address comments

tensorflow/c/c_api_experimental.h

@@ -305,7 +305,9 @@ TF_ImportGraphDefOptionsSetValidateColocationConstraints(
     TF_ImportGraphDefOptions* opts, unsigned char enable);
 
 // Load the library specified by library_filename and register the pluggable
-// device and related kernels present in that library.
+// device and related kernels present in that library. This function should work
+// on all the platforms supported by TensorFlow, apart from embedded/mobile
+// platforms.
 //
 // Pass "library_filename" to a platform-specific mechanism for dynamically
 // loading a library. The rules for determining the exact location of the
@@ -314,7 +316,7 @@ TF_ImportGraphDefOptionsSetValidateColocationConstraints(
 // On success, place OK in status and return the newly created library handle.
 // The caller owns the library handle.
 //
-// On failure, place an error status in status and return NULL.
+// On failure, return nullptr and places an error status in status.
 TF_CAPI_EXPORT extern TF_Library* TF_LoadPluggableDeviceLibrary(
     const char* library_filename, TF_Status* status);
 

tensorflow/python/eager/context.py

@@ -1243,7 +1243,12 @@ class Context(object):
     self._thread_local_data.invoking_op_callbacks = value
 
   def _initialize_physical_devices(self, reinitialize=False):
-    """Get local devices visible to the system."""
+    """Get local devices visible to the system.
+    
+    Args:
+      reinitialize: This flag will reinitialize self._physical_devices so that
+        dynamic registered devices will also be visible to the python front-end.
+    """
     # We lazy initialize self._physical_devices since we do not want to do this
     # the constructor since the backend may not be initialized yet.
     with self._device_lock: