[IPU] Add hooks for IPU lifecycle 4/5 (#7864)

Author: Sean Naren

CHANGELOG.md

@@ -62,6 +62,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Added reset dataloader hooks to Training Plugins and Accelerators ([#7861](https://github.com/PyTorchLightning/pytorch-lightning/pull/7861))
 
 
+- Added trainer stage hooks for Training Plugins and Accelerators ([#7864](https://github.com/PyTorchLightning/pytorch-lightning/pull/7864))
+
+
 ### Changed
 
 - Changed calling of `untoggle_optimizer(opt_idx)` out of the closure function ([#7563](https://github.com/PyTorchLightning/pytorch-lightning/pull/7563)

pytorch_lightning/accelerators/accelerator.py

@@ -179,10 +179,6 @@ def batch_to_device(
 
         return move_data_to_device(batch, device)
 
-    def on_train_start(self) -> None:
-        """Hook to do something upon the training start"""
-        pass
-
     def training_step(
         self,
         step_kwargs: Dict[str, Union[Any, int]],
@@ -348,14 +344,6 @@ def clip_gradients(
             model=self.model,
         )
 
-    def on_train_epoch_end(self) -> None:
-        """Hook to do something on the end of an training epoch."""
-        pass
-
-    def on_train_end(self) -> None:
-        """Hook to do something at the end of the training"""
-        pass
-
     def setup_optimizers(self, trainer: 'pl.Trainer') -> None:
         """
         Creates optimizers and schedulers
@@ -563,3 +551,45 @@ def setup_optimizers_in_pre_dispatch(self) -> bool:
 
     def update_global_step(self, total_batch_idx: int, current_global_step: int) -> int:
         return self.training_type_plugin.update_global_step(total_batch_idx, current_global_step)
+
+    def on_train_epoch_end(self) -> None:
+        """Hook to do something on the end of an training epoch."""
+        pass
+
+    def on_train_start(self) -> None:
+        """Called when train begins."""
+        return self.training_type_plugin.on_train_start()
+
+    def on_validation_start(self) -> None:
+        """Called when validation begins."""
+        return self.training_type_plugin.on_validation_start()
+
+    def on_test_start(self) -> None:
+        """Called when test begins."""
+        return self.training_type_plugin.on_test_start()
+
+    def on_predict_start(self) -> None:
+        """Called when predict begins."""
+        return self.training_type_plugin.on_predict_start()
+
+    def on_validation_end(self) -> None:
+        """Called when validation ends."""
+        return self.training_type_plugin.on_validation_end()
+
+    def on_test_end(self) -> None:
+        """Called when test end."""
+        return self.training_type_plugin.on_test_end()
+
+    def on_predict_end(self) -> None:
+        """Called when predict ends."""
+        return self.training_type_plugin.on_predict_end()
+
+    def on_train_end(self) -> None:
+        """Called when train ends."""
+        return self.training_type_plugin.on_train_end()
+
+    def on_train_batch_start(self, batch: Any, batch_idx: int, dataloader_idx: int) -> None:
+        """
+        Called in the training loop before anything happens for that batch.
+        """
+        return self.training_type_plugin.on_train_batch_start(batch, batch_idx, dataloader_idx)

pytorch_lightning/plugins/training_type/training_type_plugin.py

@@ -330,3 +330,41 @@ def register_plugins(cls, plugin_registry):
     def should_rank_save_checkpoint(self) -> bool:
         """Returns whether the checkpoint should be saved (rank based)"""
         return self.is_global_zero
+
+    def on_train_start(self) -> None:
+        """Called when train begins."""
+        pass
+
+    def on_validation_start(self) -> None:
+        """Called when validation begins."""
+        pass
+
+    def on_test_start(self) -> None:
+        """Called when test begins."""
+        pass
+
+    def on_predict_start(self) -> None:
+        """Called when predict begins."""
+        pass
+
+    def on_train_end(self) -> None:
+        """Called when train ends."""
+        pass
+
+    def on_validation_end(self) -> None:
+        """Called when validation ends."""
+        pass
+
+    def on_test_end(self) -> None:
+        """Called when test end."""
+        pass
+
+    def on_predict_end(self):
+        """Called when predict ends."""
+        pass
+
+    def on_train_batch_start(self, batch: Any, batch_idx: int, dataloader_idx: int) -> None:
+        """
+        Called in the training loop before anything happens for that batch.
+        """
+        pass