Fix subtle race condition in ResourceVariable.is_initialized

PiperOrigin-RevId: 186544846

1 files changed, 8 insertions, 0 deletions

diff --git a/tensorflow/core/kernels/variable_ops.h b/tensorflow/core/kernels/variable_ops.h
index 83134bad37..8b406e5311 100644
--- a/tensorflow/core/kernels/variable_ops.h
+++ b/tensorflow/core/kernels/variable_ops.h
@@ -45,6 +45,14 @@ class Var : public ResourceBase {
                            tensor_.shape().DebugString());
   }
 
+  // Only used in the resource variable path. In resource variables,
+  // tensor.IsInitialized() can be true (i.e. have memory allocated to it) while
+  // there is not a good value there due to a race condition, and it's possible
+  // to stumble upon this during variable.initialized_value(). So it's best to
+  // just store directly whether the variable is initialized.
+  bool is_initialized = false;  // GUARDED_BY(mu_) but annotalysis doesn't like
+                                // it.
+
  private:
   mutex mu_;
   Tensor tensor_;