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#include <stdio.h>
#include "Utilities.cuh"
#define NUMBLOCKS 512
#define NUMTHREADS 512 * 2
/***************/
/* TEST STRUCT */
/***************/
struct Lock {
int *d_state;
// --- Constructor
Lock(void) {
int h_state = 0; // --- Host side lock state initializer
gpuErrchk(cudaMalloc((void **)&d_state, sizeof(int))); // --- Allocate device side lock state
gpuErrchk(cudaMemcpy(d_state, &h_state, sizeof(int), cudaMemcpyHostToDevice)); // --- Initialize device side lock state
}
// --- Destructor (wrong version)
~Lock(void) {
printf("Calling destructor\n");
gpuErrchk(cudaFree(d_state));
}
// --- Destructor (correct version)
// __host__ __device__ ~Lock(void) {
//#if !defined(__CUDACC__)
// gpuErrchk(cudaFree(d_state));
//#else
//
//#endif
// }
// --- Lock function
__device__ void lock(void) { while (atomicCAS(d_state, 0, 1) != 0); }
// --- Unlock function
__device__ void unlock(void) { atomicExch(d_state, 0); }
};
/**********************************/
/* BLOCK COUNTER KERNEL WITH LOCK */
/**********************************/
__global__ void blockCounterLocked(Lock lock, int *nblocks) {
if (threadIdx.x == 0) {
lock.lock();
*nblocks = *nblocks + 1;
lock.unlock();
}
}
/********/
/* MAIN */
/********/
int main(){
int h_counting, *d_counting;
Lock lock;
gpuErrchk(cudaMalloc(&d_counting, sizeof(int)));
// --- Locked case
h_counting = 0;
gpuErrchk(cudaMemcpy(d_counting, &h_counting, sizeof(int), cudaMemcpyHostToDevice));
blockCounterLocked << <NUMBLOCKS, NUMTHREADS >> >(lock, d_counting);
//blockCounterLocked << <NUMBLOCKS, NUMTHREADS >> >(lock);
gpuErrchk(cudaPeekAtLastError());
gpuErrchk(cudaDeviceSynchronize());
gpuErrchk(cudaMemcpy(&h_counting, d_counting, sizeof(int), cudaMemcpyDeviceToHost));
printf("Counting in the locked case: %i\n", h_counting);
gpuErrchk(cudaFree(d_counting));
}