The previous approach was crap since it left e.g. socketpair instances
lying around for GC with their underlying FD already closed, coupled
with FD number reuse, led to random madness when GC finally runs.
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.
Receiving DEL_ROUTE without a corresponding ADD_ROUTE is now legit
behaviour, so don't print an error in this case.
Don't print an error for dropped messages if the reply_to indicates the
sender doesn't care about a response (dead and no_reply)
Earlier commit moved Stream.routes attribute into a private map
belonging to RouteMonitor, to make upgrades smoother. This adds a new
accessor method to RouteMonitor.
Now rather than simply propagate DEL_ROUTE upwards towards the parent,
we broadcast it downward to any stream that ever sent a message toward
any of the routes that have just become disconnected.
When unpickling a context, arrange for there to be a single instance
representing that context, managed by the corresponding router. This
context_by_id() was already in use by parent.py, it just needs to move
down.
This to eventually reach the point where a single Context exists that
needs 'disconnect' fired on it, so all sleeping receivers are definitely
woken.
There were two problems with detection and handling of class methods as call targets in Python 3:
* Methods no longer define `im_self` -- this is now only `__self__`
* The `types` module no longer defines a `ClassType`
The universally-compatible (v2.6+) solution was to switch to using the `inspect` module -- whose interface has been stable -- and to checking the method attribute `__self__`.
(It doesn't hurt that `inspect` checks are more brief and we now no longer need the `types` module here.)
Since BasicStream.close() invokes _stop_transmit() followed by
os.close(), and KqueuePoller._stop_transmit() defers the unsubscription
until the IO loop resumes, kqueue generates an error event for the
associated FD, even though the changelist includes an unsubscription
command for the FD.
We could fix this by deferring close() until after the IO loop has run
once (simply by calling .defer()), but that generates extra wakeups for
no real reason.
Instead simply notice the error event and log it, rather than treating
it as a legitimate event.
Another approach to fixing this would be to process
_stop_receive()/_stop_transmit() eagerly, however that entails making
more syscalls.
Closes#320.
* ansible: use unicode_literals everywhere since it only needs to be
compatible back to 2.6.
* compat/collections.py: delete this entirely and rip out the parts of
functools that require it.
* Introduce serializable Kwargs dict subclass that translates keys to
Unicode on instantiation.
* enable_debug_logging() must set _v/_vv globals.
* cStringIO does not exist in 3.x.
* Treat IOLogger and LogForwarder input as latin-1.
* Avoid ResourceWarnings in first stage by explicitly closing fps.
* Fix preamble_size.py syntax errors.
This appears to be harmless, except for Python 2.6 on Linux/Travis,
where for some reason (some stdlib change?) simply opening the TTY is
insufficient.
The 'versioner.c' dodging check added in 0ef23d86 was wrong, since the
check occurred on the host machine, when the fix actually needs to apply
to the Darwin target.
Fixes ability to target OS X from a Red Hat controller, manifesting as
an error like:
D mitogen: mitogen.parent.TtyLogStream('local.2472'): 'python(mitogen:dmw@localhost.localdomain:2449): realpath couldn\'t resolve "/usr/bin/python(mitogen:dmw@localhost.localdomain:2449)"'
The "realpath couldn't resolve" error comes from versioner.c:
https://opensource.apple.com/source/perl/perl-104/versioner/versioner.c
With epoll() there is only one kernel-side object per file descriptor,
which is why _control() is such a pain. Since we merge receive/transmit
watching into that single object, we must always test the mask for both
conditions when reading results.
Kqueue isn't/doesn't appear to be like this. The identity of a Kqueue
event is keyed on (fd, filter), and we register a separate event for
both transmit and receive, so the 'elif' in KqueuePoller.poll() does not
appear to need to change.
Previously, a FD marked for read+write would not indicate writeability
until it was no longer readable.
To support detach, we must be able to preload the target with every
module it will need prior to detachment. This implements the
intermediary part of the process (i.e. the Ansible fork parent) --
receiving LOAD_MODULE/FORWARD_MODULE pairs and ensuring they reach the
child.
The GIL could be lost between the check for an empty list and popping a
socket off the list. Previously _tls_init (per its name) used per-thread
storage, hence the bug.
machinectl does not support any sensible form of pipe to the child
process, so it is necessary to bypass it when talking to a systemd
container (see systemd/systemd#8850).
This can also form the basis for issue #223, where the post-fork
namespace switching dance required to connect to the Pythonless
container will be the same.
This change blocks off 2 common scenarios where a race condition is
upgraded to a hang, when the library could internally do better.
* Since we don't know whether the receiver of a `reply_to` is expecting
a raw or pickled message, and since in the case of a raw reply, there
is no way to signal "dead" to the receiver, override the reply_to
field to explicitly mark a message as dead using a special handle.
This replaces the serialized _DEAD sentinel value with a slightly
neater interface, in the form of the reserved IS_DEAD handle, and
enables an important subsequent change: when a context cannot route a
message, it can send a generic 'dead' reply back towards the message
source, ensuring any sleeping thread is woken with ChannelError.
The use of this field could potentially be extended later on if
additional flags are needed, but for now this seems to suffice.
* Teach Router._invoke() to reply with a dead message when it receives a
message for an invalid local handle.
* Teach Router._async_route() to reply with a dead message when it
receives an unroutable message.
There is no guarantee on the ordering select() returns file descriptors.
So if, e.g. in the case of sudo_nonexistent.yml, sudo prints an error
to a single FD before exitting, there was previously no gurantee
iter_read() would read off the error before failing due to detecting
disconnect on any FD.
Now instead we keep reading while any non-disconnected FD exists.
Presently there is still no mechanism to add :attr:`tty_stream` to the
multiplexer after connection is successful, but for now it's not
expected that anything will be logged to it anyway.
Closes#148.
Now Connection.close() *must* be called in the worker, to ensure the
reference count for a context drops correctly.
Remove 'discriminator' for now, I'm not using it for testing any more
and it complicated this code.
This code is a car crash, it needs rewritten again. Ideally some/most of
this behaviour could live on services.DeduplicatingService somehow, but
I couldn't come up with a sensible design.
Benefits:
- More correct than re.sub()
- Better handling of trailing whitespace
- Recognises doc-strings regardless of quoting style
Limitations:
- Still not entirely correct
- Creates a syntax error when function/class body is only a docstring
- Doesn't handle indented docstrings yet
- Slower by 50x - 8-10 ms vs 0.2 ms for re.sub()
- Not much scope for improving this, tokenize is 100% pure Python
- Complex state machine, harder to understand
- Higher line count in parent.py
- Untested with Mitogen parent on Python 2.x and child on Python 2.x+y
No change
- Only requires Python stdlib modules
This allows context_by_id() in the master to succeed in returning a
Context with a .name matching the context's name, needed for correct
logging.
Previously this would have logged the empty string, because the master
had no mechanism to know the name of a context created by a child.
This permits graceful shutdown of individual contexts, without tearing
down everything.
Update mitogen.parent.Stream to also wait for the child to exit, to
prevent the buildup of zombie processes. This introduces a blocking wait
for process exit on the Broker thread, let's see if we can get away with
it. Chances are reasonable that it'll cause needless hangs on heavily
loaded machines.
The Context and Router APIs for constructing children and making
function calls should be available in every parent context, as user code
wants to have access to the same API.
This is a hacky layering violation, but it seems the simplest approach
for now: fork needs access to Router, in order to recover the existing
Importer instance.
* IDs are allocated by the parent responsible for contructing a new
child, using ALLOCATE_ID to the master as necessary to allocate new ID
ranges.
* ADD_ROUTE is sent up the tree rather than down. This permits
construction of the new context to complete concurrent to parent
contexts learning about its existence. Since all streams are strictly
ordered, it's not possible for any parent to observe messages from the
new context prior to arrival of an ADD_ROUTE from the parent notifying
of its existence.
If the new context, for example, implements an Ansible async task, its
parent can start executing that without waiting for any synchronous
confirmation from any parent or the master.
* Since routes propagate up, it's no longer possible for a plain
non-parent child to ever receive ADD_ROUTE, so that code can be moved
out of core.py and into parent.py (-0.2kb compressed).
* Add a .routes attribute to parent.Stream, and respond to disconnection
signal on the stream by propagating DEL_ROUTE for any ADD_ROUTE ever
received from that stream.
* Centralize route management in a new parent.RouteMonitor class
SSH command size: 439 (+4 bytes)
Preamble size: 8941 (no change)
This _increases_ the size of the first stage, but
- Eliminates one of the two remaining uses of `sys`
- Reads the preamble as a byte-string, no call `.encode()`
is needed on Python 3 before calling `_()`
SSH command size: 435 (-4 bytes)
Preamble size: 8962 (no change)
os.execl is the same as os.execv, but it take a variable number of
arguments instead of a single sequence.
SSH command size: 448 (-5 bytes)
Preamble size: 8941 (no change)
NB: The 'zip' alias was absent in Python 3.x, until Python 3.4. This
should change be reverted if Python 3.0, 3.2, or 3.3 support is
required.
David Wilson