add example/MultiThreading functions

examples/MultiThreading/main.cpp

@@ -0,0 +1,177 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2010 Erwin Coumans  http://bulletphysics.org
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it freely,
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+/// ThreadingDemo shows how to use the cross platform thread support interface.
+/// You can start threads and perform a blocking wait for completion
+/// Under Windows it uses Win32 Threads. On Mac and Linux it uses pthreads. On PlayStation 3 Cell SPU it uses SPURS.
+
+/// June 2010
+/// New: critical section/barriers and non-blocking polling for completion
+
+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	SampleArgs
+{
+	SampleArgs()
+		:m_fakeWork(1)
+	{
+	}
+	b3CriticalSection* m_cs;
+	float m_fakeWork;
+};
+
+struct SampleThreadLocalStorage
+{
+	int threadId;
+};
+
+
+void	SampleThreadFunc(void* userPtr,void* lsMemory)
+{
+	printf("thread started\n");
+
+	SampleThreadLocalStorage* localStorage = (SampleThreadLocalStorage*) lsMemory;
+
+	SampleArgs* args = (SampleArgs*) userPtr;
+	int workLeft = true;
+	while (workLeft)
+	{
+		args->m_cs->lock();
+		int count = args->m_cs->getSharedParam(0);
+		args->m_cs->setSharedParam(0,count-1);
+		args->m_cs->unlock();
+		if (count>0)
+		{
+			printf("thread %d processed number %d\n",localStorage->threadId, count);
+		}
+		//do some fake work
+		for (int i=0;i<1000000;i++)
+			args->m_fakeWork = b3Scalar(1.21)*args->m_fakeWork;
+		workLeft = count>0;
+	}
+	printf("finished\n");
+	//do nothing
+}
+
+
+void*	SamplelsMemoryFunc()
+{
+	//don't create local store memory, just return 0
+	return new SampleThreadLocalStorage;
+}
+
+
+
+
+
+
+
+
+
+
+int main(int argc,char** argv)
+{
+	int numThreads = 8;
+
+	b3ThreadSupportInterface* threadSupport = createThreadSupport(numThreads);
+
+
+
+	for (int i=0;i<threadSupport->getNumTasks();i++)
+	{
+		SampleThreadLocalStorage* storage = (SampleThreadLocalStorage*)threadSupport->getThreadLocalMemory(i);
+		b3Assert(storage);
+		storage->threadId = i;
+	}
+
+
+	SampleArgs	args;
+	args.m_cs = threadSupport->createCriticalSection();
+	args.m_cs->setSharedParam(0,100);
+
+
+	int arg0,arg1;
+	int i;
+	for (i=0;i<numThreads;i++)
+	{
+		threadSupport->sendRequest(B3_THREAD_SCHEDULE_TASK, (void*) &args, i);
+	}
+
+	bool blockingWait =false;
+	if (blockingWait)
+	{
+		for (i=0;i<numThreads;i++)
+		{
+			threadSupport->waitForResponse(&arg0,&arg1);
+			printf("finished waiting for response: %d %d\n", arg0,arg1);
+		}
+	} else
+	{
+		int numActiveThreads = numThreads;
+		while (numActiveThreads)
+		{
+			if (threadSupport->isTaskCompleted(&arg0,&arg1,0))
+			{
+				numActiveThreads--;
+				printf("numActiveThreads = %d\n",numActiveThreads);
+
+			} else
+			{
+//				printf("polling..");
+			}
+		};
+	}
+
+printf("stopping threads\n");
+
+	delete threadSupport;
+	printf("Press ENTER to quit\n");
+	getchar();
+	return 0;
+}