Question

Using C programming please

5. Write a multithreaded program to do the following: Accepts two positive integers from the command line as the amounts to withdraw a. and deposit from an account. b. Creates two threads to perform withdraw and deposit operations repectively. Passes the amount to withdraw/deposit as the parameter to thread's runner function c. Waits for both threads to terminate. Since both threads need to update the account balance, it is necessary to protect sections. You may use mutex variable or semaphore for thread synchronization. You may assume that the initial account balance is $1000. // declare global variables here main function must initialize the global variables, mutex variable/semaphore, create threads and wait for them to terminate / the amounts to withdraw and deposit are command line int main (int arge, char *"argv)

Answer 1

Here is the exact program as specified. Please comment for any clarification. Thanks

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>

// Let us create a global variable to change it in threads
int accountBalance;
// thread array
pthread_t tid[2];

//mutex for mutual exclusion
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

// The function to be executed by all threads
void
addBalance (void *vargp)
{
// Store the value argument passed to this thread
int *myid = (int *) vargp;
//locking mutex function
pthread_mutex_lock (&mutex);
accountBalance += *myid;
//unlock thread
pthread_mutex_unlock (&mutex);
// Print the argument, static and global variables
printf ("Account Balance deposit: %d\n", accountBalance);
}

// The function to be executed by all threads
void
withdrawBalance (void *vargp)
{
// Store the value argument passed to this thread
int *myid = (int *) vargp;
//locking mutex function
pthread_mutex_lock (&mutex);
accountBalance -= *myid;
//unlock thread
pthread_mutex_unlock (&mutex);
// Print the global variables
printf ("Account Balance withdraw: %d\n", accountBalance);
}

int
main (int argc, char *argv[])
{
//initialise global variable
accountBalance = 10000;
  
//converting command line argument to integer values.
//first argument for withdraw
int withdraw=atoi(argv[1]);
  
//second argument for withdraw
int deposit=atoi(argv[2]);
  
//creating thread for withdrawBalance
pthread_create (&(tid[1]), NULL, withdrawBalance, (void *) &withdraw);
  
//creating thread for deposit balance
pthread_create (&(tid[0]), NULL, addBalance, (void *) &deposit);
  
//wait for thread to finish
pthread_join (tid[0], NULL);
  
//wait for thread to finish
pthread_join (tid[1], NULL);
pthread_exit (NULL);
return 0;
}

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