This article is pretty terrifying:

      #import <pthread.h>
      #import <stdlib.h>
      
      // Globals
      pthread_mutex_t *gLck;
      int gSum;

      int main (int argc, const char * argv[])
      {
          pthread_t *tFoo, *tBar;
          int tErr, tArgF, tArgB;
      
          // create the mutex construct
          tErr = pthread_mutex_init(gLck);