Summary:
On Windows, select cannot be used for pipes, and thus the doublepipe class
would end up busy spinning trying to read from it. Since stderr is almost
always empty let's move it to a background thread so the main code path
doesn't have to deal with it.
This proves to be a significant win for `hg pull`. For an empty manifest
cache, `hg pull` used to take ~5 minutes, it's now around 1 minute, with
Mononoke taking 40 seconds out of that.
Reviewed By: DurhamG
Differential Revision: D19352144
fbshipit-source-id: 77112c1c18d7dab15f6946a645f73e89908802f2
Summary:
In preparation for merging fb-mercurial sources to the Eden repository,
move everything from the top-level directory into an `eden/scm`
subdirectory.