/* File:  ~liux/public_html/courses/cop4610/examples/simple-pthread.cc
   Purpose: Demonstrate how to create multiple threads in UNIX
            for COP4610
   Author:  Xiuwen Liu
   On the web: 
     http://www.cs.fsu.edu/~liux/courses/cop4610/examples/simple-pthread.cc
   Command to complie (Pay attention to -lpthread):
         g++ -o simple-pthread simple-pthread.cc -lpthread
*/

#include <sys/types.h>
#include <strings.h>
#include <sys/wait.h>
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
//#include <thread.h>
#include <stdlib.h>
#include <iostream.h>
#include <pthread.h>

int NUM_THREADS;
pthread_t *tid;      /* array of thread IDs */
int      *performed_transactions; 
int totalTransaction;
int *accounts;  /* Account balances */

void * RandomTransaction(void *msg);
int PerformATransaction(int from, int to, int val);
int CheckRunning(void);
typedef struct {
  int acct;
} PARA_INFO;

int mutex_lock_flag;
int main(int argc, char *argv[])
{
  pthread_attr_t  attr;
  PARA_INFO       *info;
  int i, sum;
  int c;
  extern char *optarg;
  extern int optind;
  unsigned int seed;
  mutex_lock_flag = 0;
  seed = 100;
  NUM_THREADS = 5;
  while ((c = getopt(argc, argv, "ms:t:")) != EOF) {
    switch(c) {
    case 'm':
      mutex_lock_flag = 1;
      break;
    case 's':
      seed = atoi(optarg);
      break;
    case 't':
      NUM_THREADS= atoi(optarg);
      break;
    default:
      printf("%c is not valid option.\n");
    }
  }
  
  printf("Initializing with seed %d\n", seed);
  srandom(seed);
  printf("Total number of threads is %d\n", NUM_THREADS);
  tid = (pthread_t *)malloc(sizeof(pthread_t) * NUM_THREADS);
  performed_transactions = (int *)malloc(sizeof(int)*NUM_THREADS);
  accounts = (int *)malloc(sizeof(int)*NUM_THREADS);
  info = (PARA_INFO *)malloc(sizeof(PARA_INFO)*NUM_THREADS);
  
  totalTransaction = 0;
  for (i=0; i < NUM_THREADS; i++) {
    accounts[i] = 1000;
    performed_transactions[i] = 0;
  }
  sum =0;
  for (i=0; i< NUM_THREADS; i++) {
    cout << "\n\tInit account "
	 << i+1 << "'s balance: " << accounts[i];
    sum += accounts[i];
  }
  cout <<"\n\tTotal initial balance is " << sum << endl;
  pthread_attr_init(&attr);
  
  for (i=0; i < NUM_THREADS; i++) {
    
    info[i].acct = i;
    
    if (pthread_create(&(tid[i]), &attr,
		        RandomTransaction, (void *)(&(info[i]))) <0) {
      perror("create thread: ");
      return -1;
    }
  }

  pthread_attr_destroy(&attr);
  
  for (i=0; i < NUM_THREADS; i++) {
    pthread_join((pthread_t)tid[i], 
		  (void **)NULL);
  }
  
  for (i=0; i < NUM_THREADS; i++) {
    cout << "\nAccount " << i+1 << " performed " 
	 << performed_transactions[i];
  }
  cout << "\n";
  return 0;
}

void * RandomTransaction(void *msg)
{
  pthread_t current_thr;
  int myAcct, toAcct;
  int amount;
  PARA_INFO *info;
  
  
  info = (PARA_INFO *)msg;
  
  current_thr = pthread_self();

  myAcct = info->acct;
  
  if (myAcct >= NUM_THREADS) {
    cerr << "Something must be wrong with the thread IDs.\n";
    return (void *)NULL;
  }
  cout << "Thread " << pthread_self() << " with account "
       << myAcct << " is running.\n";

  do {
    /* First figure out my account number */
    do {
      toAcct = ((int)random())%NUM_THREADS;
    } while (myAcct == toAcct);
    amount = (int)(random()%10+10);
    PerformATransaction(myAcct, toAcct, amount);
  } while(CheckRunning());
  return (void *)NULL;
}

int PerformATransaction(int from, int to, int val)
{
  int i, sum;
  
  if (accounts[from] < val) {
    //pthread_yield();
    if (random()&0x01)
      sleep(1);
    return -1;
  }
  
  performed_transactions[from]++;
  
  totalTransaction++;
  if ((totalTransaction %1) == 0) {

    sum =0;
    cout << "\n from (" << pthread_self() << ") Now " 
	 << totalTransaction 
	 << " transactions have been completed.";
    for (i=0; i < NUM_THREADS; i++) {
      cout << "\n\tAccount " << i+1 
	<< "'s balance: " << accounts[i];
      sum += accounts[i];
    }
    cout << "\n\tTotal balance after " 
	 << totalTransaction
	 << " transactions is " << sum << endl;
    
  }
  
 
  accounts[from] -= val;
  //  pthread_yield();
  if (random()%2==0)
    sleep(1);
  accounts[to] += val;
  return 0;
}


int CheckRunning(void)
{
  int i;
  i = (int)(totalTransaction < 10);
  return i;
}