Remove reference cycle in VecAccessMixin

firedrake/function.py

@@ -84,7 +84,7 @@ def __init__(self, function_space, val=None, name=None, dtype=ScalarType):
         else:
             self.dat = function_space.make_dat(val, dtype, self.name())
 
-    @utils.cached_property
+    @property
     def topological(self):
         r"""The underlying coordinateless function."""
         return self

firedrake/preconditioners/patch.py

@@ -127,6 +127,9 @@ def _wrapper_cache_key_(self):
     def __call__(self, access, map_=None):
         return LocalDatLegacyArg(self, map_, access)
 
+    def increment_dat_version(self):
+        pass
+
 
 register_petsc_function("MatSetValues")
 

pyop2/types/dat.py

@@ -725,6 +725,9 @@ def __init__(self, dat, index):
                                       dtype=dat.dtype,
                                       name="view[%s](%s)" % (index, dat.name))
 
+    def increment_dat_version(self):
+        self._parent.increment_dat_version()
+
     @utils.cached_property
     def _kernel_args_(self):
         return self._parent._kernel_args_
@@ -841,6 +844,9 @@ def vec_context(self, access):
         if access is not Access.READ:
             self.halo_valid = False
 
+    def increment_dat_version(self):
+        VecAccessMixin.increment_dat_version(self)
+
 
 class MixedDat(AbstractDat, VecAccessMixin):
     r"""A container for a bag of :class:`Dat`\s.

pyop2/types/data_carrier.py

@@ -44,6 +44,7 @@ def cdim(self):
         the product of the dim tuple."""
         return self._cdim
 
+    @abc.abstractmethod
     def increment_dat_version(self):
         pass
 
@@ -80,24 +81,21 @@ def _is_allocated(self):
 class VecAccessMixin(abc.ABC):
 
     def __init__(self, petsc_counter=None):
-        if petsc_counter:
-            # Use lambda since `_vec` allocates the data buffer
-            # -> Dat/Global should not allocate storage until accessed
-            self._dat_version = lambda: self._vec.stateGet()
-            self.increment_dat_version = lambda: self._vec.stateIncrease()
-        else:
-            # No associated PETSc Vec if incompatible type:
-            # -> Equip Dat/Global with their own counter.
-            self._version = 0
-            self._dat_version = lambda: self._version
-
-            def _inc():
-                self._version += 1
-            self.increment_dat_version = _inc
+        self._petsc_counter = petsc_counter
+        self._version = 0
 
     @property
     def dat_version(self):
-        return self._dat_version()
+        if self._petsc_counter:
+            return self._vec.stateGet()
+
+        return self._version
+
+    def increment_dat_version(self):
+        if self._petsc_counter:
+            self._vec.stateIncrease()
+        else:
+            self._version += 1
 
     @abc.abstractmethod
     def vec_context(self, access):

pyop2/types/glob.py

@@ -399,6 +399,9 @@ def vec_context(self, access):
             data = self._data
             self.comm.Bcast(data, 0)
 
+    def increment_dat_version(self):
+        VecAccessMixin.increment_dat_version(self)
+
 
 # has no comm, can only be READ
 class Constant(SetFreeDataCarrier):
@@ -464,3 +467,6 @@ def duplicate(self):
             dtype=self.dtype,
             name=self.name
         )
+
+    def increment_dat_version(self):
+        pass

pyop2/types/mat.py

@@ -550,6 +550,9 @@ def __repr__(self):
         return "Mat(%r, %r, %r)" \
                % (self._sparsity, self._datatype, self._name)
 
+    def increment_dat_version(self):
+        pass
+
 
 class Mat(AbstractMat):
     """OP2 matrix data. A Mat is defined on a sparsity pattern and holds a value