A thing to care about when passing a struct to a CUDA kernel

Structures can be passed by values to CUDA kernels. However, some care should be devoted to set up a proper destructor since the destructor is called at exit from the kernel.

Consider this example with the uncommented destructor and do not pay too much attention on what the code actually does. If you run that code, you will receive the following output:

Calling destructor

Counting in the locked case: 512

Calling destructor

GPUassert: invalid device pointer D:/Project/passStructToKernel/passClassToKernel/Utilities.cu 37

As you can see, there are two calls to the destructor, once at the kernel exit and once at the main exit.

The error message is related to the fact that, if the memory locations pointed to by d_state are freed at the kernel exit, they cannot be freed anymore at the main exit.

Accordingly, the destructor must be different for host and device executions. This is accomplished by the commented destructor in the above code.

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