deprecate _update_called (#2141)

Co-authored-by: Jirka Borovec <6035284+Borda@users.noreply.github.com>
Co-authored-by: Nicki Skafte Detlefsen <skaftenicki@gmail.com>

Author: 3 people

CHANGELOG.md

@@ -25,6 +25,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Changed minimum supported Pytorch version from 1.8 to 1.10 ([#2145](https://github.com/Lightning-AI/torchmetrics/pull/2145))
 
+### Deprecated
+
+- Deprecated `metric._update_called` ([#2141](https://github.com/Lightning-AI/torchmetrics/pull/2141))
+
 
 ### Removed
 

src/torchmetrics/detection/mean_ap.py

@@ -348,6 +348,7 @@ class MeanAveragePrecision(Metric):
         "plot_upper_bound",
         "plot_legend_name",
         "metric_state",
+        "_update_called",
         # below is added for specifically for this metric
         "coco",
         "cocoeval",

src/torchmetrics/metric.py

@@ -87,6 +87,7 @@ class Metric(Module, ABC):
         "plot_upper_bound",
         "plot_legend_name",
         "metric_state",
+        "_update_called",
     ]
     is_differentiable: Optional[bool] = None
     higher_is_better: Optional[bool] = None
@@ -168,8 +169,12 @@ def __init__(
 
     @property
     def _update_called(self) -> bool:
-        # TODO: this is needed for internal lightning, remove after v0.12 and update on lightning side
-        return self._update_count > 0
+        rank_zero_warn(
+            "This property will be removed in 2.0.0. Use `Metric.updated_called` instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return self.update_called
 
     @property
     def update_called(self) -> bool: