Delete ScopedTFStatus to avoid leaking it for long running trainers(1+day).

PiperOrigin-RevId: 168259652

tensorflow/python/framework/errors_impl.py

@@ -459,8 +459,13 @@ def _make_specific_exception(node_def, op, message, error_code):
 def raise_exception_on_not_ok_status():
   status = c_api_util.ScopedTFStatus()
   yield status.status
-  if c_api.TF_GetCode(status) != 0:
-    raise _make_specific_exception(
-        None, None,
-        compat.as_text(c_api.TF_Message(status)),
-        c_api.TF_GetCode(status))
+  try:
+    if c_api.TF_GetCode(status.status) != 0:
+      raise _make_specific_exception(
+          None, None,
+          compat.as_text(c_api.TF_Message(status.status)),
+          c_api.TF_GetCode(status.status))
+  # Delete the underlying status object from memory otherwise it stays alive
+  # as there is a reference to status from this from the traceback due to raise.
+  finally:
+    del status

tensorflow/python/framework/errors_test.py

@@ -18,16 +18,23 @@ from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
 
+import gc
 import warnings
 
 from tensorflow.core.lib.core import error_codes_pb2
+from tensorflow.python import pywrap_tensorflow
+from tensorflow.python.framework import c_api_util
 from tensorflow.python.framework import errors
 from tensorflow.python.framework import errors_impl
 from tensorflow.python.platform import test
+from tensorflow.python.util import compat
 
 
 class ErrorsTest(test.TestCase):
 
+  def _CountReferences(self, typeof):
+    return len([o for o in gc.get_objects() if isinstance(o, typeof)])
+
   def testUniqueClassForEachErrorCode(self):
     for error_code, exc_type in [
         (errors.CANCELLED, errors_impl.CancelledError),
@@ -80,6 +87,16 @@ class ErrorsTest(test.TestCase):
     self.assertTrue("Unknown error code: 37" in str(w[0].message))
     self.assertTrue(isinstance(exc, errors_impl.OpError))
 
+  def testStatusDoesNotLeak(self):
+    try:
+      with errors.raise_exception_on_not_ok_status() as status:
+        pywrap_tensorflow.DeleteFile(
+            compat.as_bytes("/DOES_NOT_EXIST/"), status)
+    except:
+      pass
+    gc.collect()
+    self.assertEqual(0, self._CountReferences(c_api_util.ScopedTFStatus))
+
 
 if __name__ == "__main__":
   test.main()