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>
24 """ Execution state of the Task
31 """ A Task represents an operation to be executed by the
32 ExperimentController scheduler
35 def __init__(self, timestamp, callback):
37 :param timestamp: Future execution date of the operation
40 :param callback: A function to invoke in order to execute the operation
41 :type callback: function
45 self.timestamp = timestamp
46 self.callback = callback
48 self.status = TaskStatus.NEW
50 class HeapScheduler(object):
51 """ Create a Heap Scheduler
55 This class is thread safe.
56 All calls to C Extensions are made atomic by the GIL in the CPython implementation.
57 heapq.heappush, heapq.heappop, and list access are therefore thread-safe.
62 super(HeapScheduler, self).__init__()
65 self._idgen = itertools.count(1)
69 """ Returns the list of pending task ids """
72 def schedule(self, task):
73 """ Add a task to the queue ordered by task.timestamp and arrival order
75 :param task: task to schedule
79 task.id = self._idgen.next()
81 entry = (task.timestamp, task.id, task)
82 self._valid.add(task.id)
83 heapq.heappush(self._queue, entry)
86 def remove(self, tid):
87 """ Remove a task form the queue
89 :param tid: Id of the task to be removed
94 self._valid.remove(tid)
99 """ Get the next task in the queue by timestamp and arrival order
103 timestamp, tid, task = heapq.heappop(self._queue)
104 if tid in self._valid: