The 'extra' argument is not always used by custom logger adapters. For
example:
```python
class IndentAdapter(logging.LoggerAdapter):
def process(self, msg, kwargs):
indent = kwargs.pop(indent, 1)
return ' ' * indent + msg, kwargs
```
It is cleaner and friendlier to default the 'extra' argument to None
instead of either forcing the subclasses of LoggerAdapter to pass a None
value directly or to override the constructor.
This change is backward compatible because existing calls to
`LoggerAdapter.__init__` are already passing a value for the second
argument.
Automerge-Triggered-By: @vsajip
Fix a hang at fork in the logging module: the new private
_at_fork_reinit() method is now used to reinitialize locks at fork in
the child process.
The createLock() method is no longer used at fork.
* bpo-37742: Return the root logger when logging.getLogger('root') is called.
* Added type check guard on logger name in logging.getLogger() and refined a test.
Instead of attempting to acquire and release them all across fork
which was leading to deadlocks in some applications that had chained
their own handlers while holding multiple locks.
bpo-6721: When os.fork() was called while another thread holds a logging lock, the child process may deadlock when it tries to log. This fixes that by acquiring all logging locks before fork and releasing them afterwards.
A regression test that fails before this change is included.
Within the new unittest itself: There is a small _potential_ due to mixing of fork and a thread in the child process if the parent's thread happened to hold a non-reentrant library call lock (malloc?) when the os.fork() happens. buildbots and time will tell if this actually manifests itself in this test or not. :/ A functionality test that avoids that would be a challenge.
An alternate test that isn't trying to produce the deadlock itself but just checking that the release and acquire calls are made would be the next best alternative if so.
A check has been added in Logger.isEnabledFor() to return False when the logger is disabled. This avoids unnecessary work being done when a disabled logger is used.
This used to be the case on Python 2. Commit
212b590e11 changed the implementation for Python
3, making the `log()` method of LogAdapter call `logger._log()` directly. This
makes nested log adapters not execute their ``process()`` method. This patch
fixes the issue.
Also, now proxying `name`, too, to make `repr()` work with nested log adapters.
New tests added.
Some of the proxied methods use internal Logger state which isn't proxied,
causing failures if an adapter is applied to another adapter.
This commit fixes the issue, adds a new test for the use case.
Rémi Lapeyre
Arturo Escaip
Mariusz Felisiak
Victor Stinner
Derek Brown
Vinay Sajip
Riccardo Magliocchetti
Gregory P. Smith
Serhiy Storchaka
Rémi Lapeyre
Josh Snyder
BNMetrics
Dong-hee Na
Timo Furrer
Łukasz Langa
Antoine Pitrou
Avram Lubkin
Georg Brandl
Martin Panter