This introduces a new `CacheLocker` which manages locks on the package
cache. Instead of either being "locked" or "not locked", the new locker
supports multiple modes:
- Shared lock: Cargo can read from the package sources, along with any
other cargos reading at the same time.
- Download exclusive lock: Only one cargo can perform downloads.
Download locks do not interfere with Shared locks, since it is
expected that downloading does not modify existing files (only adds
new ones).
- Mutate exclusive lock: Only one cargo can have this lock, and it also
prevents shared locks. This is so that the cargo can modify the
package cache (such as deleting files) without breaking concurrent
processes.
Improve integration of the http server introduced by the http-registry feature.
Now the same HTTP server is used for serving downloads, the index, and
the API.
This makes it easier to write tests that deal with authentication and
http registries.
updating, registries now update as needed. To force a registry to
ensure the latest copy of crate metadata is available, a new method
called `invalidate_cache` is added. This method will cause the registry
to update the next time `block_until_ready` is called.
We had a few locations where the shell was written to raw instead of
through the test harness or through other captured mechanisms. This
updates the test suite so testing Cargo with `--quiet` provides a nice
and clean report of tests executed.
This commit updates the locking strategy in Cargo handle the recent
addition of creating a cache of the on-disk index also on disk. The goal
here is reduce the overhead of locking both cognitively when reading but
also performance wise by requiring fewer locks. Previously Cargo had a
bunch of fine-grained locks throughout the index and git repositories,
but after this commit there's just one global "package cache" lock.
This global lock now serves to basically synchronize the entire crate
graph resolution step. This shouldn't really take that long unless it's
downloading, in which case there's not a ton of benefit to running in
parallel anyway. The other intention of this single global lock is to
make it much easier on the sources to not worry so much about lock
ordering or when to acquire locks, but rather they just assert in their
various operations that they're locked.
Cargo now has a few coarse-grained locations where locks are held (for
example during resolution and during package downloading). These locks
are a bit sprinkled about but they have in-code asserts which assert
that they're held, so we'll find bugs quickly if any lock isn't held
(before a race condition is hit that is)
This change ensures cargo will output file paths in the expected format
(C:\foo\... on Windows, /foo/... elsewhere). Previously it would output
file:// URLs instead.
To support this change, additional changes were made to the test suite
string processing such that [ROOT] is now replaced with the appropriate
file path root for the platform.
The CWD template was also updated to use [CWD] like other replacement
templates and to do the replacement on the expected value rather than
the actual value to avoid replacing things we don't expect with CWD.
* Collapse the nested cargotest::support module into the cargotest
module (merge the mod.rs's)
* Rename the cargotest module to support
* Nest the top-level hamcrest module into support
