#include<stdio.h>
#include<pthread.h>
#include<errno.h>
pthread_mutex_t mutex;
void *threadfun1(void *arg)
{
printf("thread 1 started\n");
pthread_mutex_lock(&mutex);
printf("thread 1 acquired mutex\n");
pthread_exit(NULL);
}
void recover()
{
printf("data recovered\n");
pthread_mutex_consistent_np(&mutex);// making invalid mutex to valid mutex
pthread_mutex_unlock(&mutex);// unlockkiing the mutex object so that anybody can access that mutex
printf("made a valid mutex and unlocked\n");
}
void *threadfun2(void *arg)
{
int ret;
sleep(1);
ret = pthread_mutex_lock(&mutex);
printf("thread 2 started \n");
if(ret == EOWNERDEAD){// write this in all the threads, which executes 1st will sove the issues of mutex.
printf("owner dead\n");
recover();
}
pthread_mutex_lock(&mutex);
printf("thread 2 acquired mutex\n");
pthread_mutex_unlock(&mutex);
printf("thread 2 release mutex object\n");
return NULL;
}
int main()
{
pthread_t t1, t2;
void *res;
pthread_mutexattr_t attr;
pthread_mutexattr_init(&attr);
pthread_mutexattr_setrobust_np(&attr, PTHREAD_MUTEX_ROBUST_NP);
pthread_mutex_init(&mutex, &attr);// dynamically assigning
pthread_create(&t1,NULL,threadfun1,NULL);
pthread_create(&t2,NULL,threadfun2,NULL);
pthread_join(t1, &res);
pthread_join(t2, &res);
return 0;
}
