OpenCLContext.h

#ifndef OPENMM_OPENCLCONTEXT_H_
#define OPENMM_OPENCLCONTEXT_H_

/* -------------------------------------------------------------------------- *
 *                                   OpenMM                                   *
 * -------------------------------------------------------------------------- *
 * This is part of the OpenMM molecular simulation toolkit originating from   *
 * Simbios, the NIH National Center for Physics-Based Simulation of           *
 * Biological Structures at Stanford, funded under the NIH Roadmap for        *
 * Medical Research, grant U54 GM072970. See https://simtk.org.               *
 *                                                                            *
 * Portions copyright (c) 2009-2023 Stanford University and the Authors.      *
 * Authors: Peter Eastman                                                     *
 * Contributors:                                                              *
 *                                                                            *
 * This program is free software: you can redistribute it and/or modify       *
 * it under the terms of the GNU Lesser General Public License as published   *
 * by the Free Software Foundation, either version 3 of the License, or       *
 * (at your option) any later version.                                        *
 *                                                                            *
 * This program is distributed in the hope that it will be useful,            *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of             *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              *
 * GNU Lesser General Public License for more details.                        *
 *                                                                            *
 * You should have received a copy of the GNU Lesser General Public License   *
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.      *
 * -------------------------------------------------------------------------- */

#include <map>
#include <string>
#define CL_HPP_ENABLE_EXCEPTIONS
#define CL_HPP_TARGET_OPENCL_VERSION 120
#define CL_HPP_MINIMUM_OPENCL_VERSION 120
#ifndef CL_DEVICE_SIMD_PER_COMPUTE_UNIT_AMD
  #define CL_DEVICE_SIMD_PER_COMPUTE_UNIT_AMD 0x4040
#endif
#ifndef CL_DEVICE_SIMD_WIDTH_AMD
  #define CL_DEVICE_SIMD_WIDTH_AMD 0x4041
#endif
#ifndef CL_DEVICE_SIMD_INSTRUCTION_WIDTH_AMD
  #define CL_DEVICE_SIMD_INSTRUCTION_WIDTH_AMD 0x4042
#endif
#ifndef CL_DEVICE_WAVEFRONT_WIDTH_AMD
  #define CL_DEVICE_WAVEFRONT_WIDTH_AMD 0x4043
#endif
#ifdef _MSC_VER
    // Prevent Windows from defining macros that interfere with other code.
    #define NOMINMAX
#endif
#include "opencl.hpp"
#include "openmm/common/windowsExportCommon.h"
#include "OpenCLArray.h"
#include "OpenCLBondedUtilities.h"
#include "OpenCLExpressionUtilities.h"
#include "OpenCLIntegrationUtilities.h"
#include "OpenCLNonbondedUtilities.h"
#include "OpenCLPlatform.h"
#include "openmm/common/ComputeContext.h"

namespace OpenMM {

class OpenCLForceInfo;

/**
 * These are a few extra vector types beyond the ones in ComputeVectorTypes.h.
 */

struct mm_float8 {
    cl_float s0, s1, s2, s3, s4, s5, s6, s7;
    mm_float8() {
    }
    mm_float8(cl_float s0, cl_float s1, cl_float s2, cl_float s3, cl_float s4, cl_float s5, cl_float s6, cl_float s7) :
        s0(s0), s1(s1), s2(s2), s3(s3), s4(s4), s5(s5), s6(s6), s7(s7) {
    }
};
struct mm_float16 {
    cl_float s0, s1, s2, s3, s4, s5, s6, s7, s8, s9, s10, s11, s12, s13, s14, s15;
    mm_float16() {
    }
    mm_float16(cl_float s0, cl_float s1, cl_float s2, cl_float s3, cl_float s4, cl_float s5, cl_float s6, cl_float s7,
            cl_float s8, cl_float s9, cl_float s10, cl_float s11, cl_float s12, cl_float s13, cl_float s14, cl_float s15) :
        s0(s0), s1(s1), s2(s2), s3(s3), s4(s4), s5(s5), s6(s6), s7(s7),
        s8(s8), s9(s9), s10(s10), s11(s11), s12(s12), s13(s13), s14(s14), s15(15) {
    }
};
struct mm_ushort2 {
    cl_ushort x, y;
    mm_ushort2() {
    }
    mm_ushort2(cl_ushort x, cl_ushort y) : x(x), y(y) {
    }
};
struct mm_int8 {
    cl_int s0, s1, s2, s3, s4, s5, s6, s7;
    mm_int8() {
    }
    mm_int8(cl_int s0, cl_int s1, cl_int s2, cl_int s3, cl_int s4, cl_int s5, cl_int s6, cl_int s7) :
        s0(s0), s1(s1), s2(s2), s3(s3), s4(s4), s5(s5), s6(s6), s7(s7) {
    }
};
struct mm_int16 {
    cl_int s0, s1, s2, s3, s4, s5, s6, s7, s8, s9, s10, s11, s12, s13, s14, s15;
    mm_int16() {
    }
    mm_int16(cl_int s0, cl_int s1, cl_int s2, cl_int s3, cl_int s4, cl_int s5, cl_int s6, cl_int s7,
            cl_int s8, cl_int s9, cl_int s10, cl_int s11, cl_int s12, cl_int s13, cl_int s14, cl_int s15) :
        s0(s0), s1(s1), s2(s2), s3(s3), s4(s4), s5(s5), s6(s6), s7(s7),
        s8(s8), s9(s9), s10(s10), s11(s11), s12(s12), s13(s13), s14(s14), s15(15) {
    }
};

/**
 * This class contains the information associated with a Context by the OpenCL Platform.  Each OpenCLContext is
 * specific to a particular device, and manages data structures and kernels for that device.  When running a simulation
 * in parallel on multiple devices, there is a separate OpenCLContext for each one.  The list of all contexts is
 * stored in the OpenCLPlatform::PlatformData.
 * <p>
 * In addition, a worker thread is created for each OpenCLContext.  This is used for parallel computations, so that
 * blocking calls to one device will not block other devices.  When only a single device is being used, the worker
 * thread is not used and calculations are performed on the main application thread.
 */

class OPENMM_EXPORT_COMMON OpenCLContext : public ComputeContext {
public:
    class WorkTask;
    class ReorderListener;
    class ForcePreComputation;
    class ForcePostComputation;
    static const int ThreadBlockSize;
    static const int TileSize;
    OpenCLContext(const System& system, int platformIndex, int deviceIndex, const std::string& precision, OpenCLPlatform::PlatformData& platformData,
        OpenCLContext* originalContext);
    ~OpenCLContext();
    /**
     * This is called to initialize internal data structures after all Forces in the system
     * have been initialized.
     */
    void initialize();
    /**
     * Add an ComputeForceInfo to this context.
     */
    void addForce(ComputeForceInfo* force);
    /**
     * Request that the context provide at least a particular number of force buffers.
     * Force kernels should call this during initialization.
     */
    void requestForceBuffers(int minBuffers);
    /**
     * Get the cl::Context associated with this object.
     */
    cl::Context& getContext() {
        return context;
    }
    /**
     * Get the cl::Device associated with this object.
     */
    cl::Device& getDevice() {
        return device;
    }
    /**
     * Get the index of the cl::Device associated with this object.
     */
    int getDeviceIndex() {
        return deviceIndex;
    }
    /**
     * Get the index of the cl::Platform associated with this object.
     */
    int getPlatformIndex() {
        return platformIndex;
    }
    /**
     * Get the PlatformData object this context is part of.
     */
    OpenCLPlatform::PlatformData& getPlatformData() {
        return platformData;
    }
    /**
     * Get the number of contexts being used for the current simulation.
     * This is relevant when a simulation is parallelized across multiple devices.  In that case,
     * one OpenCLContext is created for each device.
     */
    int getNumContexts() const {
        return platformData.contexts.size();
    }
    /**
     * Get the index of this context in the list stored in the PlatformData.
     */
    int getContextIndex() const {
        return contextIndex;
    }
    /**
     * Get a list of all contexts being used for the current simulation.
     * This is relevant when a simulation is parallelized across multiple devices.  In that case,
     * one ComputeContext is created for each device.
     */
    std::vector<ComputeContext*> getAllContexts();
    /**
     * Get the ContextImpl is ComputeContext is associated with.
     */
    ContextImpl& getContextImpl() {
        return *platformData.context;
    }
    /**
     * Get a workspace used for accumulating energy when a simulation is parallelized across
     * multiple devices.
     */
    double& getEnergyWorkspace();
    /**
     * Create a new ComputeQueue for use with this context.
     */
    ComputeQueue createQueue();
    /*
     * Get the cl::CommandQueue currently being used for execution.
     */
    cl::CommandQueue getQueue();
    /**
     * Construct an uninitialized array of the appropriate class for this platform.  The returned
     * value should be created on the heap with the "new" operator.
     */
    OpenCLArray* createArray();
    /**
     * Construct a ComputeEvent object of the appropriate class for this platform.
     */
    ComputeEvent createEvent();
    /**
     * Construct a ComputeSort object of the appropriate class for this platform.
     * 
     * @param trait      a SortTrait defining the type of data to sort.  It should have been allocated
     *                   on the heap with the "new" operator.  This object takes over ownership of it,
     *                   and deletes it when the ComputeSort is deleted.
     * @param length     the length of the arrays this object will be used to sort
     * @param uniform    whether the input data is expected to follow a uniform or nonuniform
     *                   distribution.  This argument is used only as a hint.  It allows parts
     *                   of the algorithm to be tuned for faster performance on the expected
     *                   distribution.
     */
    ComputeSort createSort(ComputeSortImpl::SortTrait* trait, unsigned int length, bool uniform=true);
    /**
     * Compile source code to create a ComputeProgram.
     *
     * @param source             the source code of the program
     * @param defines            a set of preprocessor definitions (name, value) to define when compiling the program
     */
    ComputeProgram compileProgram(const std::string source, const std::map<std::string, std::string>& defines=std::map<std::string, std::string>());
    /**
     * Convert an array to an OpenCLArray.  If the argument is already an OpenCLArray, this simply casts it.
     * If the argument is a ComputeArray that wraps an OpenCLArray, this returns the wrapped array.  For any
     * other argument, this throws an exception.
     */
    OpenCLArray& unwrap(ArrayInterface& array) const;
    /**
     * Get the array which contains the position (the xyz components) and charge (the w component) of each atom.
     */
    OpenCLArray& getPosq() {
        return posq;
    }
    /**
     * Get the array which contains a correction to the position of each atom.  This only exists if getUseMixedPrecision() returns true.
     */
    OpenCLArray& getPosqCorrection() {
        return posqCorrection;
    }
    /**
     * Get the array which contains the velocity (the xyz components) and inverse mass (the w component) of each atom.
     */
    OpenCLArray& getVelm() {
        return velm;
    }
    /**
     * Get the array which contains the force on each atom.
     */
    OpenCLArray& getForce() {
        return force;
    }
    /**
     * Get the array which contains the buffers in which forces are computed.
     */
    OpenCLArray& getForceBuffers() {
        return forceBuffers;
    }
    /**
     * Get the array which contains a contribution to each force represented as a real4.
     * This is a synonym for getForce().  It exists to satisfy the ComputeContext interface.
     */
    ArrayInterface& getFloatForceBuffer() {
        return force;
    }
    /**
     * Get the array which contains a contribution to each force represented as 64 bit fixed point.
     */
    OpenCLArray& getLongForceBuffer() {
        return longForceBuffer;
    }
    /**
     * Get the array which contains the buffer in which energy is computed.
     */
    OpenCLArray& getEnergyBuffer() {
        return energyBuffer;
    }
    /**
     * Get the array which contains the buffer in which derivatives of the energy with respect to parameters are computed.
     */
    OpenCLArray& getEnergyParamDerivBuffer() {
        return energyParamDerivBuffer;
    }
    /**
     * Get a pointer to a block of pinned memory that can be used for efficient transfers between host and device.
     * This is guaranteed to be at least as large as any of the arrays returned by methods of this class.
     */
    void* getPinnedBuffer() {
        return pinnedMemory;
    }
    /**
     * Get a shared ThreadPool that code can use to parallelize operations.
     * 
     * Because this object is freely available to all code, care is needed to avoid conflicts.  Only use it
     * from the main thread, and make sure all operations are complete before you invoke any other code that
     * might make use of it
     */
    ThreadPool& getThreadPool() {
        return getPlatformData().threads;
    }
    /**
     * Get the array which contains the index of each atom.
     */
    OpenCLArray& getAtomIndexArray() {
        return atomIndexDevice;
    }
    /**
     * Create an OpenCL Program from source code.
     *
     * @param source             the source code of the program
     * @param optimizationFlags  the optimization flags to pass to the OpenCL compiler.  If this is
     *                           omitted, a default set of options will be used
     */
    cl::Program createProgram(const std::string source, const char* optimizationFlags = NULL);
    /**
     * Create an OpenCL Program from source code.
     *
     * @param source             the source code of the program
     * @param defines            a set of preprocessor definitions (name, value) to define when compiling the program
     * @param optimizationFlags  the optimization flags to pass to the OpenCL compiler.  If this is
     *                           omitted, a default set of options will be used
     */
    cl::Program createProgram(const std::string source, const std::map<std::string, std::string>& defines, const char* optimizationFlags = NULL);
    /**
     * Execute a kernel.
     *
     * @param kernel       the kernel to execute
     * @param workUnits    the maximum number of work units that should be used
     * @param blockSize    the size of each thread block to use
     */
    void executeKernel(cl::Kernel& kernel, int workUnits, int blockSize = -1);
    /**
     * Compute the largest thread block size that can be used for a kernel that requires a particular amount of
     * shared memory per thread.
     * 
     * @param memory        the number of bytes of shared memory per thread
     */
    int computeThreadBlockSize(double memory) const;
    /**
     * Set all elements of an array to 0.
     */
    void clearBuffer(ArrayInterface& array);
    /**
     * Set all elements of an array to 0.
     *
     * @param memory     the Memory to clear
     * @param size       the size of the buffer in bytes
     */
    void clearBuffer(cl::Memory& memory, int size);
    /**
     * Register a buffer that should be automatically cleared (all elements set to 0) at the start of each force or energy computation.
     */
    void addAutoclearBuffer(ArrayInterface& array);
    /**
     * Register a buffer that should be automatically cleared (all elements set to 0) at the start of each force or energy computation.
     *
     * @param memory     the Memory to clear
     * @param size       the size of the buffer in bytes
     */
    void addAutoclearBuffer(cl::Memory& memory, int size);
    /**
     * Clear all buffers that have been registered with addAutoclearBuffer().
     */
    void clearAutoclearBuffers();
    /**
     * Given a collection of floating point buffers packed into an array, sum them and store
     * the sum in the first buffer.
     * Also, write the result into a 64-bit fixed point buffer (overwriting its contents).
     *
     * @param array       the array containing the buffers to reduce
     * @param longBuffer  the 64-bit fixed point buffer to write the result into
     * @param numBuffers  the number of buffers packed into the array
     */
    void reduceBuffer(OpenCLArray& array, OpenCLArray& longBuffer, int numBuffers);
    /**
     * Sum the buffers containing forces.
     */
    void reduceForces();
    /**
     * Sum the buffer containing energy.
     */
    double reduceEnergy();
    /**
     * Get the current simulation time.
     */
    double getTime() {
        return time;
    }
    /**
     * Set the current simulation time.
     */
    void setTime(double t) {
        time = t;
    }
    /**
     * Get the number of integration steps that have been taken.
     */
    long long getStepCount() {
        return stepCount;
    }
    /**
     * Set the number of integration steps that have been taken.
     */
    void setStepCount(long long steps) {
        stepCount = steps;
    }
    /**
     * Get the number of times forces or energy has been computed.
     */
    int getComputeForceCount() {
        return computeForceCount;
    }
    /**
     * Set the number of times forces or energy has been computed.
     */
    void setComputeForceCount(int count) {
        computeForceCount = count;
    }
    /**
     * Get the number of time steps since the atoms were reordered.
     */
    int getStepsSinceReorder() const {
        return stepsSinceReorder;
    }
    /**
     * Set the number of time steps since the atoms were reordered.
     */
    void setStepsSinceReorder(int steps) {
        stepsSinceReorder = steps;
    }
    /**
     * Get the flag that marks whether the current force evaluation is valid.
     */
    bool getForcesValid() const {
        return forcesValid;
    }
    /**
     * Get the flag that marks whether the current force evaluation is valid.
     */
    void setForcesValid(bool valid) {
        forcesValid = valid;
    }
    /**
     * Get the number of blocks of TileSize atoms.
     */
    int getNumAtomBlocks() const {
        return numAtomBlocks;
    }
    /**
     * Get the standard number of thread blocks to use when executing kernels.
     */
    int getNumThreadBlocks() const {
        return numThreadBlocks;
    }
    /**
     * Get the maximum number of threads in a thread block supported by this device.
     */
    int getMaxThreadBlockSize() const {
        return device.getInfo<CL_DEVICE_MAX_WORK_GROUP_SIZE>();
    }
    /**
     * Get the number of force buffers.
     */
    int getNumForceBuffers() const {
        return numForceBuffers;
    }
    /**
     * Get whether the device being used is a CPU.  In some cases, different algorithms
     * may be more efficient on CPUs and GPUs.
     */
    bool getIsCPU() const {
        return (device.getInfo<CL_DEVICE_TYPE>() == CL_DEVICE_TYPE_CPU);
    }
    /**
     * Get the SIMD width of the device being used.
     */
    int getSIMDWidth() const {
        return simdWidth;
    }
    /**
     * Get whether the device being used supports 64 bit atomic operations on global memory.
     */
    bool getSupports64BitGlobalAtomics() const {
        return supports64BitGlobalAtomics;
    }
    /**
     * Get whether the device being used supports double precision math.
     */
    bool getSupportsDoublePrecision() const {
        return supportsDoublePrecision;
    }
    /**
     * Get whether double precision is being used.
     */
    bool getUseDoublePrecision() const {
        return useDoublePrecision;
    }
    /**
     * Get whether mixed precision is being used.
     */
    bool getUseMixedPrecision() const {
        return useMixedPrecision;
    }
    /**
     * Get whether the periodic box is triclinic.
     */
    bool getBoxIsTriclinic() const {
        return boxIsTriclinic;
    }
    /**
     * Get the vectors defining the periodic box.
     */
    void getPeriodicBoxVectors(Vec3& a, Vec3& b, Vec3& c) const {
        a = Vec3(periodicBoxVecXDouble.x, periodicBoxVecXDouble.y, periodicBoxVecXDouble.z);
        b = Vec3(periodicBoxVecYDouble.x, periodicBoxVecYDouble.y, periodicBoxVecYDouble.z);
        c = Vec3(periodicBoxVecZDouble.x, periodicBoxVecZDouble.y, periodicBoxVecZDouble.z);
    }
    /**
     * Set the vectors defining the periodic box.
     */
    void setPeriodicBoxVectors(const Vec3& a, const Vec3& b, const Vec3& c) {
        periodicBoxVecX = mm_float4((float) a[0], (float) a[1], (float) a[2], 0.0f);
        periodicBoxVecY = mm_float4((float) b[0], (float) b[1], (float) b[2], 0.0f);
        periodicBoxVecZ = mm_float4((float) c[0], (float) c[1], (float) c[2], 0.0f);
        periodicBoxVecXDouble = mm_double4(a[0], a[1], a[2], 0.0);
        periodicBoxVecYDouble = mm_double4(b[0], b[1], b[2], 0.0);
        periodicBoxVecZDouble = mm_double4(c[0], c[1], c[2], 0.0);
        periodicBoxSize = mm_float4((float) a[0], (float) b[1], (float) c[2], 0.0f);
        invPeriodicBoxSize = mm_float4(1.0f/(float) a[0], 1.0f/(float) b[1], 1.0f/(float) c[2], 0.0f);
        periodicBoxSizeDouble = mm_double4(a[0], b[1], c[2], 0.0);
        invPeriodicBoxSizeDouble = mm_double4(1.0/a[0], 1.0/b[1], 1.0/c[2], 0.0);
    }
    /**
     * Get the size of the periodic box.
     */
    mm_float4 getPeriodicBoxSize() const {
        return periodicBoxSize;
    }
    /**
     * Get the size of the periodic box.
     */
    mm_double4 getPeriodicBoxSizeDouble() const {
        return periodicBoxSizeDouble;
    }
    /**
     * Get the inverse of the size of the periodic box.
     */
    mm_float4 getInvPeriodicBoxSize() const {
        return invPeriodicBoxSize;
    }
    /**
     * Get the inverse of the size of the periodic box.
     */
    mm_double4 getInvPeriodicBoxSizeDouble() const {
        return invPeriodicBoxSizeDouble;
    }
    /**
     * Get the first periodic box vector.
     */
    mm_float4 getPeriodicBoxVecX() {
        return periodicBoxVecX;
    }
    /**
     * Get the first periodic box vector.
     */
    mm_double4 getPeriodicBoxVecXDouble() {
        return periodicBoxVecXDouble;
    }
    /**
     * Get the second periodic box vector.
     */
    mm_float4 getPeriodicBoxVecY() {
        return periodicBoxVecY;
    }
    /**
     * Get the second periodic box vector.
     */
    mm_double4 getPeriodicBoxVecYDouble() {
        return periodicBoxVecYDouble;
    }
    /**
     * Get the third periodic box vector.
     */
    mm_float4 getPeriodicBoxVecZ() {
        return periodicBoxVecZ;
    }
    /**
     * Get the third periodic box vector.
     */
    mm_double4 getPeriodicBoxVecZDouble() {
        return periodicBoxVecZDouble;
    }
    /**
     * Get the OpenCLIntegrationUtilities for this context.
     */
    OpenCLIntegrationUtilities& getIntegrationUtilities() {
        return *integration;
    }
    /**
     * Get the OpenCLExpressionUtilities for this context.
     */
    OpenCLExpressionUtilities& getExpressionUtilities() {
        return *expression;
    }
    /**
     * Get the OpenCLBondedUtilities for this context.
     */
    OpenCLBondedUtilities& getBondedUtilities() {
        return *bonded;
    }
    /**
     * Get the OpenCLNonbondedUtilities for this context.
     */
    OpenCLNonbondedUtilities& getNonbondedUtilities() {
        return *nonbonded;
    }
    /**
     * Create a new NonbondedUtilities for use with this context.  This should be called
     * only in unusual situations, when a Force needs its own NonbondedUtilities object
     * separate from the standard one.  The caller is responsible for deleting the object
     * when it is no longer needed.
     */
    OpenCLNonbondedUtilities* createNonbondedUtilities() {
        return new OpenCLNonbondedUtilities(*this);
    }
    /**
     * Create an object for performing 3D FFTs.  The caller is responsible for deleting
     * the object when it is no longer needed.
     *
     * @param xsize   the first dimension of the data sets on which FFTs will be performed
     * @param ysize   the second dimension of the data sets on which FFTs will be performed
     * @param zsize   the third dimension of the data sets on which FFTs will be performed
     * @param realToComplex  if true, a real-to-complex transform will be done.  Otherwise, it is complex-to-complex.
     */
    FFT3D createFFT(int xsize, int ysize, int zsize, bool realToComplex=false);
    /**
     * Get the smallest legal size for a dimension of the grid.
     */
    int findLegalFFTDimension(int minimum);
    /**
     * This should be called by the Integrator from its own initialize() method.
     * It ensures all contexts are fully initialized.
     */
    void initializeContexts();
    /**
     * Set the particle charges.  These are packed into the fourth element of the posq array.
     */
    void setCharges(const std::vector<double>& charges);
    /**
     * Request to use the fourth element of the posq array for storing charges.  Since only one force can
     * do that, this returns true the first time it is called, and false on all subsequent calls.
     */
    bool requestPosqCharges();
    /**
     * Get the names of all parameters with respect to which energy derivatives are computed.
     */
    const std::vector<std::string>& getEnergyParamDerivNames() const {
        return energyParamDerivNames;
    }
    /**
     * Get a workspace data structure used for accumulating the values of derivatives of the energy
     * with respect to parameters.
     */
    std::map<std::string, double>& getEnergyParamDerivWorkspace() {
        return energyParamDerivWorkspace;
    }
    /**
     * Register that the derivative of potential energy with respect to a context parameter
     * will need to be calculated.  If this is called multiple times for a single parameter,
     * it is only added to the list once.
     * 
     * @param param    the name of the parameter to add
     */
    void addEnergyParameterDerivative(const std::string& param);
    /**
     * Wait until all work that has been queued (kernel executions, asynchronous data transfers, etc.)
     * has been submitted to the device.  This does not mean it has necessarily been completed.
     * Calling this periodically may improve the responsiveness of the computer's GUI, but at the
     * expense of reduced simulation performance.
     */
    void flushQueue();
private:
    OpenCLPlatform::PlatformData& platformData;
    void printProfilingEvents();
    int deviceIndex;
    int platformIndex;
    int contextIndex;
    int numAtomBlocks;
    int numThreadBlocks;
    int numForceBuffers;
    int simdWidth;
    bool supports64BitGlobalAtomics, supportsDoublePrecision, useDoublePrecision, useMixedPrecision, boxIsTriclinic, hasAssignedPosqCharges;
    mm_float4 periodicBoxSize, invPeriodicBoxSize, periodicBoxVecX, periodicBoxVecY, periodicBoxVecZ;
    mm_double4 periodicBoxSizeDouble, invPeriodicBoxSizeDouble, periodicBoxVecXDouble, periodicBoxVecYDouble, periodicBoxVecZDouble;
    std::string defaultOptimizationOptions;
    std::map<std::string, std::string> compilationDefines;
    cl::Context context;
    cl::Device device;
    cl::Kernel clearBufferKernel;
    cl::Kernel clearTwoBuffersKernel;
    cl::Kernel clearThreeBuffersKernel;
    cl::Kernel clearFourBuffersKernel;
    cl::Kernel clearFiveBuffersKernel;
    cl::Kernel clearSixBuffersKernel;
    cl::Kernel reduceReal4Kernel;
    cl::Kernel reduceForcesKernel;
    cl::Kernel reduceEnergyKernel;
    cl::Kernel setChargesKernel;
    cl::Buffer* pinnedBuffer;
    void* pinnedMemory;
    OpenCLArray posq;
    OpenCLArray posqCorrection;
    OpenCLArray velm;
    OpenCLArray force;
    OpenCLArray forceBuffers;
    OpenCLArray longForceBuffer;
    OpenCLArray energyBuffer;
    OpenCLArray energySum;
    OpenCLArray energyParamDerivBuffer;
    OpenCLArray atomIndexDevice;
    OpenCLArray chargeBuffer;
    std::vector<std::string> energyParamDerivNames;
    std::map<std::string, double> energyParamDerivWorkspace;
    std::vector<cl::Memory*> autoclearBuffers;
    std::vector<int> autoclearBufferSizes;
    std::vector<cl::Event> profilingEvents;
    std::vector<std::string> profilingKernelNames;
    cl_ulong profileStartTime;
    OpenCLIntegrationUtilities* integration;
    OpenCLExpressionUtilities* expression;
    OpenCLBondedUtilities* bonded;
    OpenCLNonbondedUtilities* nonbonded;
};

/**
 * This class exists only for backward compatibility.  Use ComputeContext::WorkTask instead.
 */
class OPENMM_EXPORT_COMMON OpenCLContext::WorkTask : public ComputeContext::WorkTask {
};

/**
 * This class exists only for backward compatibility.  Use ComputeContext::ReorderListener instead.
 */
class OPENMM_EXPORT_COMMON OpenCLContext::ReorderListener : public ComputeContext::ReorderListener {
};

/**
 * This class exists only for backward compatibility.  Use ComputeContext::ForcePreComputation instead.
 */
class OPENMM_EXPORT_COMMON OpenCLContext::ForcePreComputation : public ComputeContext::ForcePreComputation {
};

/**
 * This class exists only for backward compatibility.  Use ComputeContext::ForcePostComputation instead.
 */
class OPENMM_EXPORT_COMMON OpenCLContext::ForcePostComputation : public ComputeContext::ForcePostComputation {
};

} // namespace OpenMM

#endif /*OPENMM_OPENCLCONTEXT_H_*/