sched: raise a ValueError in get_pids_for_process() if the trace doesn't contain sched_switch events

2 files changed, 42 insertions, 0 deletions

diff --git a/bart/sched/functions.py b/bart/sched/functions.py
index 546e8fb..8a3d7a0 100644
--- a/bart/sched/functions.py
+++ b/bart/sched/functions.py
@@ -436,6 +436,9 @@ def get_pids_for_process(ftrace, execname, cls=None):
             df = ftrace.sched_switch.data_frame
         except AttributeError:
             raise ValueError("SchedSwitch event not found in ftrace")
+
+        if len(df) == 0:
+            raise ValueError("SchedSwitch event not found in ftrace")
     else:
         event = getattr(ftrace, cls.name)
         df = event.data_frame
diff --git a/tests/test_sched_functions.py b/tests/test_sched_functions.py
new file mode 100644
index 0000000..164df3c
--- /dev/null
+++ b/tests/test_sched_functions.py
@@ -0,0 +1,39 @@
+#    Copyright 2016-2016 ARM Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+import trappy
+
+import utils_tests
+
+class TestSchedFunctions(utils_tests.SetupDirectory):
+    def __init__(self, *args, **kwargs):
+        super(TestSchedFunctions, self).__init__([], *args, **kwargs)
+
+    def test_get_pids_for_processes_no_sched_switch(self):
+        """get_pids_for_processes() raises an exception if the trace doesn't have a sched_switch event"""
+        from bart.sched.functions import get_pids_for_process
+
+        trace_file = "trace.txt"
+        raw_trace_file = "trace.raw.txt"
+
+        with open(trace_file, "w") as fout:
+            fout.write("")
+
+        with open(raw_trace_file, "w") as fout:
+            fout.write("")
+
+        trace = trappy.FTrace(trace_file)
+        with self.assertRaises(ValueError):
+            get_pids_for_process(trace, "foo")