Bank.c

Bank.c

#include <string.h>
#include "bank.h"
#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
static int current_balance;


int BalanceFlag = 0; /* 0 for No Activity, 1 for Activity in the last 10 seconds */
pthread_mutex_t BalanceLock, FlagLock;


void *ActivityCheck (void *param)
{
	while(1)
	{
		/* Count to 10 seconds */
		sleep(10);
		/* If an activity has occured, Reset the Flag */
		/* Lock the Flag modification */
		while(pthread_mutex_init(&FlagLock, NULL) != 0);
		if(BalanceFlag == 1)
		{
		 // printf("prompt> ");
		 BalanceFlag = 0;
		 pthread_mutex_destroy(&FlagLock); 
		 continue;
		}

		/* Try locking, its okay to fail */
		pthread_mutex_init(&FlagLock, NULL);
		/* Destroy the lock */
		pthread_mutex_destroy(&FlagLock);
		/* If an activity hasn't occured */

		bank_do_command("withdraw", 2);
		printf("$2 fined \n");
		
		printf("prompt> ");
		fflush(stdout);
		/* Withdraw will Set Flag, which we don't want */
		BalanceFlag = 0;

	}
	
	return NULL;
}


int bank_init(int initial_balance)
{
	int err;
	if (initial_balance < 0) return 0;
	current_balance = initial_balance;

	/* Launch Thread for Activity Check here */
	pthread_t athread;
	err = pthread_create(&athread,NULL, ActivityCheck,NULL);
	if(err != 0) printf("Error Creating Thread\n");
	return 1;
}

//performs a command on the bank account.
//for recognized commands, the function 
//    returns the current balance, whether or not the requested
//    command was performed.
//returns -1 if the command wasn't recognized.
int bank_do_command(char *command, int value)
{


	/* Don't know if we should have a mutex lock here */
	if (strcmp(command, "balance") == 0) return current_balance;

	if (strcmp(command, "deposit") == 0)
	{
		if (value < 0) return -1; //generic error return
		
		/* Obtain Lock to change balance */
		while(pthread_mutex_init(&BalanceLock, NULL) != 0);
		
		while(pthread_mutex_init(&FlagLock, NULL) != 0);
		BalanceFlag = 1;
		pthread_mutex_destroy(&FlagLock);
		current_balance += value;
		
		pthread_mutex_destroy(&BalanceLock);
		
		return current_balance;
	}
	if (strcmp(command, "withdraw") == 0)
	{
		if (value < 0 || current_balance < value) return current_balance; 
		

		/* Obtain Lock to change balance */
		while(pthread_mutex_init(&BalanceLock, NULL) != 0);

		while(pthread_mutex_init(&FlagLock, NULL) != 0);
		BalanceFlag = 1;
		pthread_mutex_destroy(&FlagLock);

		current_balance -= value;
		
		pthread_mutex_destroy(&BalanceLock);

		return current_balance;
	}

	//I don't recognize this command
	return -1;
}

/* How to free things before exec */