WIP: Graph datahandling

This is the draft for a data handling that (optionally) forwards all calls to SerialDatahandling. All calls and data transfers get recorded for the creation of an execution graph.

Needs to be changed after the breaking changes in datahandling.

Needs a tiny change in lbmpy:

Instead of using TimeLoop(...) for time loop creation a custom function is used.

pystencils/kernelcreation.py

@@ -130,6 +130,7 @@ def create_kernel(assignments,
     if use_auto_for_assignments:
         for a in ast.atoms(SympyAssignment):
             a.use_auto = True
+    ast.assignments = assignments
 
     return ast
 
@@ -184,6 +185,7 @@ def create_indexed_kernel(assignments,
         assignments = [assignments]
     elif isinstance(assignments, AssignmentCollection):
         assignments = assignments.all_assignments
+
     if target == 'cpu':
         from pystencils.cpu import create_indexed_kernel
         from pystencils.cpu import add_openmp
@@ -191,7 +193,6 @@ def create_indexed_kernel(assignments,
                                     coordinate_names=coordinate_names)
         if cpu_openmp:
             add_openmp(ast, num_threads=cpu_openmp)
-        return ast
     elif target == 'llvm':
         raise NotImplementedError("Indexed kernels are not yet supported in LLVM backend")
     elif target == 'gpu' or target == 'opencl':
@@ -209,10 +210,12 @@ def create_indexed_kernel(assignments,
             ast.compile = functools.partial(make_python_function, ast, opencl_queue, opencl_ctx)
             ast._target = 'opencl'
             ast._backend = 'opencl'
-        return ast
     else:
         raise ValueError("Unknown target %s. Has to be either 'cpu' or 'gpu'" % (target,))
 
+    ast.assignments = assignments
+    return ast
+
 
 def create_staggered_kernel(assignments, target='cpu', gpu_exclusive_conditions=False, **kwargs):
     """Kernel that updates a staggered field.