Support custom hooks in IterBasedRunner.

Author: mzr1996

mmcv/runner/iter_based_runner.py

@@ -225,28 +225,48 @@ def register_training_hooks(self,
                                 optimizer_config=None,
                                 checkpoint_config=None,
                                 log_config=None,
-                                momentum_config=None):
+                                momentum_config=None,
+                                custom_hooks_config=None):
         """Register default hooks for iter-based training.
 
+        Checkpoint hook, optimizer stepper hook and logger hooks will be set to
+        `by_epoch=False` by default.
+
         Default hooks include:
 
-        - LrUpdaterHook
-        - MomentumUpdaterHook
-        - OptimizerStepperHook
-        - CheckpointSaverHook
-        - IterTimerHook
-        - LoggerHook(s)
+        +----------------------+-------------------------+
+        | Hooks                | Priority                |
+        +======================+=========================+
+        | LrUpdaterHook        | VERY_HIGH (10)          |
+        +----------------------+-------------------------+
+        | MomentumUpdaterHook  | HIGH (30)               |
+        +----------------------+-------------------------+
+        | OptimizerStepperHook | ABOVE_NORMAL (40)       |
+        +----------------------+-------------------------+
+        | CheckpointSaverHook  | NORMAL (50)             |
+        +----------------------+-------------------------+
+        | IterTimerHook        | LOW (70)                |
+        +----------------------+-------------------------+
+        | LoggerHook(s)        | VERY_LOW (90)           |
+        +----------------------+-------------------------+
+        | CustomHook(s)        | defaults to NORMAL (50) |
+        +----------------------+-------------------------+
+
+        If custom hooks have same priority with default hooks, custom hooks
+        will be triggered after default hooks.
         """
         if checkpoint_config is not None:
             checkpoint_config.setdefault('by_epoch', False)
         if lr_config is not None:
             lr_config.setdefault('by_epoch', False)
-        self.register_lr_hook(lr_config)
-        self.register_momentum_hook(momentum_config)
-        self.register_optimizer_hook(optimizer_config)
-        self.register_checkpoint_hook(checkpoint_config)
-        self.register_hook(IterTimerHook())
         if log_config is not None:
             for info in log_config['hooks']:
                 info.setdefault('by_epoch', False)
-        self.register_logger_hooks(log_config)
+        super(IterBasedRunner, self).register_training_hooks(
+            lr_config=lr_config,
+            momentum_config=momentum_config,
+            optimizer_config=optimizer_config,
+            checkpoint_config=checkpoint_config,
+            log_config=log_config,
+            timer_config=IterTimerHook(),
+            custom_hooks_config=custom_hooks_config)