2 # NEPI, a framework to manage network experiments
3 # Copyright (C) 2013 INRIA
5 # This program is free software: you can redistribute it and/or modify
6 # it under the terms of the GNU General Public License version 2 as
7 # published by the Free Software Foundation;
9 # This program is distributed in the hope that it will be useful,
10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 # GNU General Public License for more details.
14 # You should have received a copy of the GNU General Public License
15 # along with this program. If not, see <http://www.gnu.org/licenses/>.
17 # Author: Alina Quereilhac <alina.quereilhac@inria.fr>
25 """ Execution state of the Task
32 """ A Task represents an operation to be executed by the
33 ExperimentController scheduler
36 def __init__(self, timestamp, callback):
38 :param timestamp: Future execution date of the operation
41 :param callback: A function to invoke in order to execute the operation
42 :type callback: function
46 self.timestamp = timestamp
47 self.callback = callback
49 self.status = TaskStatus.NEW
51 class HeapScheduler(object):
52 """ Create a Heap Scheduler
56 This class is thread safe.
57 All calls to C Extensions are made atomic by the GIL in the CPython implementation.
58 heapq.heappush, heapq.heappop, and list access are therefore thread-safe.
63 super(HeapScheduler, self).__init__()
66 self._idgen = itertools.count(1)
70 """ Returns the list of pending task ids """
73 def schedule(self, task):
74 """ Add a task to the queue ordered by task.timestamp and arrival order
76 :param task: task to schedule
80 task.id = next(self._idgen)
82 entry = (task.timestamp, task.id, task)
83 self._valid.add(task.id)
84 heapq.heappush(self._queue, entry)
87 def remove(self, tid):
88 """ Remove a task form the queue
90 :param tid: Id of the task to be removed
95 self._valid.remove(tid)
104 """ Get the next task in the queue by timestamp and arrival order
108 timestamp, tid, task = heapq.heappop(self._queue)
109 if tid in self._valid: