bfs_kernel.cu

#ifndef _KERNEL_H
#define _KERNEL_H
typedef struct Node {
    int starting;
    int no_of_edges;
}Node;
__global__ void
test(Node* d_graph_nodes, int no_of_nodes) {
    int tid = blockIdx.x * blockDim.x + threadIdx.x;
    if (tid < no_of_nodes) {
        d_graph_nodes[tid].starting+=1;
    }
}

__global__ void
test1(bool* d_graph_visited, int no_of_nodes) {
    int tid = blockIdx.x * blockDim.x + threadIdx.x;
    if (tid < no_of_nodes) {
        d_graph_visited[tid] = true;
    }
}

__global__ void
bfs_kernel(Node* d_graph_nodes, int* d_edge_list, bool* d_graph_level,
        bool* d_graph_visited, int* d_cost, bool* loop, int no_of_nodes) {
    int tid = blockIdx.x * blockDim.x + threadIdx.x;
    //d_graph_level[tid] is true means the vertex in the current level
    //is being visited
    if (tid < no_of_nodes && d_graph_level[tid]) {
        d_graph_level[tid] = false;
        d_graph_visited[tid] = true;
        for (int i = d_graph_nodes[tid].starting; i <
                (d_graph_nodes[tid].no_of_edges +
                 d_graph_nodes[tid].starting); i++) {
            int id = d_edge_list[i];
            if (!d_graph_visited[id]) {
                //calculate in which level the vertex is visited
                d_cost[id] = d_cost[tid] + 1;
                d_graph_level[id] = true;
                //to make the loop continues
                *loop = true;
            }
        }
    }
}

#endif