avocado.test: Add Test __getstate__ for serialization

In order to make the Test class serializable, implement
__getstate__ in a way that only exports the pickleable
attributes. This will be necessary for the following
patches that will insulate individual test executions
in forked processes.
Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

avocado/test.py

@@ -51,9 +51,11 @@ def log_exc_info(exc_info):
 
     :param exc_info: Exception info produced by sys.exc_info()
     """
+    log.error('')
     for line in tb_info(exc_info):
         for l in line.splitlines():
             log.error(l)
+    log.error('')
 
 
 def prepare_exc_info(exc_info):
@@ -102,6 +104,7 @@ class Test(unittest.TestCase):
         if params is None:
             params = {}
         self.params = Params(params)
+        self._raw_params = params
 
         shortname = self.params.get('shortname')
         s_tag = None
@@ -152,6 +155,13 @@ class Test(unittest.TestCase):
         self.log.debug('Test instance params override defaults whenever available')
         self.log.debug('')
 
+        # If there's a timeout set, log a timeout reminder
+        if hasattr(self.params, 'timeout'):
+            self.log.info('Test timeout set. Will wait %.2f s for '
+                          'PID %s to end',
+                          float(self.params.timeout), os.getpid())
+            self.log.info('')
+
         self.debugdir = None
         self.resultsdir = None
         self.status = None
@@ -169,6 +179,26 @@ class Test(unittest.TestCase):
     def __repr__(self):
         return "Test(%r)" % self.tagged_name
 
+    def __getstate__(self):
+        """
+        Pickle only selected attributes of the class for serialization.
+
+        The fact we serialize the class means you'll have to modify this
+        class if you intend to make significant changes to its structure.
+        """
+        orig = dict(self.__dict__)
+        d = {}
+        preserve_attr = ['basedir', 'debugdir', 'depsdir', 'fail_class',
+                         'fail_reason', 'logdir', 'logfile', 'name',
+                         'resultsdir', 'srcdir', 'status', 'sysinfodir',
+                         'tag', 'tagged_name', 'text_output', 'time_elapsed',
+                         'traceback', 'workdir']
+        for key in sorted(orig):
+            if key in preserve_attr:
+                d[key] = orig[key]
+        d['params'] = orig['_raw_params']
+        return d
+
     def _set_default(self, key, default):
         try:
             self.params[key]