Acquire the import lock explicitly around the sys.setdlopenflags()

1 files changed, 15 insertions, 11 deletions

diff --git a/cffi/vengine_cpy.py b/cffi/vengine_cpy.py
index 1c4668c..9d5bf67 100644
--- a/cffi/vengine_cpy.py
+++ b/cffi/vengine_cpy.py
@@ -141,19 +141,23 @@ class VCPythonEngine(object):
     def load_library(self, flags=None):
         # XXX review all usages of 'self' here!
         # import it as a new extension module
-        if hasattr(sys, "getdlopenflags"):
-            previous_flags = sys.getdlopenflags()
+        imp.acquire_lock()
         try:
-            if hasattr(sys, "setdlopenflags") and flags is not None:
-                sys.setdlopenflags(flags)
-            module = imp.load_dynamic(self.verifier.get_module_name(),
-                                      self.verifier.modulefilename)
-        except ImportError as e:
-            error = "importing %r: %s" % (self.verifier.modulefilename, e)
-            raise ffiplatform.VerificationError(error)
+            if hasattr(sys, "getdlopenflags"):
+                previous_flags = sys.getdlopenflags()
+            try:
+                if hasattr(sys, "setdlopenflags") and flags is not None:
+                    sys.setdlopenflags(flags)
+                module = imp.load_dynamic(self.verifier.get_module_name(),
+                                          self.verifier.modulefilename)
+            except ImportError as e:
+                error = "importing %r: %s" % (self.verifier.modulefilename, e)
+                raise ffiplatform.VerificationError(error)
+            finally:
+                if hasattr(sys, "setdlopenflags"):
+                    sys.setdlopenflags(previous_flags)
         finally:
-            if hasattr(sys, "setdlopenflags"):
-                sys.setdlopenflags(previous_flags)
+            imp.release_lock()
         #
         # call loading_cpy_struct() to get the struct layout inferred by
         # the C compiler