diff options
Diffstat (limited to 'coverage/collector.py')
| -rw-r--r-- | coverage/collector.py | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/coverage/collector.py b/coverage/collector.py index 55211f2a..d20e42cc 100644 --- a/coverage/collector.py +++ b/coverage/collector.py @@ -96,8 +96,13 @@ class PyTracer(object): return self._trace def start(self): - """Start this Tracer.""" + """Start this Tracer. + + Return a Python function suitable for use with sys.settrace(). + + """ sys.settrace(self._trace) + return self._trace def stop(self): """Stop this Tracer.""" @@ -186,8 +191,9 @@ class Collector(object): tracer.arcs = self.branch tracer.should_trace = self.should_trace tracer.should_trace_cache = self.should_trace_cache - tracer.start() + fn = tracer.start() self.tracers.append(tracer) + return fn # The trace function has to be set individually on each thread before # execution begins. Ironically, the only support the threading module has @@ -200,9 +206,13 @@ class Collector(object): # Remove ourselves as the trace function sys.settrace(None) # Install the real tracer. - self._start_tracer() - # Return None to reiterate that we shouldn't be used for tracing. - return None + fn = self._start_tracer() + # Invoke the real trace function with the current event, to be sure + # not to lose an event. + if fn: + fn = fn(frame_unused, event_unused, arg_unused) + # Return the new trace function to continue tracing in this scope. + return fn def start(self): """Start collecting trace information.""" |