Ex no: 7
Date:
BANKERS ALGORITHM FOR DEADLOCK
AVOIDANCE.
AIM:
To write a C program to implement banker's algorithm for deadlock avoidance
ALGORITHM:
Step-1: Start the program.
Step-2: Declare the memory for the process.
Step-3: Read the number of process, resources, allocation matrix and available matrix.
Step-4: Compare each and every process using the banker's algorithm.
Step-5: If the process is in safe state then it is a not a deadlock process otherwise it is a
deadlock process.
Step-6: produce the result of state of process.
Step-7: Stop the program.
PROGRAM:
#include <stdio.h>
#include <conio.h>
int max[100][100];
int alloc[100][100];
int need[100][100];
int avail[100];
int n, r;
void input();
void show();
void cal();
int main() {
printf("********** Banker's Algorithm **********\n");
input();
show();
cal();
getch();
return 0;
}
void input() {
int i, j;
printf("Enter the number of Processes: ");
scanf("%d", &n);
printf("Enter the number of resource instances: ");
scanf("%d", &r);
printf("Enter the Max Matrix\n");
for (i = 0; i< n; i++) {
for (j = 0; j < r; j++) {
scanf("%d", &max[i][j]);
}
}
printf("Enter the Allocation Matrix\n");
for (i = 0; i< n; i++) {
for (j = 0; j < r; j++) {
scanf("%d", &alloc[i][j]);
}
}
printf("Enter the Available Resources\n");
for (j = 0; j < r; j++) {
scanf("%d", &avail[j]);
}
}
void show() {
int i, j;
printf("Process\tAllocation\tMax\tAvailable\n");
for (i = 0; i< n; i++) {
printf("P%d\t", i + 1);
for (j = 0; j < r; j++) {
printf("%d ", alloc[i][j]);
}
printf("\t");
for (j = 0; j < r; j++) {
printf("%d ", max[i][j]);
}
printf("\t");
if (i == 0) {
for (j = 0; j < r; j++) {
printf("%d ", avail[j]);
}
}
printf("\n");
}
}
void cal() {
int finish[100], temp, flag = 1, k, c1 = 0;
int safe[100];
int i, j;
for (i = 0; i< n; i++) {
finish[i] = 0;
}
// Find need matrix
for (i = 0; i< n; i++) {
for (j = 0; j < r; j++) {
need[i][j] = max[i][j] - alloc[i][j];
}
}
printf("\n");
while (flag) {
flag = 0;
for (i = 0; i< n; i++) {
int c = 0;
for (j = 0; j < r; j++) {
if ((finish[i] == 0) && (need[i][j] <= avail[j])) {
c++;
}
}
if (c == r) {
for (k = 0; k < r; k++) {
avail[k] += alloc[i][j];
}
finish[i] = 1;
flag = 1;
printf("P%d->", i);
}
}
}
for (i = 0; i< n; i++) {
if (finish[i] == 1) {
c1++;
} else {
printf("P%d->", i);
}
}
if (c1 == n) {
printf("\nThe system is in a safe state\n");
} else {
printf("\nProcesses are in a deadlock\n");
printf("System is in an unsafe state\n");
}
}
RESULT:
Thus the C Program for implementation of banker's algorithm for deadlock avoidance
has been written and Executed Successfully.
Ex no: 8
Date:
ALGORITHMFORDEADLOCKDETECTION
AIM:
To write a C program to implement algorithm for deadlock detection
ALGORITHM:
Step-1: Start the program.
Step-2: Declare the memory for the process.
Step-3: Read the number of process, resources, allocation matrix and available matrix.
Step-4: Compare each and every process using the banker's algorithm.
Step-5: If the process is in safe state then it is a not a deadlock process otherwise it is a
deadlock process.
Step-6: produce the result of state of process.
Step-7: Stop the program.
PROGRAM:
#include <stdio.h>
#include <conio.h>
int max[100][100];
int alloc[100][100];
int need[100][100];
int avail[100];
int n, r;
void input();
void show();
void cal();
int main() {
printf("****** Deadlock Detection Algorithm ******\n");
input();
show();
cal();
getch();
return 0;
}
void input() {
int i, j;
printf("Enter the number of Processes: ");
scanf("%d", &n);
printf("Enter the number of resource instances: ");
scanf("%d", &r);
printf("Enter the Max Matrix:\n");
for (i = 0; i< n; i++) {
for (j = 0; j < r; j++) {
scanf("%d", &max[i][j]);
}
}
printf("Enter the Allocation Matrix:\n");
for (i = 0; i< n; i++) {
for (j = 0; j < r; j++) {
scanf("%d", &alloc[i][j]);
}
}
printf("Enter the Available Resources:\n");
for (j = 0; j < r; j++) {
scanf("%d", &avail[j]);
}
}
void show() {
int i, j;
printf("Process\tAllocation\tMax\tAvailable\n");
for (i = 0; i< n; i++) {
printf("\nP%d\t", i + 1);
for (j = 0; j < r; j++) {
printf("%d ", alloc[i][j]);
}
printf("\t");
for (j = 0; j < r; j++) {
printf("%d ", max[i][j]);
}
printf("\t");
if (i == 0) {
for (j = 0; j < r; j++) {
printf("%d ", avail[j]);
}
}
}
}
void cal() {
int finish[100], flag = 1, k, c1 = 0;
int dead[100];
int i, j;
for (i = 0; i< n; i++) {
finish[i] = 0;
// Find need matrix
for (j = 0; j < r; j++) {
need[i][j] = max[i][j] - alloc[i][j];
}
}
while (flag) {
flag = 0;
for (i = 0; i< n; i++) {
int c = 0;
for (j = 0; j < r; j++) {
if ((finish[i] == 0) && (need[i][j] <= avail[j])) {
c++;
}
}
if (c == r) {
for (k = 0; k < r; k++) {
avail[k] += alloc[i][k];
}
finish[i] = 1;
flag = 1;
}
}
}
int flag_deadlock = 0;
for (i = 0; i< n; i++) {
if (finish[i] == 0) {
dead[flag_deadlock] = i;
flag_deadlock++;
flag = 1;
}
}
if (flag == 1) {
printf("\n\nSystem is in Deadlock and the Deadlocked processes are:\n");
for (i = 0; i<flag_deadlock; i++) {
printf("P%d ", dead[i] + 1);
}
printf("\n");
} else {
printf("\nNo Deadlock Detected.\n");
}
}
RESULT:
Thus the C Program for implementation of algorithm for deadlock detection has been
written and Executed Successfully.
Ex no: 9
THREADING&SYNCHONIZATIONAPPLICATIONS
Date:
AIM:
To write a c program to implement Threading and Synchronization Applications
ALGORITHM:
Step 1: Start the process.
Step 2: Declare process thread, thread-id.
Step 3: Read the process thread and thread state.
Step 4: Check the process thread equals to thread-id by using if condition.
Step 5: Check the error state of the thread.
Step 6: Display the completed thread process.
Step 7: Stop the program.
PROGRAM:
#include<stdio.h>
#include<string.h>
#include<pthread.h>
#include<stdlib.h>
#include<unistd.h>
pthread_ttid[2];
void* doSomeThing(void *arg)
{
unsigned long i = 0;
pthread_t id = pthread_self();
if(pthread_equal(id,tid[0]))
{
printf("\n First thread processing\n");
}
else
{
printf("\n Second thread processing\n");
}
for(i=0; i<(0xFFFFFFFF);i++);
return NULL;
}
int main(void)
{
int i = 0;
int err;
while(i< 2)
{
err = pthread_create(&(tid[i]), NULL, &doSomeThing, NULL);
if (err != 0)
printf("\ncan't create thread :[%s]", strerror(err));
else
printf("\n Thread created successfully\n");
i++;
}
sleep(5);
return 0;
}
RESULT:
Thus the C Program for implementation of Threading and Synchronization Applications
has been written and Executed Successfully.
