#include

#include

#include

#include

#define NITER 1000000

int cnt = 0;

void * Count(void * a)

{

int i, tmp;

for(i = 0; i < NITER; i++)

{

tmp = cnt; /* copy the global cnt locally */

tmp = tmp+1; /* increment the local copy */

cnt = tmp; /* store the local value into the global cnt */

}

}

int main(int argc, char * argv[])

{

pthread_t tid1, tid2;

if(pthread_create(&tid1, NULL, Count, NULL))

{

printf(" ERROR creating thread 1");

exit(1);

}

if(pthread_create(&tid2, NULL, Count, NULL))

{

printf(" ERROR creating thread 2");

exit(1);

}

if(pthread_join(tid1, NULL)) /* wait for the thread 1 to finish */

{

printf(" ERROR joining thread");

exit(1);

}

if(pthread_join(tid2, NULL)) /* wait for the thread 2 to finish */

{

printf(" ERROR joining thread");

exit(1);

}

if (cnt < 2 * NITER)

printf(" BOOM! cnt is [%d], should be %d ", cnt, 2*NITER);

else

printf(" OK! cnt is [%d] ", cnt);

pthread_exit(NULL);

}