Our `LockTransaction` class was reading overly aggressively. In cases
like this:
```
1 with spack.store.db.read_transaction():
2 with spack.store.db.write_transaction():
3 ...
```
The `ReadTransaction` on line 1 would read in the DB, but the
WriteTransaction on line 2 would read in the DB *again*, even though we
had a read lock the whole time. `WriteTransaction`s were only
considering nested writes to decide when to read, but they didn't know
when we already had a read lock.
- [x] `Lock.acquire_write()` return `False` in cases where we already had
a read lock.
If a write transaction was nested inside a read transaction, it would not
write properly on release, e.g., in a sequence like this, inside our
`LockTransaction` class:
```
1 with spack.store.db.read_transaction():
2 with spack.store.db.write_transaction():
3 ...
4 with spack.store.db.read_transaction():
...
```
The WriteTransaction on line 2 had no way of knowing that its
`__exit__()` call was the last *write* in the nesting, and it would skip
calling its write function.
The `__exit__()` call of the `ReadTransaction` on line 1 wouldn't know
how to write, and the file would never be written.
The DB would be correct in memory, but the `ReadTransaction` on line 4
would re-read the whole DB assuming that other processes may have
modified it. Since the DB was never written, we got stale data.
- [x] Make `Lock.release_write()` return `True` whenever we release the
*last write* in a nest.
Lock transactions were actually writing *after* the lock was
released. The code was looking at the result of `release_write()` before
writing, then writing based on whether the lock was released. This is
pretty obviously wrong.
- [x] Refactor `Lock` so that a release function can be passed to the
`Lock` and called *only* when a lock is really released.
- [x] Refactor `LockTransaction` classes to use the release function
instead of checking the return value of `release_read()` / `release_write()`
`ViewDescriptor.regenerate()` checks repeatedly whether packages are
installed and also does a lot of DB queries. Put a read transaction
around the whole thing to avoid repeatedly locking and unlocking the DB.
Users can now list mirrors of the main url in packages.
- [x] Instead of just a single `url` attribute, users can provide a list (`urls`) in the package, and these will be tried by in order by the fetch strategy.
- [x] To handle one of the most common mirror cases, define a `GNUMirrorPackage` mixin to handle all the standard GNU mirrors. GNU packages can set `gnu_mirror_path` to define the path within a mirror, and the mixin handles setting up all the requisite GNU mirror URLs.
- [x] update all GNU packages in `builtin` to use the `GNUMirrorPackage` mixin.
* Add symbols patch
* Apply symbols patch to pgmath
* Add github issue number for symbols patch.
* Add naromero77 as a maintainer.
* Patch only applied to March 2019 release and master.
* Record that old versions of ROOT don't support modern GCC
* Well, actually I don't know about 6.07
* Fix typo and follow odd version recommendation from @chissg
* Add QE 6.5
* Support for serial HDF5 case with serial (no mpi) QE is now supported but requires a patch for 6.4.1 and 6.5.
* Add naromero77 as a maintainer.
* Start cinema package
* Remove boilerplate and add description
* Formatting for pep8
* Correct milestone tag
* 'master' instead of 'develop'
Co-Authored-By: Adam J. Stewart <ajstewart426@gmail.com>
* Two variants, both with numpy and other small changes
* When +image for scikit
Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>
- Add an optional argument so that `possible_dependencies()` will report
missing dependencies.
- Add a test to ensure it works.
- Ignore missing dependencies in `possible_dependencies()` by default.
- this version allows getting possible dependencies of multiple packages
or specs at once.
- New method handles calling `PackageBase.possible_dependencies` multiple
times and passing `visited` dict around.
`Environment.added_specs()` has a loop around calls to
`Package.installed()`, which can result in repeated DB queries. Optimize
this with a read transaction in `Environment`.
Checks for deprecated specs were repeatedly taking out read locks on the
database, which can be very slow.
- [x] put a read transaction around the deprecation check
