FIX: Experimental fix for race condition during tests in mem.clear()

joblib/disk.py

@@ -10,13 +10,14 @@
 import sys
 import os
 import shutil
+import time
 
 def disk_used(path):
     """ Return the disk usage in a directory. 
     """
     size = 0
     for file in os.listdir(path) + ['.']:
-        stat =  os.stat(os.path.join(path, file))
+        stat = os.stat(os.path.join(path, file))
         if hasattr(stat, 'st_blocks'):
             size += stat.st_blocks * 512
         else:
@@ -25,23 +26,26 @@ def disk_used(path):
             size += (stat.st_size // 512 + 1) * 512;
     # We need to convert to int to avoid having longs on some systems (we
     # don't want longs to avoid problems we SQLite)
-    return int(size/1024.)
+    return int(size / 1024.)
 
 
 def memstr_to_kbytes(text):
     """ Convert a memory text to it's value in kilobytes.
     """
     kilo = 1024
-    units = dict(K=1, M=kilo, G=kilo**2)
+    units = dict(K=1, M=kilo, G=kilo ** 2)
     try:
-        size = int(units[text[-1]]*float(text[:-1]))
+        size = int(units[text[-1]] * float(text[:-1]))
     except (KeyError, ValueError):
         raise ValueError(
                 "Invalid literal for size give: %s (type %s) should be "
                 "alike '10G', '500M', '50K'." % (text, type(text))
                 )
     return size
 
+# if a rmtree operation fails in rm_subdirs, wait for this much time (in secs),
+# then retry once. if it still fails, raise the exception
+RM_SUBDIRS_RETRY_TIME = 0.1
 
 def rm_subdirs(path, onerror=None):
     """Remove all subdirectories in this path.
@@ -67,8 +71,21 @@ def rm_subdirs(path, onerror=None):
             onerror(os.listdir, path, sys.exc_info())
         else:
             raise
-        
+
     for name in names:
         fullname = os.path.join(path, name)
         if os.path.isdir(fullname):
-            shutil.rmtree(fullname, False, onerror)
+            if onerror is not None:
+                shutil.rmtree(fullname, False, onerror)
+            else:
+                # allow the rmtree to fail once, wait and re-try.
+                # if the error is raised again, fail
+                err_count = 0
+                while True:
+                    try:
+                        shutil.rmtree(fullname, False, None)
+                        break
+                    except os.error, err:
+                        if err_count > 0: raise
+                        err_count += 1
+                        time.sleep(RM_SUBDIRS_RETRY_TIME)