Implementing a Monsoon power monitor trace agent, utilizing the UI infrastructure that the BattOr a…

systrace/systrace/tracing_controller.py

Index: systrace/systrace/tracing_controller.py
diff --git a/systrace/systrace/tracing_controller.py b/systrace/systrace/tracing_controller.py
index d0d2d7c3735988f4b4904a0a980ae87baeee86c7..368f9cd68acad60c7dc82661577c921114c63889 100644
--- a/systrace/systrace/tracing_controller.py
+++ b/systrace/systrace/tracing_controller.py
@@ -117,9 +117,31 @@ class TracingController(object):
     self._child_agents_with_config = agents_with_config
     self._controller_agent = TracingControllerAgent()
     self._controller_config = controller_config
+    self._connection_owner = None
     self._trace_in_progress = False
     self.all_results = None
 
+    # If we have a connection owner in the group, make an explicit reference to
+    # it.  We need to collect data from it before any other collectors as it may
+    # re-enable USB for the subsequent collectors to collect their data.
+    # In addition, move this agent to the end of the list so it is the last
+    # to start (it could disable USB).
+    connection_owner_with_config = None
+    sorted_agents_with_config = []
+
+    for agent_with_config in self._child_agents_with_config:
+      if agent_with_config.agent.IsConnectionOwner():
+        if connection_owner_with_config is not None:
+          raise Exception("Multiple connection owners found.")
+        connection_owner_with_config = agent_with_config
+      else:
+        sorted_agents_with_config.append(agent_with_config)
+
+    if connection_owner_with_config:
+      sorted_agents_with_config.append(connection_owner_with_config)
+      self._connection_owner = connection_owner_with_config.agent
+    self._child_agents_with_config = sorted_agents_with_config
+
   @property
   def get_child_agents(self):
     return self._child_agents
@@ -163,6 +185,7 @@ class TracingController(object):
     if ns < na:
       print 'Warning: Only %d of %d tracing agents started.' % (ns, na)
     self._child_agents = succ_agents
+
     return True
 
   def StopTracing(self):
@@ -179,6 +202,14 @@ class TracingController(object):
     assert self._trace_in_progress, 'No trace in progress.'
     self._trace_in_progress = False
 
+    # Explicity stop the connection owner (if any) tracing first, as it may
+    # re-enable USB.
+    if self._connection_owner:
+      sync_id = GetUniqueSyncID()
+      if not self._connection_owner.StopCollectionWithClockSync(sync_id,

[Zhen Wang, 2017/09/28 01:58:48]

Do we still need this |StopCollectionWithClockSync| function. Can we just call
StopAgentTracing here for connection owner?

It seems to me that StartAgentTracing takes care of USB disable. Similarly,
StopAgentTracing should take care of USB enable. You can make a comment in
__init__.py.

+        ControllerAgentClockSync):
+        print 'Connection owner failed to stop collection.'
+
     # Issue the clock sync marker and stop the child tracing agents.
     self._IssueClockSyncMarker()
     succ_agents = []