32 Introduced CMake option OSG_PROVIDE_READFILE option that defaults to ON, but when switched to OFF disables the building of the osgDB::read*File() methods,
forcing users to use osgDB::readRef*File() methods.  The later is preferable as it closes a potential threading bug when using paging databases in conjunction
with the osgDB::Registry Object Cache.  This threading bug occurs when one thread gets an object from the Cache via an osgDB::read*File() call where only
a pointer to the object is passed back, so taking a reference to the object is delayed till it gets reassigned to a ref_ptr<>, but at the same time another
thread calls a flush of the Object Cache deleting this object as it's referenceCount is now zero.  Using osgDB::readREf*File() makes sure the a ref_ptr<> is
passed back and the referenceCount never goes to zero.

To ensure the OSG builds when OSG_PROVIDE_READFILE is to OFF the many cases of osgDB::read*File() usage had to be replaced with a ref_ptr<> osgDB::readRef*File()
usage.  The avoid this change causing lots of other client code to be rewritten to handle the use of ref_ptr<> in place of C pointer I introduced a serious of
templte methods in various class to adapt ref_ptr<> to the underly C pointer to be passed to old OSG API's, example of this is found in include/osg/Group:

    bool addChild(Node* child); // old method which can only be used with a Node*

    tempalte<class T> bool addChild(const osg::ref_ptr<T>& child) { return addChild(child.get()); } // adapter template method

These changes together cover 149 modified files, so it's a large submission. This extent of changes are warrent to make use of the Object Cache
and multi-threaded loaded more robust.



git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/branches/OpenSceneGraph-3.4@15165 16af8721-9629-0410-8352-f15c8da7e697
2015-10-22 14:14:53 +00:00

216 lines
6.8 KiB
C++

/* OpenSceneGraph example, osgunittests.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <osg/Referenced>
#include <osgDB/ReadFile>
#include <osgDB/Registry>
#include <OpenThreads/Thread>
#include <OpenThreads/ScopedLock>
struct RefBarrier : public osg::Referenced, public OpenThreads::Barrier
{
RefBarrier(int numThreads):
OpenThreads::Barrier(numThreads) {}
};
class ReadThread : public osg::Referenced, public OpenThreads::Thread
{
public:
ReadThread():
_done(false)
{
}
virtual ~ReadThread()
{
_done = true;
if (isRunning())
{
cancel();
join();
}
}
void addFileName(const std::string& filename)
{
_fileNames.push_back(filename);
}
void setStartBarrier(RefBarrier* barrier) { _startBarrier = barrier; }
void setEndBarrier(RefBarrier* barrier) { _endBarrier = barrier; }
virtual void run()
{
if (_startBarrier.valid())
{
#if VERBOSE
std::cout<<"Waiting on start block "<<this<<std::endl;
#endif
_startBarrier->block();
}
#if VERBOSE
std::cout<<"Starting "<<this<<std::endl;
#endif
do
{
if (!_fileNames.empty())
{
// take front filename;
std::string filename = _fileNames.front();
_fileNames.erase(_fileNames.begin());
#if VERBOSE
std::cout<<"Reading "<<filename;
#endif
osg::ref_ptr<osg::Node> node = osgDB::readRefNodeFile(filename);
#if VERBOSE
if (node.valid()) std::cout<<".. OK"<<std::endl;
else std::cout<<".. FAILED"<<std::endl;
#endif
}
} while (!testCancel() && !_fileNames.empty() && !_done);
if (_endBarrier.valid())
{
#if VERBOSE
std::cout<<"Waiting on end block "<<this<<std::endl;
#endif
_endBarrier->block();
}
#if VERBOSE
std::cout<<"Completed"<<this<<std::endl;
#endif
}
typedef std::list<std::string> FileNames;
FileNames _fileNames;
bool _done;
osg::ref_ptr<RefBarrier> _startBarrier;
osg::ref_ptr<RefBarrier> _endBarrier;
};
class SerializerReadFileCallback : public osgDB::Registry::ReadFileCallback
{
public:
virtual osgDB::ReaderWriter::ReadResult openArchive(const std::string& filename,osgDB::ReaderWriter::ArchiveStatus status, unsigned int indexBlockSizeHint, const osgDB::ReaderWriter::Options* useObjectCache)
{
OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
return osgDB::Registry::instance()->openArchiveImplementation(filename, status, indexBlockSizeHint, useObjectCache);
}
virtual osgDB::ReaderWriter::ReadResult readObject(const std::string& filename, const osgDB::ReaderWriter::Options* options)
{
OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
return osgDB::Registry::instance()->readObjectImplementation(filename,options);
}
virtual osgDB::ReaderWriter::ReadResult readImage(const std::string& filename, const osgDB::ReaderWriter::Options* options)
{
OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
return osgDB::Registry::instance()->readImageImplementation(filename,options);
}
virtual osgDB::ReaderWriter::ReadResult readHeightField(const std::string& filename, const osgDB::ReaderWriter::Options* options)
{
OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
return osgDB::Registry::instance()->readHeightFieldImplementation(filename,options);
}
virtual osgDB::ReaderWriter::ReadResult readNode(const std::string& filename, const osgDB::ReaderWriter::Options* options)
{
OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
return osgDB::Registry::instance()->readNodeImplementation(filename,options);
}
virtual osgDB::ReaderWriter::ReadResult readShader(const std::string& filename, const osgDB::ReaderWriter::Options* options)
{
OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
return osgDB::Registry::instance()->readShaderImplementation(filename,options);
}
protected:
virtual ~SerializerReadFileCallback() {}
OpenThreads::Mutex _mutex;
};
void runMultiThreadReadTests(int numThreads, osg::ArgumentParser& arguments)
{
#if VERBOSE
osg::notify(osg::NOTICE)<<"runMultiThreadReadTests() -- running"<<std::endl;
#endif
if (arguments.read("preload"))
{
osgDB::Registry::instance()->loadLibrary(osgDB::Registry::instance()->createLibraryNameForExtension("osg"));
osgDB::Registry::instance()->loadLibrary(osgDB::Registry::instance()->createLibraryNameForExtension("rgb"));
osgDB::Registry::instance()->loadLibrary(osgDB::Registry::instance()->createLibraryNameForExtension("jpeg"));
osgDB::Registry::instance()->loadLibrary(osgDB::Registry::instance()->createLibraryNameForExtension("ive"));
}
if (arguments.read("serialize"))
{
osgDB::Registry::instance()->setReadFileCallback(new SerializerReadFileCallback());
}
osg::ref_ptr<RefBarrier> startBarrier = new RefBarrier(numThreads+1);
osg::ref_ptr<RefBarrier> endBarrier = new RefBarrier(numThreads+1);
typedef std::list< osg::ref_ptr<ReadThread> > ReadThreads;
ReadThreads readThreads;
for(int i=0; i<numThreads; ++i)
{
osg::ref_ptr<ReadThread> readThread = new ReadThread;
readThread->setProcessorAffinity(numThreads % 4);
readThread->setStartBarrier(startBarrier.get());
readThread->setEndBarrier(endBarrier.get());
readThread->addFileName("cessna.osgt");
readThread->addFileName("glider.osgt");
readThread->addFileName("town.ive");
readThreads.push_back(readThread.get());
readThread->start();
}
startBarrier->block();
endBarrier->block();
#if VERBOSE
osg::notify(osg::NOTICE)<<"runMultiThreadReadTests() -- completed."<<std::endl;
#endif
}