Assuming a single threaded application. If you call ExecuteCommandLists twice (A and B). Is A guaranteed to execute all of its commands on the GPU before starting any of the commands from B? The closest thing I can find in the documentation is this, but it doesn't really seem to guarantee A finishes before B starts:
Applications can submit command lists to any command queue from multiple threads. The runtime will perform the work of serializing these requests in the order of submission.
As a point of comparison, I know that this is explicitly not guarenteed in Vulkan:
vkQueueSubmit is a queue submission command, with each batch defined by an element of pSubmits as an instance of the VkSubmitInfo structure. Batches begin execution in the order they appear in pSubmits, but may complete out of order.
However, I'm not sure if DX12 works the same way.
Frank Luna's book says:
The command lists are executed in order starting with the first array element
However in that context he's talking about calling ExecuteCommandLists once with two command lists (C and D). Do these operate the same as two individual calls? My colleague argues that this still only guarantees that they are started in order, not that C finishes before D starts.
Is there more clear documentation somewhere I'm missing?