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/**
 * \file
 * cub::GridBarrier implements a software global barrier among thread blocks within a CUDA grid
 */

#pragma once

#include "../util_debug.cuh"
#include "../util_namespace.cuh"
#include "../thread/thread_load.cuh"

/// Optional outer namespace(s)
CUB_NS_PREFIX

/// CUB namespace
namespace cub {


/**
 * \addtogroup GridModule
 * @{
 */


/**
 * \brief GridBarrier implements a software global barrier among thread blocks within a CUDA grid
 */
class GridBarrier
{
protected :

    typedef unsigned int SyncFlag;

    // Counters in global device memory
    SyncFlag* d_sync;

public:

    /**
     * Constructor
     */
    GridBarrier() : d_sync(NULL) {}


    /**
     * Synchronize
     */
    __device__ __forceinline__ void Sync() const
    {
        volatile SyncFlag *d_vol_sync = d_sync;

        // Threadfence and syncthreads to make sure global writes are visible before
        // thread-0 reports in with its sync counter
        __threadfence();
        CTA_SYNC();

        if (blockIdx.x == 0)
        {
            // Report in ourselves
            if (threadIdx.x == 0)
            {
                d_vol_sync[blockIdx.x] = 1;
            }

            CTA_SYNC();

            // Wait for everyone else to report in
            for (int peer_block = threadIdx.x; peer_block < gridDim.x; peer_block += blockDim.x)