bullet3/examples/MultiThreading/MultiThreadingExample.cpp

#include "MultiThreadingExample.h"
#include "../CommonInterfaces/CommonGraphicsAppInterface.h"
#include "../CommonInterfaces/CommonRenderInterface.h"

#include "../CommonInterfaces/CommonExampleInterface.h"
#include "LinearMath/btTransform.h"

#include "../CommonInterfaces/CommonGUIHelperInterface.h"
#include "../RenderingExamples/TimeSeriesCanvas.h"
#include "stb_image/stb_image.h"
#include "Bullet3Common/b3Quaternion.h"
#include "Bullet3Common/b3Matrix3x3.h"
#include "../CommonInterfaces/CommonParameterInterface.h"

#include "LinearMath/btAlignedObjectArray.h"
#define  stdvector btAlignedObjectArray

#define MAGIC_RESET_NUMBER 64738

void	SampleThreadFunc(void* userPtr,void* lsMemory);
void*	SamplelsMemoryFunc();


#include <stdio.h>
//#include "BulletMultiThreaded/PlatformDefinitions.h"

#ifndef _WIN32
#include "b3PosixThreadSupport.h"

b3ThreadSupportInterface* createThreadSupport(int numThreads)
{
	b3PosixThreadSupport::ThreadConstructionInfo constructionInfo("testThreads",
                                                                SampleThreadFunc,
                                                                SamplelsMemoryFunc,
                                                                numThreads);
    b3ThreadSupportInterface* threadSupport = new b3PosixThreadSupport(constructionInfo);

	return threadSupport;

}


#elif defined( _WIN32)
#include "b3Win32ThreadSupport.h"

b3ThreadSupportInterface* createThreadSupport(int numThreads)
{
	b3Win32ThreadSupport::Win32ThreadConstructionInfo threadConstructionInfo("testThreads",SampleThreadFunc,SamplelsMemoryFunc,numThreads);
	b3Win32ThreadSupport* threadSupport = new b3Win32ThreadSupport(threadConstructionInfo);
	return threadSupport;

}
#endif

struct SampleJobInterface
{
    virtual void executeJob(int threadIndex)=0;
};

struct SampleJob1 : public  SampleJobInterface
{
    float m_fakeWork;
    int m_jobId;
    
    SampleJob1(int jobId)
    :m_fakeWork(0),
    m_jobId(jobId)
    {
    }
    virtual ~SampleJob1() {}

    virtual void executeJob(int threadIndex)
    {
        printf("start SampleJob1 %d using threadIndex %d\n",m_jobId,threadIndex);
     //do some fake work
		for (int i=0;i<1000000;i++)
			m_fakeWork = b3Scalar(1.21)*m_fakeWork;
        printf("finished SampleJob1 %d using threadIndex %d\n",m_jobId,threadIndex);
    }
};


struct	SampleArgs
{
	SampleArgs()
	{
	}
	b3CriticalSection* m_cs;
	
	btAlignedObjectArray<SampleJobInterface*> m_jobQueue;
	
	void submitJob(SampleJobInterface* job)
	{
	     m_cs->lock();
         m_jobQueue.push_back(job);
         m_cs->unlock();
	}
	SampleJobInterface* consumeJob()
	{
	    SampleJobInterface* job = 0;
	     m_cs->lock();
	     int sz = m_jobQueue.size();
	     if (sz)
         {
            job = m_jobQueue[sz-1];
            m_jobQueue.pop_back();
         }
         m_cs->unlock();
	    return job;
	}
};
SampleArgs	args;
struct SampleThreadLocalStorage
{
	int threadId;
};


void	SampleThreadFunc(void* userPtr,void* lsMemory)
{
	printf("thread started\n");

	SampleThreadLocalStorage* localStorage = (SampleThreadLocalStorage*) lsMemory;

	SampleArgs* args = (SampleArgs*) userPtr;
	
	bool requestExit = false;
	while (!requestExit)
	{
		SampleJobInterface* job = args->consumeJob();
		if (job)
        {
            job->executeJob(localStorage->threadId);
        }
		
		args->m_cs->lock();
		int exitMagicNumber = args->m_cs->getSharedParam(1);
		requestExit = (exitMagicNumber==MAGIC_RESET_NUMBER);
		args->m_cs->unlock();
	
	}

	printf("finished\n");
	//do nothing
}


void*	SamplelsMemoryFunc()
{
	//don't create local store memory, just return 0
	return new SampleThreadLocalStorage;
}






class MultiThreadingExample : public CommonExampleInterface
{
    CommonGraphicsApp* m_app;
	GUIHelperInterface* m_guiHelper;
    int m_exampleIndex;
    b3ThreadSupportInterface* m_threadSupport;
    btAlignedObjectArray<SampleJob1*> m_jobs;
    int m_numThreads;
public:
    
    MultiThreadingExample(GUIHelperInterface* guiHelper, int tutorialIndex)
    :m_app(guiHelper->getAppInterface()),
	m_guiHelper(guiHelper),
	m_exampleIndex(tutorialIndex),
	m_threadSupport(0),
	m_numThreads(8)
    {
		int numBodies = 1;
		
		m_app->setUpAxis(1);
		m_app->m_renderer->enableBlend(true);
		
    }
    virtual ~MultiThreadingExample()
    {


		m_app->m_renderer->enableBlend(false);
    }
    
   
	 virtual void        renderScene()
    {
} 
    virtual void    initPhysics()
    {
        b3Printf("initPhysics");
        
        

        m_threadSupport = createThreadSupport(m_numThreads);



        for (int i=0;i<m_threadSupport->getNumTasks();i++)
        {
            SampleThreadLocalStorage* storage = (SampleThreadLocalStorage*)m_threadSupport->getThreadLocalMemory(i);
            b3Assert(storage);
            storage->threadId = i;
        }


        
        args.m_cs = m_threadSupport->createCriticalSection();
        args.m_cs->setSharedParam(0,100);
        
        for (int i=0;i<100;i++)
        {
            SampleJob1* job = new SampleJob1(i);
            args.submitJob(job);
        }

       
        int i;
        for (i=0;i<m_numThreads;i++)
        {
            m_threadSupport->runTask(B3_THREAD_SCHEDULE_TASK, (void*) &args, i);
        }
         b3Printf("Threads started");

    }
    virtual void    exitPhysics()
    {
        b3Printf("exitPhysics, stopping threads");
       	bool blockingWait =false;
       	 int arg0,arg1;
       	   
        args.m_cs->lock();
        //terminate all threads
        args.m_cs->setSharedParam(1,MAGIC_RESET_NUMBER);
        args.m_cs->unlock();
       	   
        if (blockingWait)
        {
            for (int i=0;i<m_numThreads;i++)
            {
                m_threadSupport->waitForResponse(&arg0,&arg1);
                printf("finished waiting for response: %d %d\n", arg0,arg1);
            }
        } else
        {
            int numActiveThreads = m_numThreads;
            while (numActiveThreads)
            {
                if (m_threadSupport->isTaskCompleted(&arg0,&arg1,0))
                {
                    numActiveThreads--;
                    printf("numActiveThreads = %d\n",numActiveThreads);

                } else
                {
    //				printf("polling..");
                }
            };
        }
        
        delete m_threadSupport;
        
        b3Printf("Threads stopped");
        for (int i=0;i<m_jobs.size();i++)
        {
         delete m_jobs[i];
        }
        m_jobs.clear();
        	
    }
	
    virtual void	stepSimulation(float deltaTime)
    {
		
		
		
    }

	

    virtual void	physicsDebugDraw(int debugDrawFlags)
    {
      
		
    }
    virtual bool	mouseMoveCallback(float x,float y)
    {
		return false;   
    }
    virtual bool	mouseButtonCallback(int button, int state, float x, float y)
    {
        return false;   
    }
    virtual bool	keyboardCallback(int key, int state)
    {
        return false;   
    }
  

	virtual void resetCamera()
	{
		float dist = 10.5;
		float pitch = 136;
		float yaw = 32;
		float targetPos[3]={0,0,0};
		if (m_app->m_renderer  && m_app->m_renderer->getActiveCamera())
		{
			m_app->m_renderer->getActiveCamera()->setCameraDistance(dist);
			m_app->m_renderer->getActiveCamera()->setCameraPitch(pitch);
			m_app->m_renderer->getActiveCamera()->setCameraYaw(yaw);
			m_app->m_renderer->getActiveCamera()->setCameraTargetPosition(targetPos[0],targetPos[1],targetPos[2]);
		}
	}
};



class CommonExampleInterface*    MultiThreadingExampleCreateFunc(struct CommonExampleOptions& options)
{
	return new MultiThreadingExample(options.m_guiHelper, options.m_option);
}