Why are all my buffers zeroed?

[TirushOne]

I have a compute shader I am trying to get to take a list of (index, data) pairs and write the data at the given index into a larger buffer, allowing for sparse updates to the larger buffer. The code in the shader looks like this:

let index = global_index.x;
let write_index = update_indicies[index];
generation[write_index] += 1;
if index < arrayLength(&new_data_buf) {
let new_data = new_data_buf[index];
storage_buf[write_index] = new_data;
}

I am also using generational indicies so data that is update is marked as such and any handles pointing to that data do not access the wrong thing. The new_data_buf is always shorter then the or equal to the length of the update_indicies.

Here is the problem, whenever I run my code and that shader when I readback "generation" and "storage_buf", they both come back competley zeroed. This makes me think there is a dynamic error occuring in the shader, but I am stumped as to what it could be.

Here is what I have ruled out:

• update_indicies containing overlapping indicies and thus causing a data race.
• update_indicies containing out of bounds indicies.
• unbounded loops - my shader contains no loops.
• memory layout mismatch - all the buffers contain simple types, either arrays of floats, or ints, and I have double checked the alignment and size requirments for these and double checked my cpu-side memory representations.

Any help is greatley appreciated.