// A small demo program for pthread_create and pthread_join

#include <pthread.h>
#include <iostream>

using namespace std;

extern "C" void* do_something(void* arg) {
   int number = *((int*) arg);
   cout << "Thread " << number << " does something." << endl;
   return arg;
} // do_something

int main() {
   const int THREADS = 10;
   pthread_t thread[THREADS];
   int args[THREADS];

   for (int i = 0; i < THREADS; ++i) {
      args[i] = i;
      if (pthread_create(&thread[i], 0, do_something, &args[i])) {
	 cerr << "pthread_create failed, aborting!\n" << endl;
	 exit(1);
      }
      cout << "Thread " << i << " started." << endl;
   }

   cout << "Now we are waiting for all to finish:" << endl;
   for (int i = 0; i < THREADS; ++i) {
      int* resultp;
      if (pthread_join(thread[i], (void**) &resultp)) {
	 cerr << "pthread_join failed, aborting!\n" << endl;
	 exit(1);
      }
      cout << "Thread " << i << " finished. Got "
	 << *resultp << " as return value." << endl;
   }
} // main