dali-physics/third-party/bullet3/src/BulletDynamics/Dynamics/btDiscreteDynamicsWorldMt.h

   1 /*
   2 Bullet Continuous Collision Detection and Physics Library
   3 Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org
   4
   5 This software is provided 'as-is', without any express or implied warranty.
   6 In no event will the authors be held liable for any damages arising from the use of this software.
   7 Permission is granted to anyone to use this software for any purpose,
   8 including commercial applications, and to alter it and redistribute it freely,
   9 subject to the following restrictions:
  10
  11 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.
  12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
  13 3. This notice may not be removed or altered from any source distribution.
  14 */
  15
  16 #ifndef BT_DISCRETE_DYNAMICS_WORLD_MT_H
  17 #define BT_DISCRETE_DYNAMICS_WORLD_MT_H
  18
  19 #include "btDiscreteDynamicsWorld.h"
  20 #include "btSimulationIslandManagerMt.h"
  21 #include "BulletDynamics/ConstraintSolver/btConstraintSolver.h"
  22
  23 ///
  24 /// btConstraintSolverPoolMt - masquerades as a constraint solver, but really it is a threadsafe pool of them.
  25 ///
  26 ///  Each solver in the pool is protected by a mutex.  When solveGroup is called from a thread,
  27 ///  the pool looks for a solver that isn't being used by another thread, locks it, and dispatches the
  28 ///  call to the solver.
  29 ///  So long as there are at least as many solvers as there are hardware threads, it should never need to
  30 ///  spin wait.
  31 ///
  32 class btConstraintSolverPoolMt : public btConstraintSolver
  33 {
  34 public:
  35         // create the solvers for me
  36         explicit btConstraintSolverPoolMt(int numSolvers);
  37
  38         // pass in fully constructed solvers (destructor will delete them)
  39         btConstraintSolverPoolMt(btConstraintSolver** solvers, int numSolvers);
  40
  41         virtual ~btConstraintSolverPoolMt();
  42
  43         ///solve a group of constraints
  44         virtual btScalar solveGroup(btCollisionObject** bodies,
  45                                                                 int numBodies,
  46                                                                 btPersistentManifold** manifolds,
  47                                                                 int numManifolds,
  48                                                                 btTypedConstraint** constraints,
  49                                                                 int numConstraints,
  50                                                                 const btContactSolverInfo& info,
  51                                                                 btIDebugDraw* debugDrawer,
  52                                                                 btDispatcher* dispatcher) BT_OVERRIDE;
  53
  54         virtual void reset() BT_OVERRIDE;
  55         virtual btConstraintSolverType getSolverType() const BT_OVERRIDE { return m_solverType; }
  56
  57 private:
  58         const static size_t kCacheLineSize = 128;
  59         struct ThreadSolver
  60         {
  61                 btConstraintSolver* solver;
  62                 btSpinMutex mutex;
  63                 char _cachelinePadding[kCacheLineSize - sizeof(btSpinMutex) - sizeof(void*)];  // keep mutexes from sharing a cache line
  64         };
  65         btAlignedObjectArray<ThreadSolver> m_solvers;
  66         btConstraintSolverType m_solverType;
  67
  68         ThreadSolver* getAndLockThreadSolver();
  69         void init(btConstraintSolver** solvers, int numSolvers);
  70 };
  71
  72 ///
  73 /// btDiscreteDynamicsWorldMt -- a version of DiscreteDynamicsWorld with some minor changes to support
  74 ///                              solving simulation islands on multiple threads.
  75 ///
  76 ///  Should function exactly like btDiscreteDynamicsWorld.
  77 ///  Also 3 methods that iterate over all of the rigidbodies can run in parallel:
  78 ///     - predictUnconstraintMotion
  79 ///     - integrateTransforms
  80 ///     - createPredictiveContacts
  81 ///
  82 ATTRIBUTE_ALIGNED16(class)
  83 btDiscreteDynamicsWorldMt : public btDiscreteDynamicsWorld
  84 {
  85 protected:
  86         btConstraintSolver* m_constraintSolverMt;
  87
  88         virtual void solveConstraints(btContactSolverInfo & solverInfo) BT_OVERRIDE;
  89
  90         virtual void predictUnconstraintMotion(btScalar timeStep) BT_OVERRIDE;
  91
  92         struct UpdaterCreatePredictiveContacts : public btIParallelForBody
  93         {
  94                 btScalar timeStep;
  95                 btRigidBody** rigidBodies;
  96                 btDiscreteDynamicsWorldMt* world;
  97
  98                 void forLoop(int iBegin, int iEnd) const BT_OVERRIDE
  99                 {
 100                         world->createPredictiveContactsInternal(&rigidBodies[iBegin], iEnd - iBegin, timeStep);
 101                 }
 102         };
 103         virtual void createPredictiveContacts(btScalar timeStep) BT_OVERRIDE;
 104
 105         struct UpdaterIntegrateTransforms : public btIParallelForBody
 106         {
 107                 btScalar timeStep;
 108                 btRigidBody** rigidBodies;
 109                 btDiscreteDynamicsWorldMt* world;
 110
 111                 void forLoop(int iBegin, int iEnd) const BT_OVERRIDE
 112                 {
 113                         world->integrateTransformsInternal(&rigidBodies[iBegin], iEnd - iBegin, timeStep);
 114                 }
 115         };
 116         virtual void integrateTransforms(btScalar timeStep) BT_OVERRIDE;
 117
 118 public:
 119         BT_DECLARE_ALIGNED_ALLOCATOR();
 120
 121         btDiscreteDynamicsWorldMt(btDispatcher * dispatcher,
 122                                                           btBroadphaseInterface * pairCache,
 123                                                           btConstraintSolverPoolMt * solverPool,        // Note this should be a solver-pool for multi-threading
 124                                                           btConstraintSolver * constraintSolverMt,      // single multi-threaded solver for large islands (or NULL)
 125                                                           btCollisionConfiguration * collisionConfiguration);
 126         virtual ~btDiscreteDynamicsWorldMt();
 127
 128         virtual int stepSimulation(btScalar timeStep, int maxSubSteps, btScalar fixedTimeStep) BT_OVERRIDE;
 129 };
 130
 131 #endif  //BT_DISCRETE_DYNAMICS_WORLD_H