ret = cl.clReleaseCommandQueue(commandQueue);
checkError("on clReleaseCommandQueue", ret);
ret = cl.clReleaseMemObject(devSrcA);
checkError("on clReleaseMemObject", ret);
ret = cl.clReleaseMemObject(devSrcB);
checkError("on clReleaseMemObject", ret);
ret = cl.clReleaseMemObject(devDst);
checkError("on clReleaseMemObject", ret);
ret = cl.clReleaseProgram(program);