Issue #114: call close on FileExecutor and Harvester

At the end of the job, after processing all the files, call close on
FileExecutor and Harvester.

This allows to do clean up stuff like shutting down any runner still
alive in the FileExecutor.

byexample/executor.py

@@ -131,6 +131,12 @@ def reset_runners(self, runners, should_raise=True, force_shutdown=True):
 
         assert not left
 
+    @log_context('byexample.close')
+    def close(self):
+        self.reset_runners(
+            self.still_alive_runners, should_raise=True, force_shutdown=True
+        )
+
     def __repr__(self):
         return 'File Executor'
 

byexample/finder.py

@@ -107,6 +107,10 @@ def __init__(
 
         self.options = options
 
+    @log_context('byexample.close')
+    def close(self):
+        pass
+
     def __repr__(self):
         return 'Example Harvester'
 

byexample/jobs.py

@@ -27,6 +27,9 @@ def worker(func, input, output, cfg):
     for item in iter(input.get, None):
         output.put(func(item, harvester, executor, cfg['dry']))
 
+    harvester.close()
+    executor.close()
+
 
 class Jobs(object):
     def __init__(self, njobs):