Merge pull request #918 from rainwoodman/mock-model-cycles

Remove reference cycles between MockFactory and ModelFactory.

halotools/empirical_models/composite_models/tests/test_preloaded_models.py

@@ -1,5 +1,6 @@
 """
 """
+import sys
 import pytest
 import numpy as np
 
@@ -13,6 +14,25 @@
 __all__ = ('test_hearin15', )
 
 
+
+@pytest.mark.skipif(sys.platform == 'win32',
+                    reason="does not run on windows")
+def test_memory_leak():
+    model = PrebuiltHodModelFactory('hearin15')
+    halocat = FakeSim()
+    import resource
+
+    model.populate_mock(halocat)
+    maxrss = []
+    for i in range(9):
+        model.mock.populate()
+        maxrss.append(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss)
+
+    import numpy
+    # memory usage shall not increase significantly per run.
+    assert (numpy.diff(maxrss) < 1024).all()
+
+
 def test_hearin15():
     """
     """

halotools/empirical_models/factories/mock_factory_template.py

@@ -14,6 +14,7 @@
 from .mock_helpers import three_dim_pos_bundle, infer_mask_from_kwargs
 
 from .. import model_helpers, model_defaults
+import weakref
 
 try:
     from ... import mock_observables
@@ -76,6 +77,7 @@ def __init__(self, **kwargs):
         except:
             pass
 
+
         # Create a list of halo properties that will be inherited by the mock galaxies
         self.additional_haloprops = copy(model_defaults.default_haloprop_list_inherited_by_mock)
 
@@ -86,6 +88,15 @@ def __init__(self, **kwargs):
 
         self.galaxy_table = Table()
 
+    @property
+    def model(self):
+        """ model, a weak reference to the model because mock is always a member of model """
+        return self._model()
+
+    @model.setter
+    def model(self, value):
+        self._model = weakref.ref(value)
+
     @abstractmethod
     def populate(self, **kwargs):
         """

halotools/empirical_models/factories/model_factory_template.py

@@ -276,12 +276,17 @@ def update_param_dict_decorator(self, component_model, func_name):
         :ref:`param_dict_mechanism`
         """
 
+        # do not pass self into the scope;
+        # assuming param_dict is not replaced during life cycle of self.
+        # passing `self` causes a cycle reference when
+        # the function is assigned as attributes of self.
+        __param_dict__ = self.param_dict
         def decorated_func(*args, **kwargs):
 
             # Update the param_dict as necessary
-            for key in list(self.param_dict.keys()):
+            for key in list(__param_dict__.keys()):
                 if key in component_model.param_dict:
-                    component_model.param_dict[key] = self.param_dict[key]
+                    component_model.param_dict[key] = __param_dict__[key]
 
             func = getattr(component_model, func_name)
             return func(*args, **kwargs)