[Profiler] Address issues from profiler bifurcation. (#70327)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70327
After D32678163 (https://github.com/pytorch/pytorch/commit/7ea86dfdb162758c9fbbf6807ab1dd778591c062), test_rpc_profiler began failing. This was surprising, because it should have been a no-op refactor. However, one change is that a Kineto profiler is no longer also an autograd profiler; the RPC framework was assuming a legacy profiler but when a kineto profiler was active things still kind of worked due to that implementation detail. (But crashed after the class split.)
This diff tidys up a couple of things:
1) Move `getProfilerConfig` into `api.cpp`, since it is no longer correct to static_cast a `KinetoThreadLocalState` to a `ProfilerLegacyThreadLocalState`. (And really the class we want is `ProfilerThreadLocalStateBase` anyway.)
2) Add a mechanism for callers to check if the active profiler is a legacy or kineto profiler. (So callers like RPC can adjust or provide a nice error message.)
3) Fix the RPC test to create a legacy profiler.
Test Plan: `caffe2/torch/fb/training_toolkit/backend/tests:test_rpc_profiler` now passes, and before the fix to `test_rpc_profiler.py`, I verified that the test failed with the error message added to `utils.cpp` rather than just crashing.
Reviewed By: suphoff
Differential Revision: D33283314
fbshipit-source-id: e4fc5b5cfc9ca3b91b8f5e09adea36f38611f90d
