Don't take the lock if the cutil is well compiled.

theano/gof/cc.py

@@ -1155,7 +1155,7 @@ class OpWiseCLinker(link.LocalLinker):
         # compilation will be finished. This allow to don't
         # require the lock when all c code are already compiled!
         keep_lock=True
-        orig_n_lock = get_lock.n_lock
+        orig_n_lock = getattr(get_lock,"n_lock",0)
         try:
 
             env = self.env

theano/gof/cutils.py

@@ -10,9 +10,17 @@ if os.path.exists(os.path.join(config.compiledir,'cutils_ext.so')):
 # Ensure no-one else is currently modifying the content of the compilation
 # directory. This is important to prevent multiple processes from trying to
 # compile the cutils_ext module simultaneously.
-get_lock()
 try:
+    from cutils_ext.cutils_ext import *
+except ImportError:
+    import cmodule
+
+    get_lock()
     try:
+        try:
+            # We must retry to import it as some other processs could
+            # have been compiling it between the first failed import
+            # and when we receive the lock
             from cutils_ext.cutils_ext import *
         except ImportError:
             import cmodule
@@ -61,7 +69,6 @@ try:
             cmodule.gcc_module_compile_str('cutils_ext', code, location=loc)
             from cutils_ext.cutils_ext import *
 
-finally:
+    finally:
         # Release lock on compilation directory.
         release_lock()
-