//This model is an adaptation by Frits Vaandrager of
//a model made by Martijn Hendriks
// Number of processes in system:
const int N = 4;
// Number of semaphores:
const int M = 1;
// Names of the semaphores, ranging from 0 to M-1:
const int s = 0;
// The channels to synchronize with the semafores
// A call semWait(s) by process p translates to a sequence of two transitions labeled with
// semWait(s)(p)!
// semGo(s)(p)?
//A call semSignal(s) by process p translates to a transition labeled with
// semSignal(s)(p)!
chan semWait[M][N], semGo[M][N], semSignal[M][N];
Semaphoreconst int id, const int queue_size, const int init_val//The value of the semaphore
bool value = init_val;
//The queue of the semaphore
// -1 denotes an empty array entry
int[-1,N-1] queue[queue_size];
//An auxiliary variable used to temporarily store process id
meta int[0,N-1] q;
void initialize ()
{
for (i : int[0,queue_size-1])
{queue[i] = -1;}
}
void deQueue ()
{
for (i : int[1,queue_size-1])
queue[i-1] = queue[i];
queue[queue_size-1] = -1;
}
void enQueue (int p)
{
int i = 0;
while (queue[i]>=0){i++;};
queue[i]=p;
}
int[0,N-1] headQueue ( )
{
return queue[0];
}
bool fullQueue ( )
{
for (i : int[0,queue_size-1])
{
if (queue[i]==-1) {return false;}
}
return true;
}
bool emptyQueue ( )
{
return (queue[0]==-1);
}overflowProcessconst int pidcsP0 = Process(0);
P1 = Process(1);
P2 = Process(2);
P3 = Process(3);
Sem = Semaphore(s,N-1,1);
system
P0,
P1,
P2,
P3,
Sem;