1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395
|
#!/usr/bin/env python
"""SimulationStep 1.5.1
__version__ = '$Revision: 1.1.1.1.4.2 $ $Date: 2005/01/30 11:41:26 $ kgm'
LICENSE:
Copyright (C) 2002, 2005 Klaus G. Muller, Tony Vignaux
mailto: kgmuller@xs4all.nl and Tony.Vignaux@vuw.ac.nz
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
END OF LICENSE
Implements SimPy Processes, resources, and the backbone simulation scheduling
by coroutine calls.
Based on generators (Python 2.2 and later)
**Change history:**
Started out as SiPy 0.9
5/9/2002: SiPy 0.9.1
- Addition of '_cancel' method in class Process and supporting '_unpost' method in
class __Evlist.
- Removal of redundant 'Action' method in class Process.
12/9/2002:
- Addition of resource class
- Addition of "_request" and "_release" coroutine calls
15/9/2002: moved into SimPy package
16/9/2002:
- Resource attributes fully implemented (resources can now have more
than 1 shareable resource units)
17/9/2002:
- corrected removal from waitQ (Vignaux)
17/9/2002:
- added test for queue discipline in "test_demo()". Must be FIFO
26/9/02: Version 0.2.0
- cleaned up code; more consistent naming
- prefixed all Simulation-private variable names with "_".
- prefixed all class-private variable names with "__".
- made normal exit quiet (but return message from scheduler()
28/9/02:
- included stopSimulation()
15/10/02: Simulation version 0.3
- Version printout now only if __TESTING
- "_stop" initialized to True by module load, and set to False in
initialize()
- Introduced 'simulate(until=0)' instead of 'scheduler(till=0)'.
Left 'scheduler()' in for backward compatibility, but marked
as deprecated.
- Added attribute "name" to class Process; default=="a_process"
- Changed Resource constructor to
'def __init__(self,capacity=1,name="a_resource",unitName="units"'.
13/11/02: Simulation version 0.6
- Major changes to class Resource:
- Added two queue types for resources, FIFO (default) and PriorityQ
- Changed constructor to allow selection of queue type.
- Introduced preemption of resources (to be used with PriorityQ
queue type)
- Changed constructor of class Resource to allow selection of preemption
- Changes to class Process to support preemption of service
- Cleaned up 'simulate' by replacing series of if-statements by dispatch table.
19/11/02: Simulation version 0.6.1
- Changed priority schemes so that higher values of Process
attribute "priority" represent higher priority.
20/11/02: Simulation version 0.7
- Major change of priority approach:
- Priority set by "yield request,self,res,priority"
- Priority of a Process instance associated with a specific
resource
25/11/02: Simulation version 0.7.1
- Code cleanup and optimization
- Made process attributes remainService and preempted private
(_remainService and _preempted)
11/12/2002: First process interrupt implementation
- Addition of user methods 'interrupt' and 'resume'
- Significant code cleanup to maintain process state
20/12/2002: Changes to "interrupt"; addition of boolean methods to show
process states
16/3/2003: Changed hold (allowing posting events past _endtime)
18/3/2003: Changed _nextev to prevent _t going past _endtime
23/3/2003: Introduced new interrupt construct; deleted 'resume' method
25/3/2003: Expanded interrupt construct:
- Made 'interrupt' a method of Process
- Added 'interruptCause' as an attribute of an interrupted process
- Changed definition of 'active' to
'self._nextTime <> None and not self._inInterrupt'
- Cleaned up test_interrupt function
30/3/2003: Modification of 'simulate':
- error message if 'initialize' not called (fatal)
- error message if no process scheduled (warning)
- Ensured that upon exit from 'simulate', now() == _endtime is
always valid
2/04/2003:
- Modification of 'simulate': leave _endtime alone (undid change
of 30 Mar 03)
- faster '_unpost'
3/04/2003: Made 'priority' private ('_priority')
4/04/2003: Catch activation of non-generator error
5/04/2003: Added 'interruptReset()' function to Process.
7/04/2003: Changed '_unpost' to ensure that process has
_nextTime == None (is passive) afterwards.
8/04/2003: Changed _hold to allow for 'yield hold,self'
(equiv to 'yield hold,self,0')
10/04/2003: Changed 'cancel' syntax to 'Process().cancel(victim)'
12/5/2003: Changed eventlist handling from dictionary to bisect
9/6/2003: - Changed eventlist handling from pure dictionary to bisect-
sorted "timestamps" list of keys, resulting in greatly
improved performance for models with large
numbers of event notices with differing event times.
=========================================================
This great change was suggested by Prof. Simon Frost.
Thank you, Simon! This version 1.3 is dedicated to you!
=========================================================
- Added import of Lister which supports well-structured
printing of all attributes of Process and Resource instances.
9 Nov 2003: Added capability to step through simulation event by event.
November 2003: Brought up to Simulation 1.4alpha
13 Dec 2003: Merged in Monitor and Histogram
27 Feb 2004: Repaired bug in activeQ monitor of class Resource. Now actMon
correctly records departures from activeQ.
19 May 2004: Added erroneously omitted Histogram class.
5 Sep 2004: Added SimEvents synchronization constructs
17 Sep 2004: Added waituntil synchronization construct
01 Dec 2004: SimPy version 1.5
Changes in this module: Repaired SimEvents bug re proc.eventsFired
12 Jan 2005: SimPy version 1.5.1
Changes in this module: Monitor objects now have a default name
'a_Monitor'
"""
from __future__ import generators
from SimPy.Lister import *
import bisect
import types
__TESTING=False
__version__="1.5.1 February 2005"
if __TESTING: print "SimPy.SimulationStep %s" %__version__
hold=1234
passivate=5678
request=135
release=246
waitevent=4321
queueevent=8765
waituntil=999
_endtime=0
_t=0
_e=None
_stop=True
_wustep=False #controls per event stepping for waituntil construct; not for user API
True=1
False=0
paused=False
_step=False
condQ=[]
def initialize():
global _e,_t,_stop
_e=__Evlist()
_t=0
_stop=False
def now():
return _t
def stopSimulation():
"""Application function to stop simulation run"""
global _stop
_stop=True
def _startWUStepping():
"""Application function to start stepping through simulation for waituntil construct."""
global _wustep
_wustep=True
def _stopWUStepping():
"""Application function to stop stepping through simulation."""
global _wustep
_wustep=False
def startStepping():
"""Application function to start stepping through simulation."""
global _step
_step=True
def stopStepping():
"""Application function to stop stepping through simulation."""
global _step
_step=False
class Simerror(Exception):
def __init__(self,value):
self.value=value
def __str__(self):
return `self.value`
class Process(Lister):
"""Superclass of classes which may use generator functions"""
def __init__(self,name="a_process"):
#the reference to this Process instances single process (==generator)
self._nextpoint=None
self.name=name
self._nextTime=None #next activation time
self._remainService=0
self._preempted=0
self._priority={}
self._terminated=0
self._inInterrupt= False
self.eventsFired=[] #events waited/queued for occurred
def active(self):
return self._nextTime <> None and not self._inInterrupt
def passive(self):
return self._nextTime == None and not self._terminated
def terminated(self):
return self._terminated
def interrupted(self):
return self._inInterrupt and not self._terminated
def queuing(self,resource):
return self in resource.waitQ
def cancel(self,victim):
"""Application function to cancel all event notices for this Process instance;(should be all event
notices for the _generator_)."""
_e._unpost(whom=victim)
def _hold(self,a):
if len(a[0]) == 3:
delay=abs(a[0][2])
else:
delay=0
who=a[1]
self.interruptLeft=delay
self._inInterrupt=False
self.interruptCause=None
_e._post(what=who,at=_t+delay)
def _passivate(self,a):
a[0][1]._nextTime=None
def interrupt(self,victim):
"""Application function to interrupt active processes"""
# can't interrupt terminated/passive/interrupted process
if victim.active():
victim.interruptCause=self # self causes interrupt
left=victim._nextTime-_t
victim.interruptLeft=left # time left in current 'hold'
victim._inInterrupt=True
reactivate(victim)
return left
else: #victim not active -- can't interrupt
return None
def interruptReset(self):
"""
Application function for an interrupt victim to get out of
'interrupted' state.
"""
self._inInterrupt= False
def allEventNotices():
"""Returns string with eventlist as list of tuples (eventtime,action)"""
return `[(_e.events[i][0],[inst.who.name for inst in _e.events[1]]) \
for i in _e.events]`
class __Evlist:
"""Defines event list and operations on it"""
def __init__(self):
#has the structure {<time1>:(ev notice1, ev notice2, . . ),
# <time2>:(ev notice 3,...),..}
self.events={}
#always sorted list of event times (keys for self.events)
self.timestamps=[]
def _post(self,what,at,prior=False):
"""Post an event notice for process what for time at"""
# event notices are _Action instances
if at < _t:
raise SimError("Attempt to schedule event in the past")
if at in self.events:
if prior:
#before all other event notices at this time
self.events[at][0:0]= [what]
else:
self.events[at].append(what)
else: # first event notice at this time
self.events[at]=[what]
bisect.insort(self.timestamps,at)
what.who._nextTime=at
def _unpost(self,whom):
"""
Search through all event notices at whom's event time and remove whom's
event notice if whom is a suspended process
"""
thistime=whom._nextTime
if thistime == None: #check if whom was actually active
return
else:
thislist=self.events[thistime]
for n in thislist:
if n.who==whom:
self.events[thistime].remove(n)
whom._nextTime = None
if not self.events[thistime]:
# no other ev notices for thistime
del(self.events[thistime])
item_delete_point = bisect.bisect(self.timestamps,
thistime)
del self.timestamps[item_delete_point-1]
def _nextev(self):
"""Retrieve next event from event list"""
global _t, _stop
if not self.events: raise Simerror("No more events at time %s" %now())
earliest=self.timestamps[0]
_t=max(earliest,_t)
temp=self.events[earliest] #list of actions for this time _t
tempev=temp[0] #first action
del(self.events[earliest][0])
if self.events[earliest]==[]:
del(self.events[earliest]) #delete empty list of actions
del(self.timestamps[0])
if _t > _endtime:
_t = _endtime
_stop = True
return (None,)
try:
tt=tempev.who._nextpoint.next()
except StopIteration:
tempev.who._nextpoint=None
tempev.who._terminated=True
tempev.who._nextTime=None
tt=None
tempev=tempev.who
return tt,tempev
class _Action:
"""Structure (who=process owner, generator=process)"""
def __init__(self,who,generator):
self.who=who
self.process=generator
def __str__(self):
return "Action%s" %((self.who,self.process))
def activate(object,process,at="undefined",delay="undefined",prior=False):
"""Application function to activate passive process."""
if not (type(process) == types.GeneratorType):
raise Simerror("Fatal SimPy error: activating function which"+
" is not a generator (contains no 'yield')")
if not object._terminated and not object._nextTime:
#store generator reference in object; needed for reactivation
object._nextpoint=process
if at=="undefined":
at=_t
if delay=="undefined":
zeit=max(_t,at)
else:
zeit=max(_t,_t+delay)
_e._post(_Action(who=object,generator=process),at=zeit,prior=prior)
def reactivate(object,at="undefined",delay="undefined",prior=False):
"""Application function to reactivate a process which is active,
suspended or passive."""
# Object may be active, suspended or passive
if not object._terminated:
a=Process("SimPysystem")
a.cancel(object)
# object now passive
if at=="undefined":
at=_t
if delay=="undefined":
zeit=max(_t,at)
else:
zeit=max(_t,_t+delay)
_e._post(_Action(who=object,generator=object._nextpoint),at=zeit,
prior=prior)
class Queue(list):
def __init__(self,res,moni):
if moni==[]:
self.monit=True # True if Monitor
else:
self.monit=False
self.moni=moni # The Monitor
self.resource=res # the resource this queue belongs to
def enter(self,object):
pass
def leave(self):
pass
class FIFO(Queue):
def __init__(self,res,moni):
Queue.__init__(self,res,moni)
def enter(self,object):
self.append(object)
if self.monit:
self.moni.observe(len(self),t=now())
def leave(self):
a= self.pop(0)
if self.monit:
self.moni.observe(len(self),t=now())
return a
class PriorityQ(FIFO):
"""Queue is always ordered according to priority.
Higher value of priority attribute == higher priority.
"""
def __init__(self,res,moni):
FIFO.__init__(self,res,moni)
def enter(self,object):
if len(self):
ix=self.resource
if self[-1]._priority[ix] >= object._priority[ix]:
self.append(object)
else:
z=0
while self[z]._priority[ix] >= object._priority[ix]:
z += 1
self.insert(z,object)
else:
self.append(object)
if self.monit:
self.moni.observe(len(self),t=now())
class Resource(Lister):
"""Models shared, limited capacity resources with queuing;
FIFO is default queuing discipline.
"""
def __init__(self,capacity=1,name="a_resource",unitName="units",
qType=FIFO,preemptable=0,monitored=False):
self.name=name # resource name
self.capacity=capacity # resource units in this resource
self.unitName=unitName # type name of resource units
self.n=capacity # uncommitted resource units
self.monitored=monitored
if self.monitored: # Monitor waitQ, activeQ
self.actMon=Monitor(name="Active Queue Monitor %s"%self.name,
ylab="nr in queue",tlab="time")
monact=self.actMon
self.waitMon=Monitor(name="Wait Queue Monitor %s"%self.name,
ylab="nr in queue",tlab="time")
monwait=self.waitMon
else:
monwait=None
monact=None
self.waitQ=qType(self,monwait)
self.preemptable=preemptable
self.activeQ=qType(self,monact)
self.priority_default=0
def _request(self,arg):
"""Process request event for this resource"""
object=arg[1].who
if len(arg[0]) == 4: # yield request,self,resource,priority
object._priority[self]=arg[0][3]
else: # yield request,self,resource
object._priority[self]=self.priority_default
if self.preemptable and self.n == 0: # No free resource
# test for preemption condition
preempt=object._priority[self] > self.activeQ[-1]._priority[self]
# If yes:
if preempt:
z=self.activeQ[-1]
# suspend lowest priority process being served
suspended = z
# record remaining service time
z._remainService = z._nextTime - _t
Process().cancel(z)
# remove from activeQ
self.activeQ.remove(z)
# put into front of waitQ
self.waitQ.insert(0,z)
# record that it has been preempted
z._preempted = 1
# passivate re-queued process
z._nextTime=None
# assign resource unit to preemptor
self.activeQ.enter(object)
# post event notice for preempting process
_e._post(_Action(who=object,generator=object._nextpoint),
at=_t,prior=1)
else:
self.waitQ.enter(object)
# passivate queuing process
object._nextTime=None
else: # treat non-preemption case
if self.n == 0:
self.waitQ.enter(object)
# passivate queuing process
object._nextTime=None
else:
self.n -= 1
self.activeQ.enter(object)
_e._post(_Action(who=object,generator=object._nextpoint),
at=_t,prior=1)
def _release(self,arg):
"""Process release request for this resource"""
self.n += 1
self.activeQ.remove(arg[1].who)
if self.monitored:
self.actMon.observe(len(self.activeQ),t=now())
#reactivate first waiting requestor if any; assign Resource to it
if self.waitQ:
object=self.waitQ.leave()
self.n -= 1 #assign 1 resource unit to object
self.activeQ.enter(object)
# if resource preemptable:
if self.preemptable:
# if object had been preempted:
if object._preempted:
object._preempted = 0
# reactivate object delay= remaining service time
reactivate(object,delay=object._remainService)
# else reactivate right away
else:
reactivate(object,delay=0,prior=1)
# else:
else:
reactivate(object,delay=0,prior=1)
_e._post(_Action(who=arg[1].who,generator=arg[1].who._nextpoint),
at=_t,prior=1)
class SimEvent(Lister):
"""Supports one-shot signalling between processes. All processes waiting for an event to occur
get activated when its occurrence is signalled. From the processes queuing for an event, only
the first gets activated.
"""
def __init__(self,name="a_SimEvent"):
self.name=name
self.waits=[]
self.queues=[]
self.occurred=False
self.signalparam=None
def signal(self,param=None):
"""Produces a signal to self;
Fires this event (makes it occur).
Reactivates ALL processes waiting for this event. (Cleanup waits lists
of other events if wait was for an event-group (OR).)
Reactivates the first process for which all events they are queuing for
have fired. (Cleanup queues of other events if wait was for an event-group (OR).)
"""
self.signalparam=param
if not self.waits and not self.queues:
self.occurred=True
else:
#reactivate all waiting processes
for p in self.waits:
p[0].eventsFired.append(self)
reactivate(p[0])
#delete waits entries for this process in other events
for ev in p[1]:
if ev!=self:
if ev.occurred:
p[0].eventsFired.append(ev)
for iev in ev.waits:
if iev[0]==p[0]:
ev.waits.remove(iev)
break
self.waits=[]
if self.queues:
proc=self.queues.pop(0)[0]
proc.eventsFired.append(self)
reactivate(proc)
def _wait(self,par):
"""Consumes a signal if it has occurred, otherwise process 'proc'
waits for this event.
"""
proc=par[0][1] #the process issuing the yield waitevent command
proc.eventsFired=[]
if not self.occurred:
self.waits.append([proc,[self]])
proc._nextTime=None #passivate calling process
else:
proc.eventsFired.append(self)
self.occurred=False
_e._post(_Action(who=proc,generator=proc._nextpoint),
at=_t,prior=1)
def _waitOR(self,par):
"""Handles waiting for an OR of events in a tuple/list.
"""
proc=par[0][1]
evlist=par[0][2]
proc.eventsFired=[]
anyoccur=False
for ev in evlist:
if ev.occurred:
anyoccur=True
proc.eventsFired.append(ev)
ev.occurred=False
if anyoccur: #at least one event has fired; continue process
_e._post(_Action(who=proc,generator=proc._nextpoint),
at=_t,prior=1)
else: #no event in list has fired, enter process in all 'waits' lists
proc.eventsFired=[]
proc._nextTime=None #passivate calling process
for ev in evlist:
ev.waits.append([proc,evlist])
def _queue(self,par):
"""Consumes a signal if it has occurred, otherwise process 'proc'
queues for this event.
"""
proc=par[0][1] #the process issuing the yield queueevent command
proc.eventsFired=[]
if not self.occurred:
self.queues.append([proc,[self]])
proc._nextTime=None #passivate calling process
else:
proc.eventsFired.append(self)
self.occurred=False
_e._post(_Action(who=proc,generator=proc._nextpoint),
at=_t,prior=1)
def _queueOR(self,par):
"""Handles queueing for an OR of events in a tuple/list.
"""
proc=par[0][1]
evlist=par[0][2]
proc.eventsFired=[]
anyoccur=False
for ev in evlist:
if ev.occurred:
anyoccur=True
proc.eventsFired.append(ev)
ev.occurred=False
if anyoccur: #at least one event has fired; continue process
_e._post(_Action(who=proc,generator=proc._nextpoint),
at=_t,prior=1)
else: #no event in list has fired, enter process in all 'waits' lists
proc.eventsFired=[]
proc._nextTime=None #passivate calling process
for ev in evlist:
ev.queues.append([proc,evlist])
## begin waituntil functionality
def _test():
"""
Gets called by simulate after every event, as long as there are processes
waiting in condQ for a condition to be satisfied.
Tests the conditions for all waiting processes. Where condition satisfied,
reactivates that process immediately and removes it from queue.
"""
global condQ
rList=[]
for el in condQ:
if el.cond():
rList.append(el)
reactivate(el)
for i in rList:
condQ.remove(i)
if not condQ:
_stopWUStepping()
def _waitUntilFunc(proc,cond):
global condQ
"""
Puts a process 'proc' waiting for a condition into a waiting queue.
'cond' is a predicate function which returns True if the condition is
satisfied.
"""
if not cond():
condQ.append(proc)
proc.cond=cond
_startWUStepping() #signal 'simulate' that a process is waiting
# passivate calling process
proc._nextTime=None
else:
#schedule continuation of calling process
_e._post(_Action(who=proc,generator=proc._nextpoint),
at=_t,prior=1)
##end waituntil functionality
def scheduler(till=0):
"""Schedules Processes/semi-coroutines until time 'till'.
Deprecated since version 0.5.
"""
simulate(until=till)
def holdfunc(a):
a[0][1]._hold(a)
def requestfunc(a):
a[0][2]._request(a)
def releasefunc(a):
a[0][2]._release(a)
def passivatefunc(a):
a[0][1]._passivate(a)
def waitevfunc(a):
#if waiting for one event only (not a tuple or list)
evtpar=a[0][2]
if isinstance(evtpar,SimEvent):
a[0][2]._wait(a)
# else, if waiting for an OR of events (list/tuple):
else: #it should be a list/tuple of events
# call _waitOR for first event
evtpar[0]._waitOR(a)
def queueevfunc(a):
#if queueing for one event only (not a tuple or list)
evtpar=a[0][2]
if isinstance(evtpar,SimEvent):
a[0][2]._queue(a)
#else, if queueing for an OR of events (list/tuple):
else: #it should be a list/tuple of events
# call _queueOR for first event
evtpar[0]._queueOR(a)
def waituntilfunc(par):
_waitUntilFunc(par[0][1],par[0][2])
def simulate(callback=lambda :None,until=0):
"""Schedules Processes/semi-coroutines until time 'until'"""
"""Gets called once. Afterwards, co-routines (generators) return by
'yield' with a cargo:
yield hold, self, <delay>: schedules the "self" process for activation
after <delay> time units.If <,delay> missing,
same as "yield hold,self,0"
yield passivate,self : makes the "self" process wait to be re-activated
yield request,self,<Resource> : request 1 unit from <Resource>.
yield release,self,<Resource> : release 1 unit to <Resource>
yield waitevent,self,<SimEvent>|[<Evt1>,<Evt2>,<Evt3), . . . ]:
wait for one or more of several events
yield queueevent,self,<SimEvent>|[<Evt1>,<Evt2>,<Evt3), . . . ]:
queue for one or more of several events
yield waituntil,self,cond : wait for arbitrary condition
Event notices get posted in event-list by scheduler after "yield" or by
"activate"/"reactivate" functions.
Nov 9, 2003: Added capability to step through simulation event by event if
step==True. 'callback' gets called after every event. It can
cancel stepping or end run. API and semantics backwards
compatible with previous versions of simulate().
"""
global _endtime,_e,_stop,_t,_step,_wustep
paused=False
_stop=False
if _e == None:
raise Simerror("Fatal SimPy error: Simulation not initialized")
if _e.events == {}:
message="SimPy: No activities scheduled"
return message
_endtime=until
message="SimPy: Normal exit"
dispatch={hold:holdfunc,request:requestfunc,release:releasefunc,
passivate:passivatefunc,waitevent:waitevfunc,queueevent:queueevfunc,
waituntil:waituntilfunc}
while not _stop and _t<=_endtime:
try:
a=_e._nextev()
if not a[0]==None:
command = a[0][0]
dispatch[command](a)
except Simerror, error:
message="SimPy: "+ error.value
_stop = True
if _step:
callback()
if _wustep:
_test()
_stopWUStepping()
stopStepping()
_e=None
return message
def simulateStep(callback=lambda :None,until=0):
"""Schedules Processes/semi-coroutines until next event"""
"""Can be called repeatedly.
Behaves like "simulate", but does execute only one event per call.
"""
global _endtime,_e,_stop,_t,_step
status="resumable"
if _e == None:
raise Simerror("Fatal SimPy error: Simulation not initialized")
if _e.events == {}:
message="SimPy: No activities scheduled"
status="notResumable"
return message,status
_endtime=until
message="SimPy: Normal exit"
dispatch={hold:holdfunc,request:requestfunc,release:releasefunc,
passivate:passivatefunc}
if not _stop and _t<=_endtime:
try:
a=_e._nextev()
if not a[0]==None:
command = a[0][0]
dispatch[command](a)
except Simerror, error:
message="SimPy: "+ error.value
_stop = True
status="notResumable"
if _step:
callback()
return message,status
class Histogram(list):
""" A histogram gathering and sampling class"""
def __init__(self,name = '',low=0.0,high=100.0,nbins=10):
list.__init__(self)
self.name = name
self.low = low
self.high = high
self.nbins = nbins
self.binsize=(self.high-self.low)/nbins
#self[:] = [[1,2],[3,4]]
self[:] =[[low+(i-1)*self.binsize,0] for i in range(self.nbins+2)]
#print '__init__ :', self[0],self
def addIn(self,y):
""" add a value into the correct bin"""
b = int((y-self.low+self.binsize)/self.binsize)
if b < 0: b = 0
if b > self.nbins+1: b = self.nbins+1
assert 0 <= b <=self.nbins+1,'Histogram.addIn: b out of range: %s'%b
self[b][1]+=1
class Monitor(list):
""" Monitored variables
A Class for monitored variables, that is, variables that allow one
to gather simple statistics. A Monitor is a subclass of list and
list operations can be performed on it. An object is established
using m= Monitor(name = '..'). It can be given a
unique name for use in debugging and in tracing and ylab and tlab
strings for labelling graphs.
"""
def __init__(self,name='a_Monitor',ylab='y',tlab='t'):
list.__init__(self)
self.startTime = 0.0
self.name = name
self.ylab = ylab
self.tlab = tlab
def observe(self,y,t=None):
"""record y and t"""
if t is None: t = now()
self.append([t,y])
def tally(self,y):
""" deprecated: tally for backward compatibility"""
self.observe(y,0)
def accum(self,y,t=None):
""" deprecated: accum for backward compatibility"""
self.observe(y,t)
def reset(self,t=None):
"""reset the sums and counts for the monitored variable """
self[:]=[]
if t is None: t = now()
self.startTime = t
def tseries(self):
""" the series of measured times"""
return list(zip(*self)[0])
def yseries(self):
""" the series of measured values"""
return list(zip(*self)[1])
def count(self):
""" deprecated: the number of observations made """
return self.__len__()
def total(self):
""" the sum of the y"""
if self.__len__()==0: return 0
else:
sum = 0.0
for i in range(self.__len__()):
sum += self[i][1]
return sum # replace by sum() later
def mean(self):
""" the simple average of the monitored variable"""
try: return 1.0*self.total()/self.__len__()
except: print 'SimPy: No observations for mean'
def var(self):
""" the sample variance of the monitored variable """
n = len(self)
tot = self.total()
ssq=0.0
yy = self.yseries()
for i in range(self.__len__()):
ssq += self[i][1]**2 # replace by sum() eventually
try: return (ssq - float(tot*tot)/n)/n
except: print 'SimPy: No observations for sample variance'
def timeAverage(self,t=None):
""" the time-average of the monitored variable.
If t is used it is assumed to be the current time,
otherwise t = now()
"""
N = self.__len__()
if N == 0:
print 'SimPy: No observations for timeAverage'
return None
if t == None: t = now()
sum = 0.0
tlast = self.startTime
#print 'DEBUG: timave ',t,tlast
ylast = 0.0
for i in range(N):
ti,yi = self[i]
sum += ylast*(ti-tlast)
tlast = ti
ylast = yi
sum += ylast*(t-tlast)
T = t - self.startTime
if T == 0:
print 'SimPy: No elapsed time for timeAverage'
return None
#print 'DEBUG: timave ',sum,t,T
return sum/float(T)
def histogram(self,low=0.0,high=100.0,nbins=10):
""" A histogram of the monitored y data values.
"""
h = Histogram(name=self.name,low=low,high=high,nbins=nbins)
ys = self.yseries()
for y in ys: h.addIn(y)
return h
################### end of Simulation module
################### start of test/demo programs
def askCancel():
a=raw_input("[Time=%s] End run (e), Continue stepping (s), Run to end (r)"%now())
if a=="e":
stopSimulation()
elif a=="s":
return
else:
stopStepping()
def test_demo():
class Aa(Process):
sequIn=[]
sequOut=[]
def __init__(self,holdtime,name):
Process.__init__(self,name)
self.holdtime=holdtime
def life(self,priority):
for i in range(1):
Aa.sequIn.append(self.name)
print now(),rrr.name,"waitQ:",len(rrr.waitQ),"activeQ:",\
len(rrr.activeQ)
print "waitQ: ",[(k.name,k._priority[rrr]) for k in rrr.waitQ]
print "activeQ: ",[(k.name,k._priority[rrr]) \
for k in rrr.activeQ]
assert rrr.n+len(rrr.activeQ)==rrr.capacity, \
"Inconsistent resource unit numbers"
print now(),self.name,"requests 1 ", rrr.unitName
yield request,self,rrr,priority
print now(),self.name,"has 1 ",rrr.unitName
print now(),rrr.name,"waitQ:",len(rrr.waitQ),"activeQ:",\
len(rrr.activeQ)
print now(),rrr.name,"waitQ:",len(rrr.waitQ),"activeQ:",\
len(rrr.activeQ)
assert rrr.n+len(rrr.activeQ)==rrr.capacity, \
"Inconsistent resource unit numbers"
yield hold,self,self.holdtime
print now(),self.name,"gives up 1",rrr.unitName
yield release,self,rrr
Aa.sequOut.append(self.name)
print now(),self.name,"has released 1 ",rrr.unitName
print "waitQ: ",[(k.name,k._priority[rrr]) for k in rrr.waitQ]
print now(),rrr.name,"waitQ:",len(rrr.waitQ),"activeQ:",\
len(rrr.activeQ)
assert rrr.n+len(rrr.activeQ)==rrr.capacity, \
"Inconsistent resource unit numbers"
class Destroyer(Process):
def __init__(self):
Process.__init__(self)
def destroy(self,whichProcesses):
for i in whichProcesses:
Process().cancel(i)
yield hold,self,0
class Observer(Process):
def __init__(self):
Process.__init__(self)
def observe(self,step,processes,res):
while now()<11:
for i in processes:
print " %s %s: act:%s, pass:%s, term: %s,interr:%s, qu:%s"\
%(now(),i.name,i.active(),i.passive(),i.terminated()\
,i.interrupted(),i.queuing(res))
print
yield hold,self,step
class UserControl(Process):
def letUserInteract(self,when):
yield hold,self,when
startStepping()
print "****First case == priority queue, resource service not preemptable"
initialize()
rrr=Resource(5,name="Parking",unitName="space(s)", qType=PriorityQ,
preemptable=0)
procs=[]
for i in range(10):
z=Aa(holdtime=i,name="Car "+str(i))
procs.append(z)
activate(z,z.life(priority=i))
o=Observer()
activate(o,o.observe(1,procs,rrr))
startStepping()
a=simulate(until=10000,callback=askCancel)
print "Input sequence: ",Aa.sequIn
print "Output sequence: ",Aa.sequOut
print "\n****Second case == priority queue, resource service preemptable"
initialize()
rrr=Resource(5,name="Parking",unitName="space(s)", qType=PriorityQ,
preemptable=1)
procs=[]
for i in range(10):
z=Aa(holdtime=i,name="Car "+str(i))
procs.append(z)
activate(z,z.life(priority=i))
o=Observer()
activate(o,o.observe(1,procs,rrr))
u=UserControl()
activate(u,u.letUserInteract(4))
Aa.sequIn=[]
Aa.sequOut=[]
a=simulate(askCancel,until=10000)
print a
print "Input sequence: ",Aa.sequIn
print "Output sequence: ",Aa.sequOut
def test_interrupt():
class Bus(Process):
def __init__(self,name):
Process.__init__(self,name)
def operate(self,repairduration=0):
print now(),">> %s starts" %(self.name)
tripleft = 1000
while tripleft > 0:
yield hold,self,tripleft
if self.interrupted():
print "interrupted by %s" %self.interruptCause.name
print "%s: %s breaks down " %(now(),self.name)
tripleft=self.interruptLeft
self.interruptReset()
print "tripleft ",tripleft
reactivate(br,delay=repairduration) # breakdowns only during operation
yield hold,self,repairduration
print now()," repaired"
else:
break # no breakdown, ergo bus arrived
print now(),"<< %s done" %(self.name)
class Breakdown(Process):
def __init__(self,myBus):
Process.__init__(self,name="Breakdown "+myBus.name)
self.bus=myBus
def breakBus(self,interval):
while True:
yield hold,self,interval
if self.bus.terminated(): break
self.interrupt(self.bus)
print"\n\n+++test_interrupt"
initialize()
b=Bus("Bus 1")
activate(b,b.operate(repairduration=20))
br=Breakdown(b)
activate(br,br.breakBus(200))
startStepping()
simulate(until=4000)
def testSimEvents():
class Waiter(Process):
def waiting(self,theSignal):
while True:
yield waitevent,self,theSignal
print "%s: process '%s' continued after waiting for %s"%(now(),self.name,theSignal.name)
yield queueevent,self,theSignal
print "%s: process '%s' continued after queueing for %s"%(now(),self.name,theSignal.name)
class ORWaiter(Process):
def waiting(self,signals):
while True:
yield waitevent,self,signals
print now(),"one of %s signals occurred"%[x.name for x in signals]
print "\t%s (fired/param)"%[(x.name,x.signalparam) for x in self.eventsFired]
yield hold,self,1
class Caller(Process):
def calling(self):
while True:
signal1.signal("wake up!")
print "%s: signal 1 has occurred"%now()
yield hold,self,10
signal2.signal("and again")
signal2.signal("sig 2 again")
print "%s: signal1, signal2 have occurred"%now()
yield hold,self,10
print"\n+++testSimEvents output"
initialize()
signal1=SimEvent("signal 1")
signal2=SimEvent("signal 2")
signal1.signal("startup1")
signal2.signal("startup2")
w1=Waiter("waiting for signal 1")
activate(w1,w1.waiting(signal1))
w2=Waiter("waiting for signal 2")
activate(w2,w2.waiting(signal2))
w3=Waiter("also waiting for signal 2")
activate(w3,w3.waiting(signal2))
w4=ORWaiter("waiting for either signal 1 or signal 2")
activate(w4,w4.waiting([signal1,signal2]),prior=True)
c=Caller("Caller")
activate(c,c.calling())
print simulate(until=100)
def testwaituntil():
"""
Demo of waitUntil capability.
Scenario:
Three workers require sets of tools to do their jobs. Tools are shared, scarce
resources for which they compete.
"""
import random
class Worker(Process):
def __init__(self,name,heNeeds=[]):
Process.__init__(self,name)
self.heNeeds=heNeeds
def work(self):
def workerNeeds():
for item in self.heNeeds:
if item.n==0:
return False
return True
while now()<8*60:
yield waituntil,self,workerNeeds
for item in self.heNeeds:
yield request,self,item
print "%s %s has %s and starts job" %(now(),self.name,
[x.name for x in self.heNeeds])
yield hold,self,random.uniform(10,30)
for item in self.heNeeds:
yield release,self,item
yield hold,self,2 #rest
print "\n+++ nwaituntil demo output"
initialize()
brush=Resource(capacity=1,name="brush")
ladder=Resource(capacity=2,name="ladder")
hammer=Resource(capacity=1,name="hammer")
saw=Resource(capacity=1,name="saw")
painter=Worker("painter",[brush,ladder])
activate(painter,painter.work())
roofer=Worker("roofer",[hammer,ladder,ladder])
activate(roofer,roofer.work())
treeguy=Worker("treeguy",[saw,ladder])
activate(treeguy,treeguy.work())
for who in (painter,roofer,treeguy):
print "%s needs %s for his job" %(who.name,[x.name for x in who.heNeeds])
print
print simulate(until=9*60)
if __name__ == "__main__":
print "SimPy.SimulationStep %s" %__version__
test_demo()
test_interrupt()
testSimEvents()
testwaituntil()
|