.
1. (N), , .
procedure INIT; common integer N;
Begin N: =1; start (P1); start (P2); end;
Process P1; common integer N;
Begin while true do begin BEFORE1; while N=2 do; CS1; N: =2; AFTER1; end; end;
Process P2; common integer N;
Begin while true do begin BEFORE2; while N=1 do; CS2; N: =1; AFTER2; end; end;
, : , , , , , , .. .
2. -, , , .
Procedure INIT; common Boolean C1, C2;
Begin C1:=false; C2:=false; start (P1); start (P2); end;
Process P1; common Boolean C1, C2;
Begin while true do begin BEFORE1; while C2 do; C1:=true; CS1; C1:=false; AFTER1; end; end;
Process P2; common Boolean C1, C2;
Begin while true do begin BEFORE2; while C1 do; C2:=true; CS2; C2:=false; AFTER2; end; end;
, . , - .
3.
, , . , .
Procedure INIT; common Boolean C1, C2; common integer N;
Begin C1:=false; C2:=false; N: =1; start (P1); start (P2); end;
Process P1; common Boolean C1, C2;
Begin while true do begin BEFORE1; C1:=true; while C2 do begin if N=2 then begin C1:=false; while N=2 do; C1:=true; end; end; CS1; C1:=false; N: =2; AFTER1; end; end;
Process P2; common Boolean C1, C2;
Begin while true do begin BEFORE2; C2:=true; while C1 do begin if N=1 then begin C2:=false; while N=1 do; C2:=true; end; end; CS2; C2:=false; N: =1; AFTER2; end; end;
- , .
P (d) - , .. , V (d) , .
.
(Binary Semaphore) - 2 : (0-, 1-).
(Integer Semaphore) - :
1) : . , S>0 (.. ). S=0 .
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2) : , .
-.
, n 1- . , , . , , 1 . . . 2 , , 1 .
INIT: Binary Semaphore B; Integer Semaphore E, F; F: =1; E: =N; B: =1; Start (W); Start(R); end;
Process W: begin while true do begin P(B); P(E); V(B); V(F) { }; end; ; end;
Process R: begin while true do begin P(F); P(B); Read(P) { , }; V(B); V(E) { }; end; ; end;
WinNT.
1. . . WaitForSingleObject - . , ( ) . WAIT_OBJECT_0 ; WAIT_TIMEOUT ; WAIT_ABANDONED ( Mutex).
2. . . - CreateEvent, , . . , OpenEvent. - SetEvent, ResetEvent PulseEvent. , () , WaitForSingleObject WaitForMultipleObject. CloseObject.
3. Mutex. , . -, . . WaitForSingleObject WaitForMultipleObjects.
4. . - : (). , , , - , , . , .
