/* Allocate resources in request for process i, only if it
results in a safe state and return 1, else return 0 */
int resource_request(int i, int *request)
{
pthread_mutex_lock(&state_mutex);
int j;
for(j = 0; j < n; j++)
{
if(request[j] > s->need[i][j])
{
fprintf(stderr, "Request higher than Need for process %d!", i);
pthread_mutex_unlock(&state_mutex);
exit(0);
}
}
for(j = 0; j < n; j++)
{
if(request[j] > s->available[j])
{
pthread_mutex_unlock(&state_mutex);
return 0;
}
}
for(j = 0; j < n; j++)
{
s->available[j] = s->available[j] - request[j];
s->allocation[i][j] = s->allocation[i][j] + request[j];
s->need[i][j] = s->need[i][j] - request[j];
}
if(!safety_check())
{
for(j = 0; j < n; j++)
{
s->available[j] = s->available[j] + request[j];
s->allocation[i][j] = s->allocation[i][j] - request[j];
s->need[i][j] = s->need[i][j] + request[j];
}
pthread_mutex_unlock(&state_mutex);
return 0;
}
else
{
pthread_mutex_unlock(&state_mutex);
return 1;
}
}
void PAGE_ShowSafetyDialog()
{
if (dialog) {
u64 unsafe = safety_check();
if (! unsafe) {
DialogClose(dialog, 0);
safety_confirmed();
} else {
safety_string_cb(NULL, NULL);
u32 crc = Crc(tempstring, strlen(tempstring));
if (crc != dialogcrc) {
GUI_Redraw(dialog);
dialogcrc = crc;
}
}
} else {
tempstring[0] = 0;
dialogcrc = 0;
dialog = GUI_CreateDialog(&gui->dialog, DIALOG1_X, DIALOG1_Y,
DIALOG1_WIDTH, DIALOG1_HEIGHT, NULL, safety_string_cb, safety_ok_cb, dtOk, NULL);
}
}
int main(int argc, char* argv[])
{
/* Get size of current state as input */
int i, j;
printf("Number of processes: \n");
scanf("%d", &m);
printf("Number of resources: \n");
scanf("%d", &n);
/* Allocate memory for state */
s = malloc(sizeof(State));
s->resource = malloc(sizeof(int) * n);
s->available = malloc(sizeof(int) * n);
s->max = malloc(sizeof(int *) * m);
s->allocation = malloc(sizeof(int *) * m);
s->need = malloc(sizeof(int *) * m);
for(i = 0; i < m; i++)
{
s->max[i] = malloc(sizeof(int) * n);
s->allocation[i] = malloc(sizeof(int) * n);
s->need[i] = malloc(sizeof(int) * n);
}
/* Get current state as input */
printf("Resource vector: \n");
for(i = 0; i < n; i++)
scanf("%d", &s->resource[i]);
printf("Enter max matrix: \n");
for(i = 0;i < m; i++)
for(j = 0;j < n; j++)
scanf("%d", &s->max[i][j]);
printf("Enter allocation matrix:");
for(i = 0; i < m; i++)
for(j = 0; j < n; j++) {
scanf("%d", &s->allocation[i][j]);
}
printf("\n");
/* Calcuate the need matrix */
for(i = 0; i < m; i++)
for(j = 0; j < n; j++)
s->need[i][j] = s->max[i][j]-s->allocation[i][j];
/* Calcuate the availability vector */
for(j = 0; j < n; j++) {
int sum = 0;
for(i = 0; i < m; i++)
sum += s->allocation[i][j];
s->available[j] = s->resource[j] - sum;
}
/* Output need matrix and availability vector */
printf("Need matrix:\n");
for(i = 0; i < n; i++)
printf("R%d ", i+1);
printf("\n");
for(i = 0; i < m; i++) {
for(j = 0; j < n; j++)
printf("%d ",s->need[i][j]);
printf("\n");
}
printf("Availability vector:\n");
for(i = 0; i < n; i++)
printf("R%d ", i+1);
printf("\n");
for(j = 0; j < n; j++)
printf("%d ",s->available[j]);
printf("\n");
if(safety_check())
{
printf("State was safe. \n");
}
else
{
fprintf(stderr, "State was not safe.\n");
return 1;
}
/* Seed the random number generator */
struct timeval tv;
gettimeofday(&tv, NULL);
srand(tv.tv_usec);
/* Create m threads */
pthread_t *tid = malloc(m*sizeof(pthread_t));
for (i = 0; i < m; i++)
pthread_create(&tid[i], NULL, process_thread, (void *) (long) i);
/* Wait for threads to finish */
pthread_exit(0);
free(tid);
/* Free state memory */
for (i = 0; i < m; i++) {
free(s->max[i]);
free(s->allocation[i]);
free(s->need[i]);
}
free(s->resource);
free(s->available);
free(s->max);
free(s->allocation);
free(s->need);
free(s);
}
