sgpemv2/plugins/pyloader/src/builtin-policies/lottery.py
tchernobog ad774067e1 - Add lottery and plain round robin cpu policies. I didn't test
them extensively, mind you. Closes task #14.
- Added documentation for each cpu policy
- Manage extra-exception into PythonCPUPolicy (when the .py
file doesn't contain a similarly named class)
- Update exception output in GuiBuilder to make it slightly
more descriptive


git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@983 3ecf2c5c-341e-0410-92b4-d18e462d057c
2006-09-01 17:03:34 +00:00

49 lines
1.5 KiB
Python

# src/builtin-policies/lottery.py - Copyright 2005, 2006, University
# of Padova, dept. of Pure and Applied
# Mathematics
#
# This file is part of SGPEMv2.
#
# This is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# SGPEMv2 is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with SGPEMv2; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
from CPUPolicy import CPUPolicy
from random import randint
class lottery(CPUPolicy) :
"""Lottery scheduling
Every time slice, a thread will be selected from the ready
queue by random. This policy does not pre-empt before the
end of the time slice."""
def __init__(self):
pass;
def configure(self):
param = self.get_parameters()
param.register_int("Time slice", 1, 10000, True, 2)
def is_preemptive(self):
return False
def get_time_slice(self):
return self.get_parameters().get_int("Time slice")
def sort_queue(self, queue):
sz = queue.size()
if(sz > 0):
queue.swap(0, randint(0, sz - 1))