Implementing a grouping feature to organize flow operations

doc/api.rst

@@ -37,6 +37,7 @@ The FlowProject
     FlowProject.label
     FlowProject.labels
     FlowProject.main
+    FlowProject.make_group
     FlowProject.next_operation
     FlowProject.next_operations
     FlowProject.operation
@@ -139,3 +140,16 @@ flow.get_environment()
 ----------------------
 
 .. autofunction:: get_environment
+
+The FlowGroup
+----------
+
+.. autoclass:: flow.project.FlowGroup
+
+.. automethod:: flow.project.FlowGroup.add_operation
+
+.. automethod:: flow.project.FlowGroup.complete
+
+.. automethod:: flow.project.FlowGroup.eligible
+
+.. automethod:: flow.project.FlowGroup.isdisjoint

flow/environments/xsede.py

@@ -51,6 +51,7 @@ class Stampede2Environment(DefaultSlurmEnvironment):
     template = 'stampede2.sh'
     cores_per_node = 48
     mpi_cmd = 'ibrun'
+    offset_counter = 0
 
     @classmethod
     def add_args(cls, parser):
@@ -84,13 +85,16 @@ def _get_mpi_prefix(cls, operation, parallel):
         """
         if operation.directives.get('nranks'):
             if parallel:
-                return '{} -n {} -o {} task_affinity '.format(
-                       cls.mpi_cmd, operation.directives['nranks'],
-                       operation.directives['np_offset'])
+                prefix = '{} -n {} -o {} task_affinity '.format(
+                          cls.mpi_cmd, operation.directives['nranks'],
+                          cls.offset_counter)
+                cls.offset_counter += operation.directives['nranks']
             else:
-                return '{} -n {} '.format(cls.mpi_cmd, operation.directives['nranks'])
+                prefix = '{} -n {} '.format(cls.mpi_cmd,
+                                            operation.directives['nranks'])
         else:
-            return ''
+            prefix = ''
+        return prefix
 
 
 class BridgesEnvironment(DefaultSlurmEnvironment):