#include <pthread.h>                                                            
#include <stdio.h>                                                              
#include <sys/types.h>                                                          
#include <unistd.h>                                                             
#include <string.h>                                                             
#include <stdlib.h>                                                             
                                                                                
void * func1(void * arg)                                                        
{                                                                               
        while(1) {                                                              
                sleep(1);                                                       
                printf("%p\n", pthread_self());                                 
        }                                                                       
}                                                                               
                                                                                
void * func2(void * arg)                                                        
{                                                                               
        while(1) {                                                              
                sleep(1);                                                       
                printf("\t%p\n", pthread_self());                               
        }                                                                       
}                                                                               
                                                                                
int main(int argc, char**argv)                                                  
{                                                                               
        pthread_t td;                                                           
        pthread_mutex_t mutex;                                                  
        pthread_mutex_init(&mutex, NULL);                                       
        pthread_mutex_lock(&mutex);                                             
        printf("%p owns mutex\n", pthread_self());                              
                                                                                
        pthread_create(&td, NULL, func1, NULL);                                 
        printf("Created thread %p\n", td);                                      
        sleep(10);                                                              
                                                                                
        int error = pthread_mutex_unlock(&mutex);                               
        if(error) {                                                             
                printf("%p does not own mutex!(error=%s)\n",                    
                    pthread_self(), strerror(error));                           
        }                                                                       
                                                                                
        exit(0);                                                                
}