Vyznam dual core

[Fox!MURDER]

ok, to ifdef a ifndef som vsetko pokladal za ifndef

- problem je iny - citas zamknute data

ok. tak sec, opravim to ...

#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>
int a = 0;
int b = 0;
pthread_mutex_t mut_a = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t mut_b = PTHREAD_MUTEX_INITIALIZER;

void *f_thread1 ();
void *f_thread2 ();
int
main (void)
{
  pthread_t thread1, thread2;
  int iret1, iret2;

  iret1 = pthread_create (&thread1, NULL, f_thread1, NULL);
  iret2 = pthread_create (&thread2, NULL, f_thread2, NULL);
  pthread_join (thread1, NULL);
  pthread_join (thread2, NULL);

  printf ("a = %d\n", a);
  printf ("b = %d\n", b);
  exit (0);
}


void *
f_thread1 ()
{
  int x = 0;
  for (x = 0; x < 65535; x++)
    {
      int temp1, temp2;
      {
#ifdef WHOLELOCK
        pthread_mutex_lock (&mut_a);
        pthread_mutex_lock (&mut_b);
#endif
#ifndef WHOLELOCK
        pthread_mutex_lock (&mut_a);
#endif
        temp1 = a + 1;
#ifndef WHOLELOCK
        pthread_mutex_unlock (&mut_a);
        pthread_mutex_lock (&mut_b);
#endif
        temp2 = b + 1;
#ifndef WHOLELOCK
        pthread_mutex_unlock (&mut_b);
        pthread_mutex_lock (&mut_b);
#endif
        b = temp2;
#ifndef WHOLELOCK
        pthread_mutex_unlock (&mut_b);
        pthread_mutex_lock (&mut_a);
#endif
        a = temp1;
#ifndef WHOLELOCK
        pthread_mutex_unlock (&mut_a);
#endif
#ifdef WHOLELOCK
        pthread_mutex_unlock (&mut_a);
        pthread_mutex_unlock (&mut_b);
#endif
      }
    }
}
void *
f_thread2 ()
{
  int x = 0;
  for (x = 0; x < 65535; x++)
    {
      int temp1, temp2;
      {
#ifdef WHOLELOCK
          pthread_mutex_lock (&mut_a);
          pthread_mutex_lock (&mut_b);
#endif
#ifndef WHOLELOCK
          pthread_mutex_lock (&mut_a);
#endif
          temp1 = a - 1;
#ifndef WHOLELOCK
          pthread_mutex_unlock (&mut_a);
          pthread_mutex_lock (&mut_b);
#endif
          temp2 = b - 1;
#ifndef WHOLELOCK
          pthread_mutex_unlock (&mut_b);
          pthread_mutex_lock (&mut_b);
#endif
          b = temp2;
#ifndef WHOLELOCK
          pthread_mutex_unlock (&mut_b);
          pthread_mutex_lock (&mut_a);
#endif
          a = temp1;
#ifndef WHOLELOCK
          pthread_mutex_unlock (&mut_a);
#endif
#ifdef WHOLELOCK
          pthread_mutex_unlock (&mut_a);
          pthread_mutex_unlock (&mut_b);
#endif
        }
      }
    }

localhost ~ # gcc -pthread -o tt-nowholelock threadtest.c
localhost ~ # ./tt-nowholelock
a = 11691
b = -538

sice to neni presne to, co ma implementovany valve, protoze pri cteni zamykam jak pro cteni, tak pro zapis ... ale stejne ...