Summary:
This diff split ThreadPool to
-ThreadPool (abstract interface exposed in include/rocksdb/threadpool.h)
-ThreadPoolImpl (actual implementation in util/threadpool_imp.h)
This allow us to expose ThreadPool to the user so we can use it as an option later
Test Plan: existing unit tests
Reviewers: andrewkr, yiwu, yhchiang, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D62085
For ease of reuse and customization as a library
without wrapping.
WinEnvThreads is a class for replacement.
WintEnvIO is a class for reuse and behavior override.
Added private virtual functions for custom override
of fallocate pread for io classes.
