fix bug in PeriodicRunHooks

tensorpack/callbacks/trigger.py

@@ -63,10 +63,13 @@ class PeriodicRunHooks(ProxyCallback):
 
     def _before_run(self, ctx):
         if self.global_step % self._every_k_steps == 0:
+            self._enabled = True
             return self.cb._before_run(ctx)
+        else:
+            self._enabled = False
 
     def _after_run(self, ctx, rv):
-        if self.global_step % self._every_k_steps == 0:
+        if self._enabled:
             self.cb._after_run(ctx, rv)
 
     def __str__(self):
@@ -80,8 +83,8 @@ class EnableCallbackIf(ProxyCallback):
     The other methods will be called the same.
 
     Note:
-        If you need to use ``{before,after}_run``, make sure
-        that ``pred`` will eval to the same results in both methods every step.
+        If you use ``{before,after}_run``,
+        ``pred`` will be evaluated only in ``before_run``.
     """
     def __init__(self, callback, pred):
         """
@@ -94,10 +97,13 @@ class EnableCallbackIf(ProxyCallback):
 
     def _before_run(self, ctx):
         if self._pred(self):
+            self._enabled = True
             return super(EnableCallbackIf, self)._before_run(ctx)
+        else:
+            self._enabled = False
 
     def _after_run(self, ctx, rv):
-        if self._pred(self):
+        if self._enabled:
             super(EnableCallbackIf, self)._after_run(ctx, rv)
 
     def _before_epoch(self):