Move results directory check to start of client

Between the benchmark and collector modules, it's not clear who might
have created the output directory first.  Leave a warning in the
benchmark modules for now, otherwise don't let it prevent the tests from
running.

1 files changed, 6 insertions, 5 deletions

diff --git a/client/benchmarks/runner.py b/client/benchmarks/runner.py
index 41a3d7e..4d56187 100644
--- a/client/benchmarks/runner.py
+++ b/client/benchmarks/runner.py
@@ -56,10 +56,6 @@ class BenchmarkRunner(object):
 
         issues = {}
 
-        if os.path.exists(self._output):
-            issues['global'] = ["output directory '%s' already exists" %
-                                (self._output,)]
-
         for config_name in self._configs:
             t = self._check_config(config_name)
             if t:
@@ -124,7 +120,12 @@ class BenchmarkRunner(object):
     def run(self):
         'run all the configured benchmarks'
 
-        os.mkdir(self._output)
+        # It's ok if the output directory already exists.  One of the other
+        # collector modules may have started before the benchmark.
+        try:
+            os.mkdir(self._output)
+        except OSError as e:
+            log("WARNING: output directory already exists: %s" % self._output)
 
         for config_name in self._configs:
             self._run_config(config_name)