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 | ------------------------------------------------------------------------------
-- --
-- POSIX.5b VALIDATION TEST SUITE --
-- --
-- P 9 9 0 0 x 0 --
-- --
-- B o d y --
-- --
-- --
-- Copyright (c) 1998 Florida State University (FSU). All Rights --
-- Reserved. --
-- --
-- This is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free --
-- Software Foundation; either version 2, or (at your option) any later --
-- version. This software 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 distributed with GNARL; see --
-- file COPYING. If not, write to the Free Software Foundation, 59 --
-- Temple Place - Suite 330, Boston, MA 02111-1307, USA. --
-- --
-- Under contract GS-35F-4506G, the U. S. Government obtained unlimited --
-- rights in the software and documentation contained herein. Unlimited --
-- rights are defined in DFAR 252,227-7013(a)(19). By making this public --
-- release, the Government intends to confer upon all recipients --
-- unlimited rights equal to those held by the Government. These rights --
-- include rights to use, duplicate, release or disclose the released --
-- data an computer software in whole or in part, in any manner and for --
-- any purpose whatsoever, and to have or permit others to do so. --
-- --
-- DISCLAIMER -- ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE --
-- AVAILABLE OR DISCLOSED ARE AS IS. THE GOVERNMENT MAKES NO EXPRESS OR --
-- IMPLIED WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS --
-- OF THE SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE --
-- AVAILABLE OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS --
-- FOR A PARTICULAR PURPOSE OF SAID MATERIAL. --
-- --
------------------------------------------------------------------------------
-- [$Revision: 1.4 $]
-- Simulate mix of periodic jobs with rate monotone priorities.
with Calendar,
Ada.Real_Time,
POSIX,
POSIX_Calendar,
POSIX_Process_Identification,
POSIX_Process_Primitives,
POSIX_Process_Scheduling,
POSIX_Report,
POSIX_Timers,
System,
P9900doc,
P990000;
package body P9900x0 is
use P990000,
POSIX,
POSIX_Process_Identification,
POSIX_Process_Primitives,
POSIX_Process_Scheduling,
POSIX_Report;
Data : Shared_Data_Ptr;
-- Initialized in each main procedure.
-- For versions that use multiple processes, we also need to
-- set the process priority, elsewhere.
procedure Compute_Loads (Load_Factor : Positive);
procedure Find_Utilization_Limit;
procedure Start_Tasks;
procedure Stop_Tasks;
procedure Start_Processes;
procedure Stop_Processes;
procedure Work (Job : Jobs);
-- Implements the body of periodic task.
function Run_Jobs return Boolean;
procedure Compute_Loads (Load_Factor : Positive) is
begin
Data.Input_Load (1) := 1;
for J in Jobs loop
Data.Input_Load (J) :=
Integer (Float (Load_Factor) * Input_Time (J));
Data.Output_Load (J) :=
Integer (Float (Load_Factor) * Output_Time (J));
Data.Computation_Load (J) :=
Integer (Float (Load_Factor) * Computation_Time (J));
end loop;
exception when E : others => Fatal_Exception (E, "A001: P9900x0");
end Compute_Loads;
procedure Work (Job : Jobs) is
begin
Await_Start;
loop
Do_Input (Data.Input_Load (Job));
Do_Computation (Data.Computation_Load (Job));
Do_Output (Data.Output_Load (Job));
exit when not Reschedule (Job);
end loop;
Done_Job;
exception
when E : others =>
Done_Job;
Fatal_Exception (E, "A002: P9900x0");
end Work;
function Run_Jobs return Boolean is
begin
Data.Missed_Deadlines := False;
Initialize_Sync;
if Jobs_Are_Processes then
Start_Processes;
Data.Start_POSIX_Time := POSIX_Calendar.Clock;
Data.Start_Calendar_Time := Calendar.Clock;
Data.Start_Real_Time := Ada.Real_Time.Clock;
if Needs_Clock_Realtime then
Data.Start_Timespec :=
POSIX_Timers.Get_Time (POSIX_Timers.Clock_Realtime);
end if;
Initialize_Scheduling (Data);
Start_All_Jobs;
Await_All_Jobs_Done;
Stop_Processes;
else
Start_Tasks;
Data.Start_POSIX_Time := POSIX_Calendar.Clock;
Data.Start_Calendar_Time := Calendar.Clock;
Data.Start_Real_Time := Ada.Real_Time.Clock;
if Needs_Clock_Realtime then
Data.Start_Timespec :=
POSIX_Timers.Get_Time (POSIX_Timers.Clock_Realtime);
end if;
Initialize_Scheduling (Data);
Start_All_Jobs;
Await_All_Jobs_Done;
Stop_Tasks;
end if;
Finalize_Scheduling;
return not Data.Missed_Deadlines;
exception
when E : others =>
Finalize_Scheduling;
Fatal_Exception (E, "A003: P9900x0");
return not Data.Missed_Deadlines;
end Run_Jobs;
procedure Find_Utilization_Limit is
use Calendar;
T1, T2 : Time;
Clock_Resolution_Bound, D, Base : Duration;
K, Hi, Lo, Load_Factor : Integer;
Total_Utilization,
Unit_Work_Execution_Time : Float;
begin
-- Compute job periods and estimate total utilization.
Total_Utilization := 0.0;
for J in Jobs loop
Total_Utilization := Total_Utilization +
(Input_Time (J) + Computation_Time (J) + Output_Time (J))
* float (Rate (J));
end loop;
-- Estimate resolution of Calendar.Clock.
Clock_Resolution_Bound := 100.0;
for I in 1 .. 1000 loop
T1 := Clock;
loop
T2 := Clock;
D := T2 - T1;
exit when D > 0.0;
T1 := T2;
end loop;
if D < Clock_Resolution_Bound then
Clock_Resolution_Bound := D;
end if;
end loop;
Comment ("using clock resolution bound of" &
Integer'Image (Integer (D * 1_000_000)) & "us");
-- Use Calendar.Clock to measure execution time of
-- procedure P990000.Do_Unit_Work, to a number of decimal
-- digits specified by the constant Real_Accuracy.
-- Use dual-loop benchmark method.
K := 10000;
loop
T1 := Clock;
for J in 1 .. K loop
P990000.Do_Unit_Work (J);
end loop;
T2 := Clock;
Base := T2 - T1;
exit when Base > Real_Accuracy * Clock_Resolution_Bound;
K := K * 10;
end loop;
T1 := Clock;
for J in 1 .. K loop
P990000.Do_Unit_Work (J);
P990000.Do_Unit_Work (J);
end loop;
T2 := Clock;
D := (T2 - T1) - Base;
Unit_Work_Execution_Time := Float (D) / Float (K);
Comment ("unit_work computation time",
To_Timespec (Duration (Unit_Work_Execution_Time)));
-- Initialize lower and upper bounds on achievable
-- load factor, before bisection.
-- Upper bound (Hi) must be high enough to cause failure.
Lo := 1;
Comment ("finding a breakdown load factor");
Hi := 1;
loop
Compute_Loads (Hi);
if Run_Jobs then
Lo := Hi;
Comment ("underloaded at " & Integer'Image (Hi));
Hi := Hi * 16;
else
Comment ("overloaded at " & Integer'Image (Hi));
exit;
end if;
end loop;
-- Zero in on maximum workable load factor, by bisection.
Comment ("using bisection to find limiting load factor");
loop
Load_Factor := (Lo + Hi) / 2;
-- Lo <= Load_Factor < Hi
Compute_Loads (Load_Factor);
if Run_Jobs then
Lo := Load_Factor;
Comment ("underloaded at " & Integer'Image (Load_Factor));
else
Hi := Load_Factor;
Comment ("overloaded at " & Integer'Image (Load_Factor));
end if;
exit when Hi - Lo <= (Load_Factor + Accuracy) / Accuracy;
end loop;
Comment ("limiting load factor =" & Integer'Image (Load_Factor));
-- Compute actual effective utilization.
Total_Utilization := 0.0;
for J in Jobs loop
Total_Utilization := Total_Utilization +
Float ((Data.Input_Load (J) + Data.Output_Load (J)
+ Data.Computation_Load (J))
* Rate (J)) * Unit_Work_Execution_Time;
end loop;
Comment ("apparent limit utilization =" &
Integer'Image (Integer (Total_Utilization * 100.0)) & "%");
exception when E : others => Fatal_Exception (E, "A004: P9900x0");
end Find_Utilization_Limit;
task type Periodic_Task
(Job : Jobs) is
pragma Priority (Priority (Job));
end Periodic_Task;
type Periodic_Task_Ptr is access all Periodic_Task;
task body Periodic_Task is
begin
Work (Job);
end Periodic_Task;
Periodic_Tasks : array (Jobs) of Periodic_Task_Ptr;
procedure Start_Tasks is
begin
for J in Jobs loop
Periodic_Tasks (J) :=
new Periodic_Task (J);
end loop;
exception
when E : others => Fatal_Exception (E, "A005: P9900x0: in Start_Jobs");
end Start_Tasks;
procedure Stop_Tasks is
begin
for J in Jobs loop
if not Periodic_Tasks (J).all'Terminated then
abort Periodic_Tasks (J).all;
end if;
end loop;
exception
when E : others => Fatal_Exception (E, "A006: P9900x0: in Stop_Jobs");
end Stop_Tasks;
Status : Termination_Status;
Periodic_Processes : array (Jobs) of Process_ID;
procedure Start_Processes is
Child_Pathname : constant POSIX.Pathname :=
"p9900" & To_POSIX_String (Version) & "b";
Template : Process_Template;
Args : POSIX_String_List;
Parms : Scheduling_Parameters;
Max_Prio : constant Scheduling_Priority :=
Get_Maximum_Priority (Sched_FIFO);
Min_Prio : constant Scheduling_Priority :=
Get_Minimum_Priority (Sched_FIFO);
Num_Jobs : constant Integer := Jobs'Last - Jobs'First + 1;
function Process_Prio
(Prio : System.Priority) return Scheduling_Priority;
function Process_Prio
(Prio : System.Priority) return Scheduling_Priority is
-- In System.Priority, higher numbers are higher priorities;
-- so also for Scheduling_Priority values.
begin
return Scheduling_Priority
(Max_Prio - (System.Priority'Last - Prio));
end Process_Prio;
begin
-- set main process's priority to the maximum
Assert (Integer
(Max_Prio - Min_Prio + 1) >= Num_Jobs + 1, "A007: P9900x0");
Comment ("min_prio = " & Scheduling_Priority'Image (Min_Prio));
Comment ("max_prio = " & Scheduling_Priority'Image (Max_Prio));
Comment ("num_jobs = " & Jobs'Image (Num_Jobs));
begin
Comment ("priority = " & Scheduling_Priority'Image
(Process_Prio (System.Priority'Last)));
exception when E : others =>
Unexpected_Exception (E, "A008: P9900x0: in Run_Jobs/Set_Priority");
raise POSIX_Error;
end;
begin
Comment ("Set_Priority to system.Priority'last");
Set_Priority (Parms, Process_Prio (System.Priority'Last));
exception
when E: others =>
Unexpected_Exception (E, "A009: P9900x0: in Run_Jobs/Set_Priority");
raise POSIX_Error;
end;
Comment ("setting scheduling policy");
begin
null;
Set_Scheduling_Policy (Process => Get_Process_ID,
New_Policy => Sched_FIFO,
Parameters => Parms);
exception
when E1 : POSIX_Error =>
Privileged (Realtime_Process_Priority_Privilege,
Priority_Process_Scheduling_Option,
Operation_Not_Permitted, E1, "A010: P9900x0");
when E2 : others => Unexpected_Exception
(E2, "A011: P9900x0: in Run_Jobs/Set_Sched_Policy");
raise POSIX_Error;
end;
Open_Template (Template);
-- create the periodic processes
for J in Jobs loop
Make_Empty (Args);
POSIX.Append (Args, Child_Pathname);
Pass_Through_Verbosity (Args);
POSIX.Append (Args, "-child" & To_POSIX_String (Jobs'Image (J)));
Start_Process (Child => Periodic_Processes (J),
Pathname => Child_Pathname,
Template => Template,
Arg_List => Args);
Set_Priority (Parms, Process_Prio (Priority (J)));
Set_Scheduling_Policy (Process => Periodic_Processes (J),
New_Policy => Sched_FIFO,
Parameters => Parms);
Wait_For_Child_Process
(Status => Status,
Child => Periodic_Processes (J),
Block => False);
Assert (not Status_Available (Status), "A012: P9900x0");
end loop;
exception
when E : others => Fatal_Exception (E, "A013: P9900x0: Start_Jobs");
end Start_Processes;
procedure Stop_Processes is
begin
for J in Jobs loop
Wait_For_Child_Process
(Status => Status,
Child => Periodic_Processes (J));
Check_Child_Status
(Status => Status,
Child_ID => Periodic_Processes (J),
Expected => 0,
Message => "A014: P9900x0");
end loop;
exception
when E : others => Fatal_Exception (E, "A015: P9900x0: Stop_Jobs");
end Stop_Processes;
procedure Parent_Main is
task Main is
pragma Priority (Main_Priority);
end Main;
task body Main is
begin
Header ("P9900" & Version, Root_OK => True);
Optional (Priority_Process_Scheduling_Option, "A016: P9900x0");
if Needs_Clock_Realtime then
Optional (Timers_Option, "P9900x0");
end if;
Data := Shared_Data;
Find_Utilization_Limit;
Done;
exception when E : others => Fatal_Exception (E, "A017: P9900x0");
end Main;
begin
while not Main'Terminated loop
delay 1.0;
end loop;
Finalize_Sync;
Finalize_Shared_Data;
exception when E : others =>
Finalize_Sync;
Finalize_Shared_Data;
Fatal_Exception (E, "A018: P9900x0");
end Parent_Main;
procedure Child_Main is
begin
Data := Shared_Data;
Initialize_Scheduling (Data);
Work (Jobs (Child));
exception when E : others => Fatal_Exception (E, "A019: P9900x0");
end Child_Main;
end P9900x0;
|