Add exec rank for ventilator

yggdrasil/task_lib/ventilator.py

@@ -7,9 +7,10 @@ from .numbered_group import NumberedGroup
 class Ventilator(Executor):
 
     def __init__(self, name, commands, group, end=False, timeout=-1,
-            fail_threshold=0, encoding=consts.encoding) :
+            fail_threshold=0, encoding=consts.encoding, exec_rank="") :
         Executor.__init__(self, group, end, name, timeout, encoding)
         self.commands = commands
+        self.exec_rank= exec_rank
         self.to_exec  = len(commands)
         self.busy_map = dict()
         self.nbfail   = 0
@@ -19,8 +20,11 @@ class Ventilator(Executor):
         def got_spawn_list(data) :
             decoded_data = json.loads(data)
             spawn_list   = decoded_data[consts.DATA]
-            for spawn in spawn_list :
-                self.busy_map[spawn] = []
+            if self.exec_rank == "" :
+                for spawn in spawn_list :
+                    self.busy_map[spawn] = []
+            else :
+                self.busy_map[self.exec_rank] = []
             while self.assign_a_task() :
                 pass
         self.framework.acquire_spawn_list(self.group.ID,self.group.root_r,