The Process class requires the ability to write out any processes
output to stdout, logging, or an explicit file, as well as store
it inside python for processing by test utilities. To accomplish
this each process was given a temporary file to write to, and that
file had an IO watch set on it. Any data that was written was then
read, and re-written out to where it needed to go. This ended up
being very buggy and quite complex due to needing to mess with
read/write pointers inside the file.
Popen already creates pipes to stdout if told, and they are accessable
via the p.stdout. Its then as simple as setting an IO watch on that
pipe and keeping the same code for reading out new data and writing
it to any files we want. This greatly reduces the complexity.
Occationally python will fatally terminate trying to load a test
using importlib with an out of memory exception. Increasing RAM
allows reliable exection of all tests.
When logging is enabled TLS debugging is turned on which creates
a PEM file during runtime. There is no way for IWD itself to clean
this up since its meant to be there for debugging.
Newer QEMU version warn that msize is set too low and may result
in poor IO performance. The default is 8KiB which QEMU claims is
too low. Explicitly setting to 10KiB removes the warning:
qemu-system-x86_64: warning: 9p: degraded performance: a
reasonable high msize should be chosen on client/guest side
(chosen msize is <= 8192).
See https://wiki.qemu.org/Documentation/9psetup#msize for details.
We seem to be not specifying the msize for the root filesystem, which
results in this warning being printed:
emu-system-x86_64: warning: 9p: degraded performance: a reasonable high msize should be chosen on client/guest side (chosen msize is <= 8192). See https://wiki.qemu.org/Documentation/9psetup#msize for details.
There doesn't seem to be much performance difference in the end since
iwd does not process large files.
Right now the --valgrind option logs to a static file named
'valgrind.log'. This means that for any test that run multiple
instances of iwd, output is lost for all invocations except the last.
Fix that by using a per-process log file and making sure that all log
files are printed to stdout when the test ends.
This approach isn't perfect since it is possible for the pid to be
reused, but better than the current behavior.
test-runner will print out if files were left behind after a
test which lets the developer know something was not cleaned
up. But in this case test-runner should also remove these files
so they are not left, and printed, for each subsequent test.
Certain tests like testAP spawn two IWD process in separate
namespaces. When --valrind is used this eats up quite a bit
of RAM and causes the VM to run out of memory and start
killing off processes.
Since using --valgrind actually runs IWD using the valgrind
process the --verbose flag would only work if 'valgrind' was
also specified. This was taken into account with is_verbose
but the actual logic enabling stdout did not use that helper.
This was due, in part, to logging since is_verbose will always
return true if --log is used. To fix this a new flag was added
to is_verbose which omits the --log check to handle this
specific case.
There was a bug with process output where the last bit of data would
never make it into stdout or log files. This was due to the IO watch
being cleaned up when the process was killed and never allowing it
to finish writing any pending data.
Now the IO watch implementation has been moved out into its own
function (io_process) which is now used to write the final bits of
data out on process exit.
The processes in the list ultimately get removed for each
kill() call. This causes strange behavior since the list is
being iterated and each iteration is removing items. Instead
iterate over a new temporary list so the actual process list
can be cleaned up.
IWD_GENL_DEBUG is not generally useful anymore as it just prints a
hexdump of the raw data on the socket. The messages are quite verbose
and spam test-runner logs for little utility.
Process output was being duplicated when -v was used. This was
due to both stderr and stdout being appended to the write_fd list
as well as stderr being set to stdout in the Popen call.
To fix this only stdout should be appended to the write_fd list,
but then there comes a problem with closing the streams. stdout
cannot be closed, so instead it is special cased. A new
verbose boolean was added to Process which, if True, will
cause any output to be written to stdout explicitly.
The Namespace class was never being removed when tests finished.
This is fixed by unreffing the hwsim internal _radio object which
both cleans up the radio and allows the Namespace to be removed.
This moves all the de-init code into kill(), which fixes a few
reference issues causing processes to hang around longer than
desired. If the process terminates on its own and/or the last
reference is lost __del__ will kill the process and clean up.
There were a few issues with the cleanup of Hostapd. First the
process was only being killed, which did not actually remove
the process from the list.
In addition, with EAP-SIM/AKA tests, hostapd created sim_db
unix socket files which it does not clean up.
This is somewhat of an open issue/TODO but for now this avoids
the exception caused by trying to remove a radio that has been
moved to a namespace. Once a radio is moved hwsim loses that phy
and can no longer interact with it. This causes the Destroy()
method call to fail.
A cleanup parameter was added to __init__ which can be used
by processes which create any additional files or require more
a custom cleanup routine. Some additional house keeping was
done to make Process cleanup more robust.
Though multi-test processes seemed like a good idea in terms of
efficiency, the additional code/special cases was not worth it
for the only two multi-test processes (dbus/haveged). Intead this
concept was removed completely and TestContext/Namespaces will
now start all processes for each individual test. This also is
fair to all tests as a previous failed test could end up bleeding
into future tests.
Printing out processes was done manually but instead we can
make Process printing extendable by adding its own __str__
method. This now will print if the process is a multi-test
process as well.
Output files in namespaces were not handled differently and would
end up overwriting/duplicating files from the root namespace. These
are now named /tmp/<process>-<namespace>-out.
The process class was quite hard to understand, and somewhat
fragile when multiple output options were needed like verbose
and logging, and in some cases even an additional output file.
To make things simpler we can have all processes output to a
temporary file (/tmp/<name>-out) and set a GLib IO watch on
that file. When the IO watch callback fires any additional
files (stdout, log files, output files) can be written to.
For wait=True processes we do not use an IO watch, but do
the same thing once the process exits, write to any additional
output files using the process output we already have.
The log dir was never being cleaned out prior to a new logging
test run. This could leave old stale files around. Note that this
will remove any past log files so if you need them, you want to
make a copy before running test-runner with --log again.
Dbus should be started as a multi-test process from the
TestContext, which leaves the dbus address file around for
the full test run. For Namespaces dbus-daemon should be
closed when the Namespace closes.
There were some major problems related to logging and process
output. Tests which required output from start_process would
break if used with '--log/--verbose'. This is because we relied
on 'communicate' to retrieve the process output, but Popen does
not store process output when stdout/stderr are anything other
than PIPE.
Intead, in the case of logging or outfiles, we can simply read
from the file we just wrote to.
For an explicit --verbose application we must handle things
slightly different. A keyword argument was added to Process,
'need_out' which will ensure the process output is kept
regardless of --log or --verbose.
Now a user should be able to use --log/--verbose without any
tests failing.
The verbose arguments come in from the QEMU command line as a
single string. This should have been split into an array immediately
but was not. This led to issues like hostapd debug being enabled
when "-v hostapd_cli" was passed in.
Since the list of files copied to /tmp was part of the return value from
pre_test(), if an exception occurred inside pre_test(), "copied" would
be undefined and the post_test(ctx, copied) call in the finally clause
cause another exception:
raceback (most recent call last):
File "/home/balrog/repos/iwd/tools/test-runner", line 1508, in <module>
run_tests()
File "/home/balrog/repos/iwd/tools/test-runner", line 1242, in run_tests
run_auto_tests(config.ctx, args)
File "/home/balrog/repos/iwd/tools/test-runner", line 1166, in run_auto_tests
post_test(ctx, copied)
UnboundLocalError: local variable 'copied' referenced before assignment
(apart from not being able to clean up the files). Pass "copied" as a
paremeter to pre_test instead.
Use the hwsim DBus API rather than command line. This both is
faster and more dynamic than doing so with the command line.
This also avoids tracking the radio ID since we can just hang
on to the radio Dbus object directly.
The Create() API was limited to only taking a Name and boolean
(for p2p enabling). The actual hwsim nl80211 API can take more
attributes than this (which are actually utilized when creating
from the command line). To get the DBus API up to the same
functionality the two arguments in Create were replaced with
a single dictionary. This allows for extending later if more
arguments are needed.
James Prestwood