expose some sleep timeout pybullet.setPhysicsEngineParameter(maxNumCmdPer1ms=100) or b3PhysicsParamSetMaxNumCommandsPer1ms,

if more commands than those are processed per millisecond, a 1ms sleep will follow, to avoid other threads being stalled.

examples/SharedMemory/PhysicsClientC_API.cpp

@@ -347,6 +347,16 @@ int b3PhysicsParamSetContactBreakingThreshold(b3SharedMemoryCommandHandle comman
 	command->m_updateFlags |= SIM_PARAM_UPDATE_CONTACT_BREAKING_THRESHOLD;
 	return 0;
 }
+int b3PhysicsParamSetMaxNumCommandsPer1ms(b3SharedMemoryCommandHandle commandHandle, int maxNumCmdPer1ms)
+{
+	struct SharedMemoryCommand* command = (struct SharedMemoryCommand*) commandHandle;
+	b3Assert(command->m_type == CMD_SEND_PHYSICS_SIMULATION_PARAMETERS);
+
+	command->m_physSimParamArgs.m_maxNumCmdPer1ms = maxNumCmdPer1ms;
+	command->m_updateFlags |= SIM_PARAM_MAX_CMD_PER_1MS;
+	return 0;
+
+}
 
 int b3PhysicsParamSetNumSolverIterations(b3SharedMemoryCommandHandle commandHandle, int numSolverIterations)
 {

examples/SharedMemory/PhysicsClientC_API.h

@@ -198,6 +198,7 @@ int b3PhysicsParamSetCollisionFilterMode(b3SharedMemoryCommandHandle commandHand
 int b3PhysicsParamSetUseSplitImpulse(b3SharedMemoryCommandHandle commandHandle, int useSplitImpulse);
 int b3PhysicsParamSetSplitImpulsePenetrationThreshold(b3SharedMemoryCommandHandle commandHandle, double splitImpulsePenetrationThreshold);
 int b3PhysicsParamSetContactBreakingThreshold(b3SharedMemoryCommandHandle commandHandle, double contactBreakingThreshold);
+int b3PhysicsParamSetMaxNumCommandsPer1ms(b3SharedMemoryCommandHandle commandHandle, int maxNumCmdPer1ms);
 
 //b3PhysicsParamSetInternalSimFlags is for internal/temporary/easter-egg/experimental demo purposes
 //Use at own risk: magic things may or my not happen when calling this API

examples/SharedMemory/PhysicsServerCommandProcessor.cpp

@@ -48,6 +48,7 @@ bool gResetSimulation = 0;
 int gVRTrackingObjectUniqueId = -1;
 btTransform gVRTrackingObjectTr = btTransform::getIdentity();
 
+int gMaxNumCmdPer1ms = 100;//experiment: add some delay to avoid threads starving other threads
 int gCreateObjectSimVR = -1;
 int gEnableKukaControl = 0;
 btVector3 gVRTeleportPos1(0,0,0);
@@ -3161,6 +3162,11 @@ bool PhysicsServerCommandProcessor::processCommand(const struct SharedMemoryComm
 					{
 						gContactBreakingThreshold = clientCmd.m_physSimParamArgs.m_contactBreakingThreshold;
 					}
+					if (clientCmd.m_updateFlags&SIM_PARAM_MAX_CMD_PER_1MS)
+					{
+						gMaxNumCmdPer1ms = clientCmd.m_physSimParamArgs.m_maxNumCmdPer1ms;
+					}
+
 					if (clientCmd.m_updateFlags&SIM_PARAM_UPDATE_COLLISION_FILTER_MODE)
 					{
 						m_data->m_broadphaseCollisionFilterCallback->m_filterMode = clientCmd.m_physSimParamArgs.m_collisionFilterMode;

examples/SharedMemory/PhysicsServerExample.cpp

@@ -277,7 +277,7 @@ struct MotionThreadLocalStorage
 
 
 float clampedDeltaTime  = 0.2;
-float sleepTimeThreshold = 8./1000.;
+extern int gMaxNumCmdPer1ms;
 
 
 void	MotionThreadFunc(void* userPtr,void* lsMemory)
@@ -289,6 +289,7 @@ void	MotionThreadFunc(void* userPtr,void* lsMemory)
 	//int workLeft = true;
 	b3Clock clock;
 	clock.reset();
+	b3Clock sleepClock;
 	bool init = true;
 	if (init)
 	{
@@ -299,6 +300,8 @@ void	MotionThreadFunc(void* userPtr,void* lsMemory)
 
 
 		double deltaTimeInSeconds = 0;
+		int numCmdSinceSleep1ms = 0;
+
 		do
 		{
 			BT_PROFILE("loop");
@@ -307,6 +310,19 @@ void	MotionThreadFunc(void* userPtr,void* lsMemory)
 				BT_PROFILE("usleep(0)");
 				b3Clock::usleep(0);
 			}
+
+			if (numCmdSinceSleep1ms>gMaxNumCmdPer1ms)
+			{
+				BT_PROFILE("usleep(1000)");
+				b3Clock::usleep(1000);
+				numCmdSinceSleep1ms = 0;
+				sleepClock.reset();
+			}
+			if (sleepClock.getTimeMilliseconds()>1)
+			{
+				sleepClock.reset();
+				numCmdSinceSleep1ms = 0;
+			}
 			double dt = double(clock.getTimeMicroseconds())/1000000.;
 			clock.reset();
 			deltaTimeInSeconds+= dt;
@@ -434,6 +450,7 @@ void	MotionThreadFunc(void* userPtr,void* lsMemory)
 			{
 				BT_PROFILE("processClientCommands");
 				args->m_physicsServerPtr->processClientCommands();
+				numCmdSinceSleep1ms++;
 			}
 			
 		} while (args->m_cs->getSharedParam(0)!=eRequestTerminateMotion);

examples/SharedMemory/SharedMemoryCommands.h

@@ -315,6 +315,7 @@ enum EnumSimParamUpdateFlags
 	SIM_PARAM_UPDATE_SPLIT_IMPULSE_PENETRATION_THRESHOLD = 256,
 	SIM_PARAM_UPDATE_COLLISION_FILTER_MODE=512,
 	SIM_PARAM_UPDATE_CONTACT_BREAKING_THRESHOLD = 1024,
+	SIM_PARAM_MAX_CMD_PER_1MS = 2048,
 };
 
 enum EnumLoadBunnyUpdateFlags
@@ -342,6 +343,7 @@ struct SendPhysicsSimulationParameters
 	int m_useSplitImpulse;
 	double m_splitImpulsePenetrationThreshold;
 	double m_contactBreakingThreshold;
+	int m_maxNumCmdPer1ms;
 	int m_internalSimFlags;
 	double m_defaultContactERP;
 	int m_collisionFilterMode;

examples/StandaloneMain/hellovr_opengl_main.cpp

@@ -659,9 +659,11 @@ void CMainApplication::Shutdown()
 		}
 	}
 
+	if (sExample)
+	{
 		sExample->exitPhysics();
 		delete sExample;
-
+	}
 	delete m_app;
 	m_app=0;
 	

examples/pybullet/pybullet.c

@@ -606,14 +606,14 @@ static PyObject* pybullet_setPhysicsEngineParameter(PyObject* self, PyObject* ar
 	int numSubSteps = -1;
 	int collisionFilterMode = -1;
 	double contactBreakingThreshold = -1;
-	
+	int maxNumCmdPer1ms = -1;
 	b3PhysicsClientHandle sm = 0;
 
 	int physicsClientId = 0;
-	static char *kwlist[] = { "fixedTimeStep", "numSolverIterations","useSplitImpulse","splitImpulsePenetrationThreshold", "numSubSteps","collisionFilterMode", "contactBreakingThreshold", "physicsClientId", NULL };
+	static char *kwlist[] = { "fixedTimeStep", "numSolverIterations","useSplitImpulse","splitImpulsePenetrationThreshold", "numSubSteps","collisionFilterMode", "contactBreakingThreshold", "maxNumCmdPer1ms", "physicsClientId", NULL };
 
-	if (!PyArg_ParseTupleAndKeywords(args, keywds, "|diidiidi", kwlist,&fixedTimeStep,&numSolverIterations,&useSplitImpulse,&splitImpulsePenetrationThreshold,&numSubSteps,
+	if (!PyArg_ParseTupleAndKeywords(args, keywds, "|diidiidii", kwlist,&fixedTimeStep,&numSolverIterations,&useSplitImpulse,&splitImpulsePenetrationThreshold,&numSubSteps,
-									 &collisionFilterMode, &contactBreakingThreshold, &physicsClientId))
+									 &collisionFilterMode, &contactBreakingThreshold, &maxNumCmdPer1ms, &physicsClientId))
 	{
 		return NULL;
 	}
@@ -658,7 +658,10 @@ static PyObject* pybullet_setPhysicsEngineParameter(PyObject* self, PyObject* ar
 		{
 			b3PhysicsParamSetContactBreakingThreshold(command,contactBreakingThreshold);
 		}
-
+		if (maxNumCmdPer1ms>=0)
+		{
+			b3PhysicsParamSetMaxNumCommandsPer1ms(command,maxNumCmdPer1ms);
+		}
 
 		//ret = b3PhysicsParamSetRealTimeSimulation(command, enableRealTimeSimulation);