mypy and python type hints are not powerful enough to properly describe
JSON messages in Python 3.6. The best we can do, generally, is describe
them as Dict[str, Any].
Add casts to coerce this type for static analysis; but do NOT enforce
this type at runtime in any way.
Note: Python 3.8 adds a TypedDict construct which allows for the
description of more arbitrary Dictionary shapes. There is a third-party
module, "Pydantic", which is compatible with 3.6 that can be used
instead of the JSON library that parses JSON messages to fully-typed
Python objects, and may be preferable in some cases.
(That is well beyond the scope of this commit or series.)
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200710052220.3306-6-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
This makes typing the qmp library difficult, as it necessitates wrapping
Optional[] around the type for every return type up the stack. At some
point, it becomes difficult to discern or remember why it's None instead
of the expected object.
Use the python exception system to tell us exactly why we didn't get an
object. Remove this special-cased return.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200710052220.3306-5-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
When I initially split this out, I considered this more of a machine
error than a QMP protocol error, but I think that's misguided.
Move this back to qmp.py and name it QMPResponseError. Convert
qmp.command() to use this exception type.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200710052220.3306-4-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Machine.wait() does not appear to be used except in the acceptance tests,
and an infinite timeout by default in a test suite is not the most helpful.
Change it to 3 seconds, like the default shutdown timeout.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Tested-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20200710050649.32434-13-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
This is done primarily to avoid the 'bare except' pattern, which
suppresses all exceptions during shutdown and can obscure errors.
Replace this with a pattern that isolates the different kind of shutdown
paradigms (_hard_shutdown and _soft_shutdown), and a new fallback shutdown
handler (_do_shutdown) that gracefully attempts one before the other.
This split now also ensures that no matter what happens,
_post_shutdown() is always invoked.
shutdown() changes in behavior such that if it attempts to do a graceful
shutdown and is unable to, it will now always raise an exception to
indicate this. This can be avoided by the test writer in three ways:
1. If the VM is expected to have already exited or is in the process of
exiting, wait() can be used instead of shutdown() to clean up resources
instead. This helps avoid race conditions in shutdown.
2. If a test writer is expecting graceful shutdown to fail, shutdown
should be called in a try...except block.
3. If the test writer has no interest in performing a graceful shutdown
at all, kill() can be used instead.
Handling shutdown in this way makes it much more explicit which type of
shutdown we want and allows the library to report problems with this
process.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Tested-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20200710050649.32434-11-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
If the VM is not launched, don't try to shut it down. As a change,
_post_shutdown now unconditionally also calls _early_cleanup in order to
offer comprehensive object cleanup in failure cases.
As a courtesy, treat it as a NOP instead of rejecting it as an
error. This is slightly nicer for acceptance tests where vm.shutdown()
is issued unconditionally in tearDown callbacks.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200710050649.32434-6-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Move more cleanup actions into _post_shutdown. As a change, if QEMU
should so happen to be terminated during a call to wait(), that event
will now be logged.
This is not likely to occur during normative use.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Tested-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200710050649.32434-2-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
We add the ConsoleSocket object, which has a socket interface
and which will consume all arriving characters on the
socket, placing them into an in memory buffer.
This will also provide those chars via recv() as
would a regular socket.
ConsoleSocket also has the option of dumping
the console bytes to a log file.
We also give QEMUMachine the option of using ConsoleSocket
to drain and to use for logging console to a file.
By default QEMUMachine does not use ConsoleSocket.
This is added in preparation for use by basevm.py in a later commit.
This is a workaround we found was needed for basevm.py since
there is a known issue where QEMU will hang waiting
for console characters to be consumed.
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Cleber Rosa <crosa@redhat.com>
Signed-off-by: Robert Foley <robert.foley@linaro.org>
Reviewed-by: Peter Puhov <peter.puhov@linaro.org>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200601211421.1277-9-robert.foley@linaro.org>
Message-Id: <20200701135652.1366-13-alex.bennee@linaro.org>
In truth, if you don't do this, you'll just get a TypeError
exception. Now, you'll get an AssertionError.
Is this tangibly better? No.
Does mypy complain less? Yes.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200514055403.18902-21-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
mypy considers it incorrect to use `bool` to statically return false,
because it will assume that it could conceivably return True, and gives
different analysis in that case. Use a None return to achieve the same
effect, but make mypy happy.
Note: Pylint considers function signatures as code that might trip the
duplicate-code checker. I'd rather not disable this as it does not
trigger often in practice, so I'm disabling it as a one-off and filed a
change request; see https://github.com/PyCQA/pylint/issues/3619
Signed-off-by: John Snow <jsnow@redhat.com>
Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200514055403.18902-14-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
