Intermediate PR in removing path_info from our code base.
It is completely removed from the main codebase and is still
being used in tests, which will be migrated in the followups.
For fs-specific simple path manipulation, we've introduced
`fs.path` helper (similar to `os.path`).
Fixes#6774
* drop python 3.5 support
* dvc: remove fspath() use inside os.path calls
* dvc: replace dvc.compat.fspath with os.fspath
* tests: replace dvc.compat.fspath with os.fspath
* utils: relpath() should use fspath/str
* utils: os.readlink doesn't support path-like obj on Windows until 3.8
Currently only one instance of dvc could run in a particular repo
because of the `.dvc/lock`. That gets furstrating when you are running
some long-running command and blocked from doing anything else.
This PR solved that issue for `dvc run` by releasing the repo lock
while running the command. To protect against conflicts, we now use
rwlock, which keeps the list of readers and writers for particular
paths. The process looks like this:
1) aquire read locks for deps;
2) aquire write locks for outs;
3) release repo lock;
4) run cmd;
5) aquire repo lock;
6) release write locks for outs;
7) release read locks for outs;
We also take rwlocks for operations such as `import`, `add` and `checkout`
to ensure that we won't hit the same files that are being used by
another `dvc run` in the background.
We don't aquire rwlocks for the stage file itself, as we don't really
care about anyone overwriting a stage file, as there is a very little
difference here between parallel runs and sequential runs that overwrite
the same stage file.
Next steps might be to release repo lock on `import`(when dowloading
stuff) and when computing checksums or copying files.
Fixes#755
karajan1001
Ivan Shcheklein
Ruslan Kuprieiev
Batuhan Taskaya
Peter Rowlands (변기호)
Casper da Costa-Luis
Alexander Schepanovski
Mr. Outis