test.cc

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <sys/time.h>

int x = 0;
int *p;
int *q;
pthread_t new_thread;
pthread_mutex_t l;
pthread_cond_t cond;
struct timespec wait_time; // ANDREW: prevent deadlock
struct timeval now;

void *thread_start(void*) {
    pthread_mutex_lock(&l);
        *q = 0;
        if(x == 0)
           *p = 0;
    pthread_mutex_unlock(&l);
    usleep(100);
    pthread_cond_signal(&cond);
    return 0;
}

void deallocate(void *z) {
    free(z);
}

int main() {
    p = (int*)malloc(sizeof(int));
    q = (int*)malloc(sizeof(int));
    pthread_mutex_init(&l, NULL);
    pthread_cond_init(&cond, NULL);

    gettimeofday(&now, NULL);
    wait_time.tv_sec = now.tv_sec + 5;

    printf("pointer p: %p %p\n", &p, p);
    printf("pointer q: %p %p\n", &q, q);
    printf("new thread: %p %p\n", &new_thread, new_thread);
    printf("lock l: %p %p\n", &l, l);

    pthread_create(&new_thread, NULL, &thread_start, NULL);

    //pthread_join(new_thread,NULL);
//    usleep(10);     
    //if(x==0)return 0;
    pthread_mutex_lock(&l);
       deallocate(q);
    pthread_mutex_unlock(&l);

    pthread_mutex_lock(&l);
       x = 1;
       pthread_cond_timedwait(&cond, &l, &wait_time); // ANDREW: prevent deadlock
    pthread_mutex_unlock(&l);

    deallocate(p);
    pthread_join(new_thread, NULL);

	return 0;
}