Dijkstra posed each of the following solutions as a potential software solution to the critical section problem and then explained why they failed [Dijkstra, 1968]. Provide your explanation about why they failed. a. proc (int i) {
while (TRUE ) {
compute;
while (turn ! = i);
critical_section ;
turn = (i+1) mod 2;
}
shared int turn;
turn = 1;
fork ( proc, 1, 0);
fork (proc, 1, 1); 8.6
b. proc (int i) {
while (TRUE)
compute;
while (flagt ( i+1 ) mod 21);
flag [i]
critical_section; TRUE;
flag[i] FALSE;
}
}
shared boolean flag[2];
flag[1] = FALSE; flag[0]
fork ( proc , 1, 0);
fork (proc, 1, 1);
c. proc (int i) {
while (TRUE ) {
compute;
flag [i] = TRUE ;
while (flagl (i+1) mod 2] );
critical_section;
flag [i] = TRUE; FALSE;
}
}
shared boolean flag[2];
flag[0] flag [ 1 ] = FALSE;
fork (proc, 1, 0);
fork ( proc, 1, 1);