Python API for Vitals (#53238)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53238
There is a tension for the Vitals design: (1) we want a macro based logging API for C++ and (2) we want a clean python API. Furthermore, we want to this to work with "print on destruction" semantics.
The unfortunate resolution is that there are (2) ways to define vitals:
(1) Use the macros for local use only within C++ - this keeps the semantics people enjoy
(2) For vitals to be used through either C++ or Python, we use a global VitalsAPI object.
Both these go to the same place for the user: printing to stdout as the globals are destructed.
The long history on this diff shows many different ways to try to avoid having 2 different paths... we tried weak pointers & shared pointers, verbose switch cases, etc. Ultimately each ran into an ugly trade-off and this cuts the difference better the alternatives.
Test Plan:
buck test mode/dev caffe2/test:torch -- --regex vital
buck test //caffe2/aten:vitals
Reviewed By: orionr
Differential Revision: D26736443
fbshipit-source-id: ccab464224913edd07c1e8532093f673cdcb789f
