Saxum/extern/bullet/src/BulletMultiThreaded/SpuLibspe2Support.cpp

/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2007 Erwin Coumans  http://bulletphysics.com

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.
*/

#ifdef USE_LIBSPE2

#include "SpuLibspe2Support.h"




//SpuLibspe2Support helps to initialize/shutdown libspe2, start/stop SPU tasks and communication
///Setup and initialize SPU/CELL/Libspe2
SpuLibspe2Support::SpuLibspe2Support(spe_program_handle_t *speprog, int numThreads)
{
	this->program = speprog;
	this->numThreads =  ((numThreads <= spe_cpu_info_get(SPE_COUNT_PHYSICAL_SPES, -1)) ? numThreads : spe_cpu_info_get(SPE_COUNT_PHYSICAL_SPES, -1));
}

///cleanup/shutdown Libspe2
SpuLibspe2Support::~SpuLibspe2Support()
{
	
	stopSPU();
}



///send messages to SPUs
void SpuLibspe2Support::sendRequest(uint32_t uiCommand, uint32_t uiArgument0, uint32_t uiArgument1)
{
	spe_context_ptr_t context;
	
	switch (uiCommand)
	{
	case CMD_SAMPLE_TASK_COMMAND:
	{
		//get taskdescription
		SpuSampleTaskDesc* taskDesc = (SpuSampleTaskDesc*) uiArgument0;

		btAssert(taskDesc->m_taskId<m_activeSpuStatus.size());

		//get status of SPU on which task should run
		btSpuStatus&	spuStatus = m_activeSpuStatus[taskDesc->m_taskId];

		//set data for spuStatus
		spuStatus.m_commandId = uiCommand;
		spuStatus.m_status = Spu_Status_Occupied; //set SPU as "occupied"
		spuStatus.m_taskDesc.p = taskDesc; 
		
		//get context
		context = data[taskDesc->m_taskId].context;
		
		
		taskDesc->m_mainMemoryPtr = reinterpret_cast<uint64_t> (spuStatus.m_lsMemory.p);
		

		break;
	}
	case CMD_GATHER_AND_PROCESS_PAIRLIST:
		{
			//get taskdescription
			SpuGatherAndProcessPairsTaskDesc* taskDesc = (SpuGatherAndProcessPairsTaskDesc*) uiArgument0;

			btAssert(taskDesc->taskId<m_activeSpuStatus.size());

			//get status of SPU on which task should run
			btSpuStatus&	spuStatus = m_activeSpuStatus[taskDesc->taskId];

			//set data for spuStatus
			spuStatus.m_commandId = uiCommand;
			spuStatus.m_status = Spu_Status_Occupied; //set SPU as "occupied"
			spuStatus.m_taskDesc.p = taskDesc; 
			
			//get context
			context = data[taskDesc->taskId].context;
			
			
			taskDesc->m_lsMemory = (CollisionTask_LocalStoreMemory*)spuStatus.m_lsMemory.p;
			
			break;
		}
	default:
		{
			///not implemented
			btAssert(0);
		}

	};

	
	//write taskdescription in mailbox
	unsigned int event = Spu_Mailbox_Event_Task;
	spe_in_mbox_write(context, &event, 1, SPE_MBOX_ANY_NONBLOCKING);

}

///check for messages from SPUs
void SpuLibspe2Support::waitForResponse(unsigned int *puiArgument0, unsigned int *puiArgument1)
{
	///We should wait for (one of) the first tasks to finish (or other SPU messages), and report its response
	
	///A possible response can be 'yes, SPU handled it', or 'no, please do a PPU fallback'
	
	btAssert(m_activeSpuStatus.size());

	
	int last = -1;
	
	//find an active spu/thread
	while(last < 0)
	{
		for (int i=0;i<m_activeSpuStatus.size();i++)
		{
			if ( m_activeSpuStatus[i].m_status == Spu_Status_Free)
			{
				last = i;
				break;
			}
		}
		if(last < 0)
			sched_yield();
	}



	btSpuStatus& spuStatus = m_activeSpuStatus[last];

	///need to find an active spu
	btAssert(last>=0);

	

	*puiArgument0 = spuStatus.m_taskId;
	*puiArgument1 = spuStatus.m_status;


}


void SpuLibspe2Support::startSPU()
{
	this->internal_startSPU();
}



///start the spus group (can be called at the beginning of each frame, to make sure that the right SPU program is loaded)
void SpuLibspe2Support::internal_startSPU()
{
	m_activeSpuStatus.resize(numThreads);
	
	
	for (int i=0; i < numThreads; i++)
	{
		
		if(data[i].context == NULL) 
		{
					
			 /* Create context */
			if ((data[i].context = spe_context_create(0, NULL)) == NULL)
			{
			      perror ("Failed creating context");
		          exit(1);
			}
	
			/* Load program into context */
			if(spe_program_load(data[i].context, this->program))
			{
			      perror ("Failed loading program");
		          exit(1);
			}
			
			m_activeSpuStatus[i].m_status = Spu_Status_Startup; 
			m_activeSpuStatus[i].m_taskId = i; 
			m_activeSpuStatus[i].m_commandId = 0; 
			m_activeSpuStatus[i].m_lsMemory.p = NULL; 
			
			
			data[i].entry = SPE_DEFAULT_ENTRY;
			data[i].flags = 0;
			data[i].argp.p = &m_activeSpuStatus[i];
			data[i].envp.p = NULL;
			
		    /* Create thread for each SPE context */
			if (pthread_create(&data[i].pthread, NULL, &ppu_pthread_function, &(data[i]) ))
			{
			      perror ("Failed creating thread");
		          exit(1);
			}
			/*
			else
			{
				printf("started thread %d\n",i);
			}*/
		}		
	}
	
	
	for (int i=0; i < numThreads; i++)
	{
		if(data[i].context != NULL) 
		{
			while( m_activeSpuStatus[i].m_status == Spu_Status_Startup)
			{
				// wait for spu to set up
				sched_yield();
			}
			printf("Spu %d is ready\n", i);
		}
	}
}

///tell the task scheduler we are done with the SPU tasks
void SpuLibspe2Support::stopSPU()
{
	// wait for all threads to finish 
	int i;
	for ( i = 0; i < this->numThreads; i++ ) 
	{ 
		
		unsigned int event = Spu_Mailbox_Event_Shutdown;
		spe_context_ptr_t context = data[i].context;
		spe_in_mbox_write(context, &event, 1, SPE_MBOX_ALL_BLOCKING);
		pthread_join (data[i].pthread, NULL); 
		
	} 
	// close SPE program 
	spe_image_close(program); 
	// destroy SPE contexts 
	for ( i = 0; i < this->numThreads; i++ ) 
	{ 
		if(data[i].context != NULL)
		{
			spe_context_destroy (data[i].context);
		}
	} 
	
	m_activeSpuStatus.clear();
	
}



#endif //USE_LIBSPE2