Merge ~alanec/plainbox-provider-checkbox:cpufreq_test-excp-fix into plainbox-provider-checkbox:master

[Adrian Lane]

Minor fixup of exception handling class in bin/cpufreq_test.py. This fix will allow this class to now behave as fully intended, exiting cleanly without traceback if cpufreq scaling is non-supported.
Additionally warnings (logging.warning) are now visible in all modes, included quiet, as quiet is the default operating mode in Checkbox.

Sample output to demo if scaling via cpufreq is unsupported:

z3r0@maas ~ ❯❯❯ python3 test.py
## Warning: scaling via CpuFreq non-supported ##
z3r0@maas ~ ❯❯❯ python3 test.py -q
## Warning: scaling via CpuFreq non-supported ##
z3r0@maas ~ ❯❯❯ python3 test.py -d
## Warning: scaling via CpuFreq non-supported ##
z3r0@maas ~ ❯❯❯ python3 test.py -r
## Warning: scaling via CpuFreq non-supported ##

[Adrian Lane (alanec)]

Above demo performed on a VM.

[Jonathan Cave (jocave)]

I would personally prefer the test to be skipped if scaling is not supported rather than the test run and result in a pass.

review: Abstain

[Jeff Lane  (bladernr)]

Lets file a new bug to address Jonathan's concern. I don't disagree, but that would be out of scope for fixing this particular bug.

SO, Approve for this with the following conditions:

1: File a new bug to add a new resource job to create something like cpufreq.supported
2: Add an arg to the cpufreq script so that we can simply check that it is supported and if so, set cpufreq.supported to True.
3: modify the test job in P-P-C to require that resource == True.

review: Approve

[Jonathan Cave (jocave)]

Happy with that course of action, thanks

[Adrian Lane (alanec)]

This sounds good to me as well. I'll start working on adding this functionality next week.
Thanks-

diff --git a/bin/cpufreq_test.py b/bin/cpufreq_test.py
index 81ee276..ec3cf6c 100755
--- a/bin/cpufreq_test.py
+++ b/bin/cpufreq_test.py
@@ -40,9 +40,11 @@ class CpuFreqTestError(Exception):
     """Exception handling."""
     def __init__(self, message):
         super().__init__()
+        # warn and exit if cpufreq scaling non-supported
         if 'scaling_driver' in message:
-            logging.error(
-                '%s\n## Fatal: scaling via cpufeq unsupported ##')
+            logging.warning(
+                '## Warning: scaling via CpuFreq non-supported ##')
+            sys.exit()
         # exempt systems unable to change intel_pstate driver mode
         elif 'intel_pstate/status' in message:
             pass
@@ -675,6 +677,8 @@ class CpuFreqCoreTest(CpuFreqTest):
         for idx, freq in enumerate(self.scaling_freqs):
             # re-init some attributes after 1st pass
             if idx:
+                # time buffer ensure all prior freq intervals processed
+                time.sleep(1)
                 # reset freq list
                 self.__observed_freqs = []
                 # reset signal.signal() event loop bit
@@ -685,7 +689,7 @@ class CpuFreqCoreTest(CpuFreqTest):
             load_observe_map(freq)
 
 
-def parse_args_logging():
+def parse_arg_logging():
     """ Ingest arguments and init logging."""
     def init_logging(_user_arg):
         """ Pass user arg and configure logging module."""
@@ -732,7 +736,7 @@ def parse_args_logging():
         '-q', '-Q', '--quiet',
         dest='log_level',
         action='store_const',
-        # repurpose built-in logging level
+        # allow visible warnings in quiet mode
         const=logging.WARNING,
         help='suppress output')
     parser_mutex_grp.add_argument(
@@ -747,7 +751,7 @@ def parse_args_logging():
 
 def main():
     # configure and start logging
-    user_arg = parse_args_logging()
+    user_arg = parse_arg_logging()
     # instantiate CpuFreqTest as cpu_freq_test
     cpu_freq_test = CpuFreqTest()
     # provide access to reset() method