MultithreadingAndCriticalsections/fr: what changed

Revision 1 to 2. Removed lines have a minus sign; added lines have a plus sign.

Old	New		Line
1	1		## Démonstration de programmation de Thread
2	2
3	3		``` pascal
4	4		{$mode objfpc}{$H+}
5	5		program Project1;
6	6
7	7		uses
8	8		{$ifdef unix}cthreads,
9	9		{$endif}Classes,
10	10		SysUtils;
11	11
12	12		var
13	13		CriticalSection: TRTLCriticalSection;
14	14		Counter: integer;
15	15		UseCriticalSection: boolean;
16	16
17	17		function Supposedly: string;
18	18		begin
19	19		if UseCriticalSection then
20	20		Result:=''
21	21		else Result:='supposedly ';
22	22		end;
23	23
24	24		type
25	25		{ TMyThread }
26	26
27	27		TMyThread = class(TThread)
28	28		private
29	29		FAFinished: boolean;
30	30		FID: integer;
31	31		public
32	32		constructor Create(CreateSuspended: Boolean; ID: integer; const StackSize: SizeUInt=DefaultStackSize);
33	33		procedure Execute; override;
34	34		property AFinished: boolean read FAFinished write FAFinished;
35	35		end;
36	36
37	37		constructor TMyThread.Create(CreateSuspended: Boolean; ID: integer; const StackSize: SizeUInt);
38	38		begin
39	39		inherited Create(CreateSuspended, StackSize);
40	40		FID:=ID;
41	41		end;
42	42
43	43		procedure TMyThread.Execute;
44	44		var
45	45		j: integer;
46	46		begin
47	47		FAFinished := False;
48	48		if UseCriticalSection then
49	49		EnterCriticalSection(CriticalSection);
50	50		try
51	51		for j := 1 to 1000000 do
52	52		Inc(Counter);
53	53		WriteLn(Format('Thread %d has %sfinished making 1000000 increments to Counter',[FID, Supposedly]));
54	54		finally
55	55		if UseCriticalSection then
56	56		LeaveCriticalSection(CriticalSection);
57	57		end;
58	58		FAFinished := True;
59	59		end;
60	60
61	61		function HasCriticalSection: string;
62	62		begin
63	63		if UseCriticalSection then
64	64		Result:=''
65	65		else Result:='NOT ';
66	66		end;
67	67
68	68		procedure ExerciseThreads(aUseCriticalSection: boolean);
69	69		var
70	70		Threads: array[1..20] of TMyThread;
71	71		AllFinished: boolean;
72	72		i: integer;
73	73		begin
74	74		Counter := 0;
75	75		UseCriticalSection:=aUseCriticalSection;
76	76		WriteLn(Format('A critical section is %sbeing used; Counter starts at %d',[HasCriticalSection, Counter]));
77	77		// start 20 threads
78	78		for i := Low(Threads) to High(Threads) do
79	79		Threads[i] := TMyThread.Create(False, i);
80	80		// wait till all threads finished
81	81		repeat
82	82		AllFinished := True;
83	83		for i := Low(Threads) to High(Threads) do
84	84		if not Threads[i].AFinished then
85	85		AllFinished := False;
86	86		until AllFinished;
87	87		// free the threads
88	88		for i := Low(Threads) to High(Threads) do
89	89		Threads[i].Free;
90	90		WriteLn('Final value of Counter=' + IntToStr(Counter));
91	91		WriteLn;
92	92		end;
93	93
94	94		var
95	95		b: boolean;
96	96		begin
97	97		// create the CriticalSection
98	98		InitCriticalSection(CriticalSection);
99	99		for b in Boolean do
100	100		ExerciseThreads(b);
101	101		// free the CriticalSection
102	102		DoneCriticalSection(CriticalSection);
103	103
104	104		{$IfDef WINDOWS}
105	105		Write(' Press [Enter] to finish');
106	106		ReadLn;
107	107		{$EndIf}
108	108		end.
109	109		```
110	110
111		-	\
112		-
113	111		---
114	112		From the Free Pascal wiki, page "MultithreadingAndCriticalsections/fr", as it stood on 2020-02-20 after a change by Trev, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).

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