How to assert in kernel code?

Accelerated Computing CUDA CUDA Programming and Performance
1

What is the equivalent technique of an assertion in CUDA kernel code?

There does not seem to be an assert for CUDA kernel code. I want a way to catch programmer mistakes easily in kernel code. A mechanism where I can set conditions that need to be true and the kernel should bail out when the condition is false with an error message.

2

You can do assert as usual, for example

#include <stdio.h>

#define  assert( X ) if ( !(X) ) \

    printf("tid %d: %s, %d\n", threadIdx.x, __FILE__, __LINE__);\

    return ;

__global__ void foo(int *data )

{

    int tid = threadIdx.x ;

assert ( tid >= 5 ) ;

}

int main(int argc, char *argv[])

{

foo<<<1,256 >>>(NULL);

cudaThreadExit();

}

result is

tid 0: main.cu, 12

tid 1: main.cu, 12

tid 2: main.cu, 12

tid 3: main.cu, 12

tid 4: main.cu, 12

However when assertion fails, not all threads terminate. If you have some synchronization issue,

then program may hang.

3

Thanks so much, this is perfect! External Image