Simtel MSDOS 1992 December/simtel1292_SIMTEL_1292_Walnut_Creek.iso/msdos/ada/bd3.arc/BD3.LST

File List | 1989-03-12 | 22KB | 541 lines

  1 package BANK is
  2 ------------------------------------------------------------------------
  3 --| BEGIN PROLOGUE
  4 --| DESCRIPTION            : BANK defines a bank, the TELLER objects
  5 --|                        : within it, and the procedure PRINT_REPORT
  6 --|                        : (which reports on the status of the BANK).
  7 --|                        :
  8 --|                        : BANK is an abstract state machine, defining
  9 --|                        : a BANK object which contains TELLER objects.
 10 --|                        :
 11 --| REQUIREMENTS SUPPORTED : Bank Demonstration Program to show
 12 --|                        : object-oriented design and tasking
 13 --|                        : with Ada
 14 --|                        :
 15 --| LIMITATIONS            : None
 16 --| AUTHOR(S)              : Richard Conn (RLC)
 17 --| CHANGE LOG             : 1/16/89  RLC  Initial Design and Code
 18 --| CHANGE LOG             : 2/25/89  RLC  Final Review Prior to Release
 19 --| REMARKS                : None
 20 --| PORTABILITY ISSUES     : None
 21 --| END PROLOGUE
 22 ------------------------------------------------------------------------
 23
 24     -- TRANSACTION requested of a TELLER
 25     type TRANSACTION  is (ADD_NEW_CUSTOMER,
 26                           GET_BALANCE,
 27                           MAKE_DEPOSIT,
 28                           MAKE_WITHDRAWAL);
 29
 30     -- Unit of currency
 31     type DOLLAR       is new FLOAT;
 32
 33     -- Identification of a CUSTOMER
 34     type CUSTOMER_ID  is new NATURAL range 1 .. NATURAL'LAST;
 35
 36     -- Index of and Number of TELLER objects within the bank
 37     type TELLER_INDEX is new NATURAL range 1 .. 4;
 38
 39     -- A TELLER_PERSON is an object to which a CUSTOMER may make a REQUEST
 40     -- The BANK tells the TELLER_PERSON to START_WORK, giving the
 41     -- TELLER_PERSON its TELLER_NUMBER
 42     task type TELLER_PERSON is
 43     entry REQUEST(ID     : in out CUSTOMER_ID;
 44               KIND   : in TRANSACTION;
 45               AMOUNT : in out DOLLAR);
 46     end TELLER_PERSON;
 47     -- These are the TELLER objects available at the bank
 48     TELLER : array(TELLER_INDEX) of TELLER_PERSON;
 49
 50     -- PRINT_REPORT gives the transaction log of all the bank
 51     -- customers
 52     procedure PRINT_REPORT;
 53
 54     -- STOP_WORK terminates all TELLER tasks
 55     procedure STOP_WORK;
 56 end BANK;
 57 --
 58 with CONSOLE;
 59 package body BANK is
 60 ------------------------------------------------------------------------
 61 --| BEGIN PROLOGUE
 62 --| DESCRIPTION            : Package Body BANK implements the TELLER
 63 --|                        : tasks and the PRINT_REPORT procedure.
 64 --|                        : CUSTOMER data is maintained within the
 65 --|                        : BANK as a linked list.
 66 --|                        :
 67 --| REQUIREMENTS SUPPORTED : Bank Demonstration Program to show
 68 --|                        : object-oriented design and tasking
 69 --|                        : with Ada
 70 --|                        :
 71 --| LIMITATIONS            : None
 72 --| AUTHOR(S)              : Richard Conn (RLC)
 73 --| CHANGE LOG             : 1/16/89  RLC  Initial Design and Code
 74 --| CHANGE LOG             : 2/25/89  RLC  Final Review Prior to Release
 75 --| REMARKS                : None
 76 --| PORTABILITY ISSUES     : Uses CONSOLE (TEXT_IO), so is very portable;
 77 --|                        : no known portability problems.
 78 --| END PROLOGUE
 79 ------------------------------------------------------------------------
 80
 81     -- Identifier of next customer
 82     NEXT_ID                  : CUSTOMER_ID           := CUSTOMER_ID'FIRST;
 83
 84     -- Linked list of customer data
 85     type CUSTOMER_DATA;
 86     type CUSTOMER_DATA_POINTER is access CUSTOMER_DATA;
 87     type CUSTOMER_DATA is record
 88     ID                  : CUSTOMER_ID;
 89     BALANCE             : DOLLAR                := 0.0;
 90     TRANSACTION_COUNT   : NATURAL               := 0;
 91     ATTEMPTED_OVERDRAWS : NATURAL               := 0;
 92     NEXT                : CUSTOMER_DATA_POINTER := null;
 93     end record;
 94
 95     -- Count of number of transactions for each TELLER object
 96     TELLER_TRANSACTION_COUNT : array(TELLER_INDEX) of NATURAL
 97       := (others => 0);
 98
 99     -- Pointers to first and last customer data entries
100     FIRST_CUSTOMER           : CUSTOMER_DATA_POINTER := null;
101     LAST_CUSTOMER            : CUSTOMER_DATA_POINTER := null;
102
103 --
104 -- package body BANK
105     -- Print a report of the status of the BANK
106     procedure PRINT_REPORT is
107     CURRENT_CUSTOMER : CUSTOMER_DATA_POINTER;
108     begin
109
110         -- Check for any customers and issue an error message if none
111     if NEXT_ID = CUSTOMER_ID'FIRST then
112         CONSOLE.WRITE("The bank doesn't have any customers");
113         CONSOLE.WRITE(CONSOLE.NEW_LINE);
114
115         -- Generate report
116     else
117
118             -- Customer balance, transaction count, attempted overdraw
119             -- count report
120         CONSOLE.WRITE("**** BANK STATUS REPORT ****");
121         CONSOLE.WRITE(CONSOLE.NEW_LINE);
122         CONSOLE.WRITE(
123               "Customer      Balance  Transactions  Attempted_Overdraws");
124         CONSOLE.WRITE(CONSOLE.NEW_LINE);
125         CURRENT_CUSTOMER := FIRST_CUSTOMER;
126         while CURRENT_CUSTOMER /= null loop
127         CONSOLE.WRITE(INTEGER(CURRENT_CUSTOMER.ID), 5);
128         CONSOLE.WRITE("     ");
129         CONSOLE.WRITE(FLOAT(CURRENT_CUSTOMER.BALANCE), 8, 2);
130         CONSOLE.WRITE("      ");
131         CONSOLE.WRITE(INTEGER(CURRENT_CUSTOMER.TRANSACTION_COUNT), 8);
132         CONSOLE.WRITE("             ");
133         CONSOLE.WRITE(INTEGER(CURRENT_CUSTOMER.ATTEMPTED_OVERDRAWS),
134           8);
135         CONSOLE.WRITE(CONSOLE.NEW_LINE);
136         CURRENT_CUSTOMER := CURRENT_CUSTOMER.NEXT;
137         end loop;
138         CONSOLE.WRITE(CONSOLE.NEW_LINE);
139
140             -- Teller transaction count report
141         CONSOLE.WRITE("Teller           : ");
142         for I in TELLER_INDEX loop
143         CONSOLE.WRITE(INTEGER(I), 8);
144         end loop;
145         CONSOLE.WRITE(CONSOLE.NEW_LINE);
146         CONSOLE.WRITE("Transaction_Count: ");
147         for I in TELLER_INDEX loop
148         CONSOLE.WRITE(INTEGER(TELLER_TRANSACTION_COUNT(I)), 8);
149         end loop;
150         CONSOLE.WRITE(CONSOLE.NEW_LINE);
151
152     end if;
153     end PRINT_REPORT;
154
155     -- Terminate all TELLER tasks
156     procedure STOP_WORK is
157     begin
158     for I in TELLER_INDEX loop
159         abort TELLER(I);
160     end loop;
161     end STOP_WORK;
162 --
163 -- package body BANK
164
165     -- FIND_CUSTOMER is used to find a CUSTOMER_DATA record
166     -- based on a CUSTOMER_ID number
167     function FIND_CUSTOMER(ID : in CUSTOMER_ID)
168                 return CUSTOMER_DATA_POINTER is
169     CURRENT_CUSTOMER : CUSTOMER_DATA_POINTER;
170     begin
171     CURRENT_CUSTOMER := FIRST_CUSTOMER;
172     while CURRENT_CUSTOMER /= null loop
173         exit when CURRENT_CUSTOMER.ID = ID;
174         CURRENT_CUSTOMER := CURRENT_CUSTOMER.NEXT;
175     end loop;
176     return CURRENT_CUSTOMER;
177     end FIND_CUSTOMER;
178
179
180 --
181 -- package body BANK
182
183     task TELLER_ASSIGNER is
184     -- This task assigns an ID number to a teller.
185     -- TELLER_ASSIGNER is called by the TELLER_PERSON task when the
186     -- TELLER_PERSON task first starts up.
187     entry GET_TELLER_ID(ID : out TELLER_INDEX);
188     end TELLER_ASSIGNER;
189
190     task body TELLER_ASSIGNER is
191     NEXT_TELLER_ID : TELLER_INDEX := TELLER_INDEX'FIRST;
192     begin
193     loop
194         accept GET_TELLER_ID(ID : out TELLER_INDEX) do
195         ID := NEXT_TELLER_ID;
196         if NEXT_TELLER_ID /= TELLER_INDEX'LAST then
197             NEXT_TELLER_ID := NEXT_TELLER_ID + 1;
198         end if;
199         end GET_TELLER_ID;
200     end loop;
201     end TELLER_ASSIGNER;
202
203 --
204 -- package body BANK
205
206     -- Implementation of a TELLER task
207     task body TELLER_PERSON is
208
209     THIS_CUSTOMER : CUSTOMER_DATA_POINTER;
210     MY_NUMBER     : TELLER_INDEX;
211
212     begin
213
214         -- TELLER gets his ID number
215     TELLER_ASSIGNER.GET_TELLER_ID(MY_NUMBER);
216
217         -- TELLER loops on REQUESTs from CUSTOMERs
218     loop
219         accept REQUEST(ID     : in out CUSTOMER_ID;
220                KIND   : in TRANSACTION;
221                AMOUNT : in out DOLLAR) do
222
223                 -- Increment teller's transaction count
224         TELLER_TRANSACTION_COUNT(MY_NUMBER)
225                     := TELLER_TRANSACTION_COUNT(MY_NUMBER) + 1;
226
227 --
228 -- package body BANK
229
230                 -- Process REQUEST
231         case KIND is
232
233             when ADD_NEW_CUSTOMER =>
234             if LAST_CUSTOMER = null then
235                 LAST_CUSTOMER := new CUSTOMER_DATA;
236                 FIRST_CUSTOMER := LAST_CUSTOMER;
237             else
238                 LAST_CUSTOMER.NEXT := new CUSTOMER_DATA;
239                 LAST_CUSTOMER := LAST_CUSTOMER.NEXT;
240             end if;
241             LAST_CUSTOMER.ID := NEXT_ID;
242             ID := NEXT_ID;
243             NEXT_ID := NEXT_ID + 1;
244             THIS_CUSTOMER := LAST_CUSTOMER;
245
246             when GET_BALANCE =>
247             THIS_CUSTOMER := FIND_CUSTOMER(ID);
248             AMOUNT := THIS_CUSTOMER.BALANCE;
249
250             when MAKE_DEPOSIT =>
251             THIS_CUSTOMER := FIND_CUSTOMER(ID);
252             THIS_CUSTOMER.BALANCE
253                             := THIS_CUSTOMER.BALANCE + AMOUNT;
254             AMOUNT := THIS_CUSTOMER.BALANCE;
255
256             when MAKE_WITHDRAWAL =>
257             THIS_CUSTOMER := FIND_CUSTOMER(ID);
258             if THIS_CUSTOMER.BALANCE < AMOUNT then
259                 AMOUNT := 0.0;
260                 THIS_CUSTOMER.ATTEMPTED_OVERDRAWS :=
261                   THIS_CUSTOMER.ATTEMPTED_OVERDRAWS + 1;
262             else
263                 THIS_CUSTOMER.BALANCE
264                                 := THIS_CUSTOMER.BALANCE - AMOUNT;
265             end if;
266
267         end case;
268
269                 -- Increment CUSTOMER's transaction count
270         THIS_CUSTOMER.TRANSACTION_COUNT
271                     := THIS_CUSTOMER.TRANSACTION_COUNT + 1;
272
273         end REQUEST;
274
275     end loop;
276
277     end TELLER_PERSON;
278
279 end BANK;
280
281 --
282 package CUSTOMER_WORLD is
283 ------------------------------------------------------------------------
284 --| BEGIN PROLOGUE
285 --| DESCRIPTION            : CUSTOMER_WORLD is an abstract state machine
286 --|                        : which defines the collection of all CUSTOMERs
287 --|                        : of the BANK.  It allows the mainline procedure
288 --|                        : to ADD a new CUSTOMER and TERMINATE_ALL
289 --|                        : current CUSTOMERs.  The CUSTOMER itself acts
290 --|                        : as an independent task and requires no
291 --|                        : direct interaction with the mainline once
292 --|                        : it starts.
293 --|                        :
294 --| REQUIREMENTS SUPPORTED : Bank Demonstration Program to show
295 --|                        : object-oriented design and tasking
296 --|                        : with Ada
297 --|                        :
298 --| LIMITATIONS            : None
299 --| AUTHOR(S)              : Richard Conn (RLC)
300 --| CHANGE LOG             : 1/16/89  RLC  Initial Design and Code
301 --| CHANGE LOG             : 2/25/89  RLC  Final Review Prior to Release
302 --| REMARKS                : None
303 --| PORTABILITY ISSUES     : None
304 --| END PROLOGUE
305 ------------------------------------------------------------------------
306
307     -- Add another CUSTOMER task to the system
308     procedure ADD;
309
310     -- Terminate all CUSTOMERs in the system
311     procedure TERMINATE_ALL;
312
313 end CUSTOMER_WORLD;
314
315 --
316 with BANK;
317 with RANDOM;
318 package body CUSTOMER_WORLD is
319
320     -- Support infix operations, like DOLLAR < DOLLAR
321     use  BANK;
322
323     -- This is the amount that a CUSTOMER initially deposits
324     -- into his account
325     INITIAL_DEPOSIT : constant BANK.DOLLAR          := 100.0;
326
327     -- A CUSTOMER is a task, running concurrently with the TELLERs,
328     -- other CUSTOMERs, and the mainline task
329     task type CUSTOMER;
330
331     -- CUSTOMER_POINTER is a pointer to a CUSTOMER, used to
332     -- create new customers and track old customers in the linked
333     -- list of customers used for task termination when the
334     -- program is complete
335     type CUSTOMER_POINTER              is access CUSTOMER;
336
337     -- These are the constructs used to create a linked list of
338     -- the customers
339     type CUSTOMER_LIST_ELEMENT;
340     type CUSTOMER_LIST_ELEMENT_POINTER is access CUSTOMER_LIST_ELEMENT;
341     type CUSTOMER_LIST_ELEMENT is record
342     THIS_CUSTOMER : CUSTOMER_POINTER;
343     NEXT          : CUSTOMER_LIST_ELEMENT_POINTER := null;
344     end record;
345
346     -- Pointer to the first of the customers
347     FIRST_CUSTOMER  : CUSTOMER_LIST_ELEMENT_POINTER := null;
348     LAST_CUSTOMER   : CUSTOMER_LIST_ELEMENT_POINTER := null;
349
350 --
351 -- package body CUSTOMER_WORLD
352
353     -- Implementation of the CUSTOMER task
354     task body CUSTOMER is
355
356     ID                 : BANK.CUSTOMER_ID   := BANK.CUSTOMER_ID'FIRST;
357     BALANCE            : BANK.DOLLAR        := 0.0;
358     AMOUNT             : BANK.DOLLAR        := 0.0;
359     MY_TRANSACTION     : BANK.TRANSACTION;
360
361         -- SELECT_TELLER makes a random selection of one of the
362         -- BANK's tellers
363     function SELECT_TELLER return BANK.TELLER_INDEX is
364     begin
365         return BANK.TELLER_INDEX(
366                 RANDOM.NUMBER * FLOAT(BANK.TELLER_INDEX'LAST) + 1.0);
367     exception
368         when others =>
369         return BANK.TELLER_INDEX'LAST;
370     end SELECT_TELLER;
371
372     begin    -- CUSTOMER activity
373
374         -- As a new CUSTOMER, the first two transactions of the
375         -- CUSTOMER are to ask the TELLER to add him as a new
376         -- CUSTOMER and make an initial deposit
377     BANK.TELLER(SELECT_TELLER).REQUEST(ID, BANK.ADD_NEW_CUSTOMER,
378       BALANCE);
379     BALANCE := INITIAL_DEPOSIT;
380     BANK.TELLER(SELECT_TELLER).REQUEST(ID, BANK.MAKE_DEPOSIT, BALANCE);
381
382         -- The rest of the life of the CUSTOMER is spent in the
383         -- these steps within the following loop:
384         --    (1) delay a random amount of time from 0 to 5 seconds
385         --    (2) compute a random amount from -$50 to +$50
386         --    (3) if the random amount is negative, attempt to
387         --        withdraw that amount; if positive, deposit that
388         --        amount
389     loop
390         delay DURATION(5.0 * RANDOM.NUMBER);
391         AMOUNT := BANK.DOLLAR(100.0 * RANDOM.NUMBER - 50.0);
392         if AMOUNT < DOLLAR'(0.0) then
393         MY_TRANSACTION := BANK.MAKE_WITHDRAWAL;
394         AMOUNT := -AMOUNT;
395         else
396         MY_TRANSACTION := BANK.MAKE_DEPOSIT;
397         end if;
398         BANK.TELLER(SELECT_TELLER).REQUEST(ID, MY_TRANSACTION, AMOUNT);
399     end loop;
400
401     end CUSTOMER;
402
403 --
404 -- package body CUSTOMER_WORLD
405
406     -- Add a new CUSTOMER to the linked list
407     procedure ADD is
408     begin
409
410         -- If the list is empty, start a new list
411     if LAST_CUSTOMER = null then
412         FIRST_CUSTOMER := new CUSTOMER_LIST_ELEMENT;
413         LAST_CUSTOMER := FIRST_CUSTOMER;
414
415         -- If the list is not empty, add an element onto it
416     else
417         LAST_CUSTOMER.NEXT := new CUSTOMER_LIST_ELEMENT;
418         LAST_CUSTOMER := LAST_CUSTOMER.NEXT;
419     end if;
420
421         -- Start a new CUSTOMER task
422     LAST_CUSTOMER.THIS_CUSTOMER := new CUSTOMER;
423
424     end ADD;
425
426     -- Terminate all CUSTOMER tasks by moving thru the linked list
427     -- and explicitly terminating the tasks pointed to by the list
428     -- elements.
429     procedure TERMINATE_ALL is
430     CURRENT_CUSTOMER : CUSTOMER_LIST_ELEMENT_POINTER;
431     begin
432     CURRENT_CUSTOMER := FIRST_CUSTOMER;
433     while CURRENT_CUSTOMER /= null loop
434         abort CURRENT_CUSTOMER.THIS_CUSTOMER.all;
435         CURRENT_CUSTOMER := CURRENT_CUSTOMER.NEXT;
436     end loop;
437     end TERMINATE_ALL;
438
439 end CUSTOMER_WORLD;
440
441 --
442 with BANK;
443 with CUSTOMER_WORLD;
444 with CONSOLE;
445 procedure BD3 is                           -- BANK_DEMO_3
446 ------------------------------------------------------------------------
447 --| BEGIN PROLOGUE
448 --| DESCRIPTION            : Procedure BD3 (BANK DEMO 3) is a mainline
449 --|                        : which demonstrates the operation of the
450 --|                        : BANK.  Upon invocation, the console becomes
451 --|                        : a command processor for the bank manager.
452 --|                        : The bank manager can obtain the status of
453 --|                        : the bank (balances, number of transactions,
454 --|                        : and attempted overdraws of all customers
455 --|                        : and number of transactions processed by all
456 --|                        : tellers) in a single or continuous (group
457 --|                        : of 11 over about one minute) display.
458 --|                        : The user at the console can also cause new
459 --|                        : Customer tasks to be created and shut down
460 --|                        : the system.
461 --|                        :
462 --| REQUIREMENTS SUPPORTED : Bank Demonstration Program to show
463 --|                        : object-oriented design and tasking
464 --|                        : with Ada
465 --|                        :
466 --| LIMITATIONS            : None
467 --| AUTHOR(S)              : Richard Conn (RLC)
468 --| CHANGE LOG             : 1/16/89  RLC  Initial Design and Code
469 --| CHANGE LOG             : 2/25/89  RLC  Final Review Prior to Release
470 --| REMARKS                : None
471 --| PORTABILITY ISSUES     : Uses CONSOLE (TEXT_IO), so is very portable;
472 --|                        : no known portability problems.
473 --| END PROLOGUE
474 ------------------------------------------------------------------------
475
476     -- Line input from the console
477     INPUT                               : CONSOLE.OUTSTRING;
478
479     -- Number of continuous status reports displayed by the 'c'
480     -- command before control is returned to the console
481     NUMBER_OF_CONTINUOUS_STATUS_REPORTS : constant := 10;
482
483 --
484 -- procedure BD3
485
486 begin                                      -- mainline
487
488     -- This is the beginning of the main loop.  In this loop,
489     -- a list of commands is printed on the console, the user
490     -- at the console (as CUSTOMER 0) enters one of these commands
491     -- followed by striking the RETURN key, and the command is
492     -- processed.
493     loop
494
495         -- Command listing and prompt
496     CONSOLE.WRITE("Enter");
497     CONSOLE.WRITE(CONSOLE.NEW_LINE);
498     CONSOLE.WRITE("  b for bank status");
499     CONSOLE.WRITE(CONSOLE.NEW_LINE);
500     CONSOLE.WRITE("  c for continuous bank status");
501     CONSOLE.WRITE(CONSOLE.NEW_LINE);
502     CONSOLE.WRITE("  s for start next customer");
503     CONSOLE.WRITE(CONSOLE.NEW_LINE);
504     CONSOLE.WRITE("  x for exit: ");
505     CONSOLE.READ(INPUT);
506
507         -- Interpretation and execution of input command
508     case INPUT(1) is
509         when 'b' | 'c' =>              -- Short or continuous bank status
510                                        -- report
511         BANK.PRINT_REPORT;
512         if INPUT(1) = 'c' then
513             for I in 1 .. NUMBER_OF_CONTINUOUS_STATUS_REPORTS loop
514             delay 5.0;
515             BANK.PRINT_REPORT;
516                     CONSOLE.WRITE(CONSOLE.NEW_LINE);
517             end loop;
518         end if;
519
520         when 's' =>                    -- Start up a new CUSTOMER
521         CUSTOMER_WORLD.ADD;
522
523         when 'x' =>                      -- Exit program
524         CUSTOMER_WORLD.TERMINATE_ALL;    -- Kill CUSTOMER tasks
525         BANK.STOP_WORK;                  -- Kill TELLER tasks
526         exit;                            -- Exit loop
527
528         when ' ' =>                    -- Non-error on a null input line
529         null;
530
531         when others =>                 -- Other commands are invalid
532         CONSOLE.WRITE("Invalid Command: ");
533         CONSOLE.WRITE(CONSOLE.TRIM(INPUT));
534         CONSOLE.WRITE(CONSOLE.NEW_LINE);
535
536     end case;
537
538     end loop;
539
540 end BD3;