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

void* servant( void* );

#define FALSE 0
#define TRUE  1

#define MAX 30

static int count;
static int list1[MAX];
static int list2[MAX];

/******************************************************************************
  Function main

  Initialize variables and create two additional threads, then wait for the
  servant threads to complete.
******************************************************************************/

int main()
{
  pthread_t mythread[2];
  int i;

  pthread_setconcurrency( 3 );

  count = 0;
  for (i=0; i<MAX; i++)
  {
    list1[i] = 0;
    list2[i] = 0;
  }

  for (i=0; i<2; i++)
  {
    if (pthread_create( &mythread[i], NULL, servant, (void*) i ))
    {
      printf( "*** Error creating thread ***\n" );
      exit( -1 );
    }
  }

  for (i=0; i<2; i++)
  {
    if (pthread_join ( mythread[i], NULL ))
    {
      printf( "*** Error joining thread ***\n" );
      exit( -2 );
    }
  }

  printf( "\nFinal contents of arrays:\n\n" );
  for (i=0; i<MAX; i++)
  {
    printf( "  %2d:  %d  %d", i, list1[i], list2[i] );

    if (list1[i] == 0 || list2[i] ==0 || list1[i] != list2[i])
    {
      printf( " *** error ***" );
    }
    printf( "\n" );
  }
  printf( "\nFinal value of count: %d\n\n", count );

  return 0;
}

/******************************************************************************
  Function servant

  Each servant thread loops MAX times, incrementing the count by 1
  and placing its thread ID into two parallel arrays.
******************************************************************************/

void* servant( void* arg )
{
  pthread_t tid = pthread_self();
   int i;
  for (i=0; i<MAX; i++)
  {
    if (count < MAX)
    {
      list1[count] = tid;

      if ((random()&0x00000003) == 0x00000003) thr_yield();

      list2[count] = tid;

      count = count + 1;
    }
  }

  return NULL;
}