supporting mapAsync, getMappedRange, unmap

[greggman]

How should we go about supporting mapAsync etc?

[Kangz]

The thought was of doing the mapping in the tracer and on unmap (of a map write) record an "update data range" command. On the replay, mappable buffers would be faked and this would turn into a WriteBuffer.

[greggman]

Right, but where does the command go? Is it a device command, a queue command, an encoder command? It wasn't clear to me since they happen out of band. I looked at the spec's time line stuff and I guess unmap is effectively a device command?

[Kangz]

Essentially, same for "update data range" which would be a device command.

[greggman]

Some peeps wanted to try to use the debugger on a cts test but when I tried it that was the one feature that was missing.

I just tried hacking it myself. Since unmap is already there and it seems effectively you don't have to record mapAsync but when I did it it wasn't enough. I was just trying to run the existing basic-spinning-cube.html example and it doesn't even use mapAsync, it uses mappedAtCreation: true but it failed. I didn't look into why. Maybe it's simple. Maybe I'll find more time to spend on it too but I thought maybe it's obvious to you?