// run a function in parallel N times, wait for the first one to finish
//
// run time is minimum of the run times for each function call
//
// main() uses an excessive amount of CPU time
//
#include <pthread.h>
#include <sched.h> // for sched_yield

#include "common.c"

 // start the threads
 //
  pthread_t t[N];

  for( int i = 0; i < N; ++i)
    if( pthread_create( &t[i], 0, f, &D[i].i ) ) { perror( "pthread_create"); return 1; }

 // wait until any one thread is finished
 //
  while(1)
  {
    int done = 0; for( int i = 0; i < N; ++i) if( D[i].size == 0) ++done;

    if( done > 0) break; // at least one thread is done

    sched_yield(); // wait a while
  }

 // stop all threads
 //
  for( int i = 0; i < N; ++i) pthread_cancel( t[i]);
}