[Bug fix] Do not sample right after flushing profile

There was a bug introduced from Issue #15 where we attempt to sample
right after flushing profiles even is_profiling_in_progress has been
reset to False already

Author: Colman Yau

codeguru_profiler_agent/model/profile.py

@@ -43,9 +43,9 @@ def end(self):
     @end.setter
     def end(self, value):
         self._validate_positive_number(value)
-        if value < self.start:
+        if value <= self.start:
             raise ValueError(
-                "Profile end value must be greater than or equal to {}, got {}".format(self.start, value))
+                "Profile end value must be greater than {}, got {}".format(self.start, value))
         self._end = value
         # this is the total cpu time spent in this application since start, not just the overhead
         self.cpu_time_seconds = time.process_time() - self._start_process_time

codeguru_profiler_agent/profiler_runner.py

@@ -88,6 +88,7 @@ def _run_profiler(self):
         if self.is_profiling_in_progress:
             if self.collector.flush():
                 self.is_profiling_in_progress = False
+                return True
             sample = self.sampler.sample()
             self.collector.add(sample)
         return True

test/acceptance/test_live_profiling.py

@@ -70,7 +70,9 @@ def test_live_profiling(self):
                 finally:
                     profiler.stop()
 
-                assert wrapped_add.call_count >= 3
+                # We should only see 2 sample in 3 seconds as the sequence should happen in the order of
+                # no flush -> sample -> no flush -> sample -> flush (without sample)
+                assert wrapped_add.call_count >= 2
                 assert wrapped_post_agent_profile.call_count >= 1
                 assert wrapped_configure_agent.call_count >= 1
                 assert AgentConfiguration.get().sampling_interval == timedelta(seconds=1)

test/unit/test_profiler_runner.py

@@ -73,6 +73,13 @@ def test_when_it_is_time_to_report_it_refreshes_configuration_again(self):
         self.profiler_runner._profiling_command()
         self.mock_collector.refresh_configuration.assert_called_once()
 
+    def test_when_it_does_not_sample_when_it_reports(self):
+        self.is_time_to_report = True
+
+        assert(self.profiler_runner._profiling_command())
+        self.mock_collector.flush.assert_called_once()
+        self.mock_collector.add.assert_not_called()
+
     def test_when_disabler_say_to_stop(self):
         self.mock_disabler.should_stop_profiling.return_value = True
         self.profiler_runner._profiling_command()