For join_thread():
Exception in thread mitogen.master.join_thread_async:
Traceback (most recent call last):
File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
self.run()
File "/usr/lib/python2.7/threading.py", line 754, in run
self.__target(*self.__args, **self.__kwargs)
File "/home/dmw/src/mitogen/mitogen/master.py", line 249, in _watch
watcher.on_join()
File "/home/dmw/src/mitogen/mitogen/master.py", line 816, in shutdown
super(Broker, self).shutdown()
File "/home/dmw/src/mitogen/mitogen/core.py", line 2741, in shutdown
self.defer(_shutdown)
File "/home/dmw/src/mitogen/mitogen/core.py", line 2142, in defer
raise Error(self.broker_shutdown_msg)
Error: An attempt was made to enqueue a message with a Broker that has already exitted. It is likely your program called Broker.shutdown() too early.
Allow messages to continue being queued during the shutdown period,
right up until the final loop iteration, even though this is racy, as
too many things depend on .defer() during exit right now.
This doesn't hurt the spirit of the check: it still catches the worst
situation where $user accidentally shut down Broker then tried to
continue using it.
Python at some point (at least since https://bugs.python.org/issue14605)
began populating sys.meta_path with its internal importer classes,
meaning that interpreters no longer start with an empty sys.meta_path.
Ideally it would only be called once, and in future maybe it can, but
right now we need to cope with these cases:
* Downstream parent notifies us of disconnection (DEL_ROUTE)
* We notify ourself of disconnection
* We notify ourself and so does downstream parent
It's case 3 that causes the error.
Using _lock we can know for certain whether the Broker has received a
wakeup byte yet. If it has, we can skip the wasted system call.
Now on_receive() can exactly read the single byte that can possibly
exist (modulo FD sharing bugs -- this could be improved on later)
Now poller is start enough to know a start_receive() during an iteration
does not cause events yielded by that iteration to associate with the
wrong descriptor.
These changes are tangentially related to the associated ticket, but
event versioning is still the underlying issue.
David Wilson