cuda-samples/Samples/5_Domain_Specific/simpleVulkanMMAP/MonteCarloPi.h

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#pragma once
#ifndef __PISIM_H__
#define __PISIM_H__

#include <cuda.h>
#include <cuda_runtime_api.h>
#include <curand.h>
#include <curand_kernel.h>
#include <vector>

#include "helper_multiprocess.h"

typedef float vec2[2];

class MonteCarloPiSimulation
{
    size_t m_numPoints;

    // Pointers to Cuda allocated buffers which are imported and used by vulkan as
    // vertex buffer
    vec2  *m_xyVector;
    float *m_pointsInsideCircle;

    // Pointers to device and host allocated memories storing number of points
    // that are inside the unit circle
    float *m_numPointsInCircle;
    float *m_hostNumPointsInCircle;

    int m_blocks, m_threads;

    // Total size of allocations created by cuMemMap Apis. This size is the sum of
    // sizes of m_xyVector and m_pointsInsideCircle buffers.
    size_t m_totalAllocationSize;

    // Shareable Handles(a file descriptor on Linux and NT Handle on Windows),
    // used for sharing cuda
    // allocated memory with Vulkan
    ShareableHandle m_posShareableHandle, m_inCircleShareableHandle;

    // Cuda Device corresponding to the Vulkan Physical device
    int m_cudaDevice;

    // Track and accumulate total points that have been simulated since start of
    // the sample. The idea is to get a closer approximation to PI with time.
    size_t m_totalPointsInsideCircle;
    size_t m_totalPointsSimulated;

    void setupSimulationAllocations();
    void cleanupSimulationAllocations();
    void getIdealExecutionConfiguration();

public:
    MonteCarloPiSimulation(size_t num_points);
    ~MonteCarloPiSimulation();
    void        initSimulation(int cudaDevice, cudaStream_t stream = 0);
    void        stepSimulation(float time, cudaStream_t stream = 0);
    static void computePiCallback(void *args);

    size_t getNumPoints() const { return m_numPoints; }

    float getNumPointsInCircle() const { return *m_hostNumPointsInCircle; }

    ShareableHandle &getPositionShareableHandle() { return m_posShareableHandle; }
    ShareableHandle &getInCircleShareableHandle() { return m_inCircleShareableHandle; }
};

#endif // __PISIM_H__