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>
23 """ Execution state of the Task
30 """ A Task represents an operation to be executed by the
31 ExperimentController scheduler
34 def __init__(self, timestamp, callback):
36 :param timestamp: Future execution date of the operation
39 :param callback: A function to invoke in order to execute the operation
40 :type callback: function
44 self.timestamp = timestamp
45 self.callback = callback
47 self.status = TaskStatus.NEW
49 class HeapScheduler(object):
50 """ Create a Heap Scheduler
54 This class is thread safe.
55 All calls to C Extensions are made atomic by the GIL in the CPython implementation.
56 heapq.heappush, heapq.heappop, and list access are therefore thread-safe.
61 super(HeapScheduler, self).__init__()
64 self._idgen = itertools.count(1)
68 """ Returns the list of pending task ids """
71 def schedule(self, task):
72 """ Add a task to the queue ordered by task.timestamp and arrival order
74 :param task: task to schedule
78 task.id = self._idgen.next()
80 entry = (task.timestamp, task.id, task)
81 self._valid.add(task.id)
82 heapq.heappush(self._queue, entry)
85 def remove(self, tid):
86 """ Remove a task form the queue
88 :param tid: Id of the task to be removed
93 self._valid.remove(tid)
98 """ Get the next task in the queue by timestamp and arrival order
102 timestamp, tid, task = heapq.heappop(self._queue)
103 if tid in self._valid: