// based on a program written by Dr. Art DuPre
#include <iostream.h>
#include <pthread.h>
#include <stdlib.h>

void *task(void *arg) {
  for (int i=0;i<1000;i++) { 
    cout << (char *)arg;
    if(i%50==5)cout<<'\n';
    cout.flush();
  }
  return NULL;
}

int main() {
  pthread_t t1;
  if ( pthread_create(&t1, NULL, task, (void *)"1") != 0 ) {

    // pthread_create takes 4 arguments, 1st is a pointer to a 
    // pthread_t, the second is a pointer to thread attributes
    // (we pass in NULL to use default attributes.  third slot is
    // for a (pointer to a) function.  This function has to have 
    // return type void* and also a single argument of type void*.
    // The 4th (& last) argument is the arguement to be passed into
    // the function (task in this case).  This should be a pointer,
    // and we can cast this pointer to type void *.
 
    cout << "pthread_create() error" << endl;
    abort();
  }
  //  for (long j=0; j<100; ++j)
  //    for (long i=0; i<1000000; ++i);
  task((void *)"2");
  pthread_join(t1,NULL);

  // if the main program thread is allowed to exit, then all child
  // threads are destroyed & may not actually do their work.  So
  // use pthread_join to wait for the thread.
}