setting autosave=False in PV overrides context manager

docs/reference/api.rst

@@ -210,7 +210,9 @@ and stderr streams, is sent directly to the terminal.
             the context manager added to autosave tracking. The options for ``autosave``
             are identical to the ones described in the builder keyword argument
             :ref:`autosave`. If a PV already has :ref:`autosave` set, the two lists of fields
-            get combined into a single set.
+            get combined into a single set. If the PV's :ref:`autosave` keyword is set
+            explicitly to ``False``, the fields specified in the context manager's argument
+            are not tracked.
 
 
 
@@ -338,8 +340,8 @@ and stderr streams, is sent directly to the terminal.
     ~~~~~~~~~~~~~~~
 
     Available on all record types. 
-    Resoles to a list of string field names, when not empty it marks the record
-    fields for automatic periodic backing up to a file. Set to `False` by
+    Resolves to a list of string field names. When not empty it marks the record
+    fields for automatic periodic backing up to a file. Set to `None` by
     default. When the IOC is restarted and a backup file exists, the saved values are
     loaded from this file when :func:`~softioc.builder.LoadDatabase` is called.
     The saved values takes priority over any initial field value passed to the PV
@@ -349,13 +351,16 @@ and stderr streams, is sent directly to the terminal.
     The options for the argument are:
 
         * ``True``, which is equivalent to ``["VAL"]``
-        * ``False``, which is equivalent to ``[]`` and disables autosave tracking for the PV
+        * ``False``, which is equivalent to ``[]`` and disables all autosave tracking for the PV, even inside an :class:`~softioc.autosave.Autosave` context manager
+        * ``None``, similar to ``False`` but does not overload any fields specified in an :class:`~softioc.autosave.Autosave` context manager
         * A list of field names such as ``["VAL", "LOPR", "HOPR"]``, note that ``"VAL"`` must be explicitly provided
-        * A single field name such as ``"EGU"`` which is equivalent to passing ``["EGU"]``.
+        * A single field name such as ``"EGU"`` which is equivalent to passing ``["EGU"]``
 
     .. seealso::
         :func:`~softioc.autosave.configure` for discussion on how to configure saving.
 
+        :class:`~softioc.autosave.Autosave` for how to track PVs with autosave inside a context manager.
+
 
 For all of these functions any EPICS database field can be assigned a value by
 passing it as a keyword argument for the corresponding field name (in upper

softioc/autosave.py

@@ -81,7 +81,7 @@ def _shutdown_autosave_thread(worker):
 
 
 def _parse_autosave_fields(fields):
-    if fields is False:
+    if not fields:
         return []
     elif fields is True:
         return ["VAL"]
@@ -107,9 +107,12 @@ def add_pv_to_autosave(pv, name, fields):
             created inside an Autosave context manager, the fields passed to the
             context manager are also tracked by autosave.
     """
-    context = _AutosaveContext()
+    if fields is False:
+        # if autosave=False explicitly set, override context manager
+        return
     fields = set(_parse_autosave_fields(fields))
-    # instantiate to get thread local class variables via instance
+    # instantiate context to get thread local class variables via instance
+    context = _AutosaveContext()
     if context._in_cm:  # _fields should always be a list if in context manager
         fields.update(context._fields)
     for field in fields:

softioc/device.py

@@ -55,7 +55,7 @@ class ProcessDeviceSupportCore(DeviceSupportCore, RecordLookup):
 
     # all record types can support autosave
     def __init__(self, name, **kargs):
-        autosave_fields = kargs.pop("autosave", False)
+        autosave_fields = kargs.pop("autosave", None)
         autosave.add_pv_to_autosave(self, name, autosave_fields)
         self.__super.__init__(name, **kargs)
 

tests/test_autosave.py

@@ -471,7 +471,7 @@ def test_autosave_arguments(tmp_path):
         builder.aOut("AUTO-TRUE", autosave=False)
         builder.aOut("FIELDS", autosave=["LOPR", "HOPR"])
     assert set(autosave.Autosave._pvs) == {
-        "AUTO-TRUE", "FIELDS", "FIELDS.LOPR", "FIELDS.HOPR"}
+        "FIELDS", "FIELDS.LOPR", "FIELDS.HOPR"}
     autosave.Autosave._pvs = {}
     builder.ClearRecords()
     with autosave.Autosave(["EGU"]):
@@ -482,7 +482,7 @@ def test_autosave_arguments(tmp_path):
     autosave.Autosave._pvs = {}
     builder.ClearRecords()
     with autosave.Autosave(False):
-        builder.aOut("AUTO-FALSE")
+        builder.aOut("AUTO-DEFAULT")
         builder.aOut("AUTO-TRUE", autosave=True)
     assert set(autosave.Autosave._pvs) == {"AUTO-TRUE"}
     autosave.Autosave._pvs = {}