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 as published by
7 # the Free Software Foundation, either version 3 of the License, or
8 # (at your option) any later version.
10 # This program is distributed in the hope that it will be useful,
11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 # GNU General Public License for more details.
15 # You should have received a copy of the GNU General Public License
16 # along with this program. If not, see <http://www.gnu.org/licenses/>.
18 # Author: Alina Quereilhac <alina.quereilhac@inria.fr>
30 """ This class is to define a task, that is represented by an id,
31 an execution time 'timestamp' and an action 'callback """
33 def __init__(self, timestamp, callback):
35 self.timestamp = timestamp
36 self.callback = callback
38 self.status = TaskStatus.NEW
40 class HeapScheduler(object):
41 """ Create a Heap Scheduler.
45 This class is thread safe.
46 All calls to C Extensions are made atomic by the GIL in the CPython implementation.
47 heapq.heappush, heapq.heappop, and list access are therefore thread-safe.
52 super(HeapScheduler, self).__init__()
55 self._idgen = itertools.count(1)
57 def schedule(self, task):
58 """ Add the task 'task' in the heap of the scheduler
60 :param task: task that need to be schedule
64 task.id = self._idgen.next()
65 entry = (task.timestamp, task.id, task)
66 self._valid.add(task.id)
67 heapq.heappush(self._queue, entry)
70 def remove(self, tid):
71 """ Remove a task form the heap
73 :param tid: Id of the task that need to be removed
77 self._valid.remove(tid)
82 """ Get the next task in the scheduler
87 timestamp, tid, task = heapq.heappop(self._queue)
88 if tid in self._valid: