CPU GayBerneForce uses common neighbor list

platforms/cpu/include/CpuGayBerneForce.h

@@ -52,11 +52,6 @@ public:
      */
     CpuGayBerneForce(const GayBerneForce& force);
 
-    /**
-     * Destructor.
-     */
-    ~CpuGayBerneForce();
-
     /**
      * Compute the interaction.
      *
@@ -72,7 +67,12 @@ public:
     /**
      * This routine contains the code executed by each thread.
      */
-    void threadComputeForce(ThreadPool& threads, int threadIndex);
+    void threadComputeForce(ThreadPool& threads, int threadIndex, CpuNeighborList* neighborList);
+    
+    /**
+     * Get the exclusions being used by the force.
+     */
+    const std::vector<std::set<int> >& getExclusions() const;
 
 private:
     struct ParticleInfo;
@@ -86,7 +86,6 @@ private:
     bool useSwitchingFunction;
     std::vector<RealOpenMM> s;
     std::vector<Matrix> A, B, G;
-    CpuNeighborList* neighborList;
     std::vector<double> threadEnergy;
     std::vector<std::vector<RealVec> > threadTorque;
     // The following variables are used to make information accessible to the individual threads.

platforms/cpu/include/CpuPlatform.h

@@ -82,7 +82,7 @@ class CpuPlatform::PlatformData {
 public:
     PlatformData(int numParticles, int numThreads);
     ~PlatformData();
-    void requestNeighborList(double cutoffDistance, double padding, bool useExclusions, std::vector<std::set<int> >& exclusionList);
+    void requestNeighborList(double cutoffDistance, double padding, bool useExclusions, const std::vector<std::set<int> >& exclusionList);
     AlignedArray<float> posq;
     std::vector<AlignedArray<float> > threadForce;
     ThreadPool threads;

platforms/cpu/src/CpuGayBerneForce.cpp

@@ -41,15 +41,16 @@ using namespace std;
 
 class CpuGayBerneForce::ComputeTask : public ThreadPool::Task {
 public:
-    ComputeTask(CpuGayBerneForce& owner) : owner(owner) {
+    ComputeTask(CpuGayBerneForce& owner, CpuNeighborList* neighborList) : owner(owner), neighborList(neighborList) {
     }
     void execute(ThreadPool& threads, int threadIndex) {
-        owner.threadComputeForce(threads, threadIndex);
+        owner.threadComputeForce(threads, threadIndex, neighborList);
     }
     CpuGayBerneForce& owner;
+    CpuNeighborList* neighborList;
 };
 
-CpuGayBerneForce::CpuGayBerneForce(const GayBerneForce& force) : neighborList(NULL) {
+CpuGayBerneForce::CpuGayBerneForce(const GayBerneForce& force) {
     // Record the force parameters.
 
     int numParticles = force.getNumParticles();
@@ -85,8 +86,6 @@ CpuGayBerneForce::CpuGayBerneForce(const GayBerneForce& force) : neighborList(NU
     cutoffDistance = force.getCutoffDistance();
     switchingDistance = force.getSwitchingDistance();
     useSwitchingFunction = force.getUseSwitchingFunction();
-    if (nonbondedMethod != GayBerneForce::NoCutoff)
-        neighborList = new CpuNeighborList(4);
 
     // Allocate workspace for calculations.
 
@@ -103,9 +102,8 @@ CpuGayBerneForce::CpuGayBerneForce(const GayBerneForce& force) : neighborList(NU
     }
 }
 
-CpuGayBerneForce::~CpuGayBerneForce() {
-    if (neighborList != NULL)
-        delete neighborList;
+const vector<set<int> >& CpuGayBerneForce::getExclusions() const {
+    return particleExclusions;
 }
 
 RealOpenMM CpuGayBerneForce::calculateForce(const vector<RealVec>& positions, std::vector<RealVec>& forces, std::vector<AlignedArray<float> >& threadForce, RealVec* boxVectors, CpuPlatform::PlatformData& data) {
@@ -115,12 +113,6 @@ RealOpenMM CpuGayBerneForce::calculateForce(const vector<RealVec>& positions, st
             throw OpenMMException("The periodic box size has decreased to less than twice the nonbonded cutoff.");
     }
 
-    // Build the neighbor list.
-    
-    int numParticles = particles.size();
-    if (nonbondedMethod != GayBerneForce::NoCutoff)
-        neighborList->computeNeighborList(numParticles, data.posq, particleExclusions, boxVectors, nonbondedMethod == GayBerneForce::CutoffPeriodic, cutoffDistance, data.threads);
-
     // First find the orientations of the particles and compute the matrices we'll be needing.
 
     computeEllipsoidFrames(positions);
@@ -140,7 +132,7 @@ RealOpenMM CpuGayBerneForce::calculateForce(const vector<RealVec>& positions, st
     
     // Signal the threads to compute the pairwise interactions.
     
-    ComputeTask task(*this);
+    ComputeTask task(*this, data.neighborList);
     threads.execute(task);
     threads.waitForThreads();
     
@@ -162,7 +154,7 @@ RealOpenMM CpuGayBerneForce::calculateForce(const vector<RealVec>& positions, st
     return energy;
 }
 
-void CpuGayBerneForce::threadComputeForce(ThreadPool& threads, int threadIndex) {
+void CpuGayBerneForce::threadComputeForce(ThreadPool& threads, int threadIndex, CpuNeighborList* neighborList) {
     int numParticles = particles.size();
     int numThreads = threads.getNumThreads();
     threadEnergy[threadIndex] = 0;
@@ -198,14 +190,15 @@ void CpuGayBerneForce::threadComputeForce(ThreadPool& threads, int threadIndex)
             int blockIndex = gmx_atomic_fetch_add(reinterpret_cast<gmx_atomic_t*>(atomicCounter), 1);
             if (blockIndex >= neighborList->getNumBlocks())
                 break;
-            const int* blockAtom = &neighborList->getSortedAtoms()[4*blockIndex];
+            const int blockSize = neighborList->getBlockSize();
+            const int* blockAtom = &neighborList->getSortedAtoms()[blockSize*blockIndex];
             const vector<int>& neighbors = neighborList->getBlockNeighbors(blockIndex);
             const vector<char>& exclusions = neighborList->getBlockExclusions(blockIndex);
             for (int i = 0; i < (int) neighbors.size(); i++) {
                 int first = neighbors[i];
                 if (particles[first].sqrtEpsilon == 0.0f)
                     continue;
-                for (int k = 0; k < 4; k++) {
+                for (int k = 0; k < blockSize; k++) {
                     if ((exclusions[i] & (1<<k)) == 0) {
                         int second = blockAtom[k];
                         if (particles[second].sqrtEpsilon == 0.0f)

platforms/cpu/src/CpuKernels.cpp

@@ -1212,6 +1212,10 @@ CpuCalcGayBerneForceKernel::~CpuCalcGayBerneForceKernel() {
 void CpuCalcGayBerneForceKernel::initialize(const System& system, const GayBerneForce& force) {
     ixn = new CpuGayBerneForce(force);
     data.isPeriodic = (force.getNonbondedMethod() == GayBerneForce::CutoffPeriodic);
+    if (force.getNonbondedMethod() != GayBerneForce::NoCutoff) {
+        double cutoff = force.getCutoffDistance();
+        data.requestNeighborList(cutoff, 0.1*cutoff, true, ixn->getExclusions());
+    }
 }
 
 double CpuCalcGayBerneForceKernel::execute(ContextImpl& context, bool includeForces, bool includeEnergy) {

platforms/cpu/src/CpuPlatform.cpp

@@ -156,7 +156,7 @@ CpuPlatform::PlatformData::~PlatformData() {
 
 bool isVec8Supported();
 
-void CpuPlatform::PlatformData::requestNeighborList(double cutoffDistance, double padding, bool useExclusions, vector<set<int> >& exclusionList) {
+void CpuPlatform::PlatformData::requestNeighborList(double cutoffDistance, double padding, bool useExclusions, const vector<set<int> >& exclusionList) {
     if (neighborList == NULL)
         neighborList = new CpuNeighborList(isVec8Supported() ? 8 : 4);
     if (cutoffDistance > cutoff)