Operating Systems - David Vernon

Processes
#include “prototypes.h”
#define FALSE 0
#define TRUE 1
#define N 2 /* number of processes */
int turn; /* global variable: who’s turn is it */
int interested[N]; /* all values initally 0 (FALSE) */
void enter_region(int process) /* process: who is entering (0 or 1) */
{
int other; /* id number of the other process */
}
other = 1 - process; /* set it to the other (of 2) processes *
interested[process] = TRUE; /* record interest in entering region *
turn = process; /* set flag *
while (turn == process && interested[other] == TRUE) ; /* wait */
void leave_region(int process) /* process: who is leaving (0 or 1) */
{
interested[process] = FALSE;/* indicate departure */
} Copyright © 2007 /* David from Vernon (www.vernon.eu) critical region */