Pthread Mutex Init Bus Error

here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Getting bus error 10 with pthreads up vote 3 down vote favorite My command line tool keeps throwing the bus error: 10 message. Xcode debugger shows EXC_BAD_ACCESS message and highlights the function call that creates the thread. Manual debugging shows that the execution flow breaks at random positions inside the thread flow. I tried another compiler (gcc), but it ended up the same. Disabling pthread_mutex_lock() and pthread_mutex_unlock() doesn't help. I wrote this small example that reproduces the error. #include #include #include typedef struct thread_args { pthread_mutex_t* mutex; } thread_args; void* test(void* t_args) { printf("Thread initiated\n"); thread_args* args = (thread_args* )t_args; printf("Args casted\n"); pthread_mutex_lock(args->mutex); printf("Mutex locked\n"); pthread_mutex_unlock(args->mutex); printf("Mutex unlocked\n"); pthread_exit(NULL); } int main() { pthread_mutex_t mutex1; pthread_mutex_init(&mutex1, NULL); thread_args args; args.mutex = &mutex1; pthread_t* thread; printf("Initiating a thread\n"); pthread_create(thread, NULL, test, &args); return(0); } c multithreading debugging pthreads share|improve this question edited Jun 23 '15 at 19:57 Sourav Ghosh 71.1k1174130 asked Jun 23 '15 at 19:38 Eli Korvigo 3,4612730 add a comment| 3 Answers 3 active oldest votes up vote 2 down vote accepted I think, in your case, pthread_create(thread, NULL, test, &args); at this call, thread is a pointer and not allocated memory. So, essentially pthread_create() tries to write into uninitialized memory, which creates undefined behavior. Referring the man page of pthread_create() Before returning, a successful call to pthread_create() stores the ID of the new thread in the buffer pointed to by thread;.... Instead, you can do pthread_t thread; ... pthread_create(&thread, NULL, test, &args); share|improve this answer edited Jun 23 '15 at 19:46 answered Jun 23 '15 at 19:42 Sourav Ghosh 71.1k1174130 I always thought this is sort of errors result in se

here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up pthread bus error up vote 2 http://stackoverflow.com/questions/31011959/getting-bus-error-10-with-pthreads down vote favorite I'm doing an exercise. The goal is to make a program in C to crack DES encrypted password. Right now I have the following flow of execution: Load dictionary. Dictionary search. Brute force search of the first 4 characters. Dictionary search combined with brute force (searching for combinations). Only dictionary words of 7-6 characters. Brute force search of the first 5 characters. Dictionary http://stackoverflow.com/questions/8551267/pthread-bus-error search combined with brute force (searching for combinations). Only dictionary words of 5-4 characters. Brute force search of up to 8 characters. The program works fine, but I want to improve it by using multiple threads: 1st thread - main 2nd thread - dictionary and dictionary combined with brute force search 3rd thread - brute force search I've started by making a basic dictionary search thread function, but it fails with Bus Error (Mac OS X) where it should start reading words from the dictionary file. Same code works fine in the regular non- thread function... Here is the code: #include #include #include #include #define _XOPEN_SOURCE #define MAXLINE 40 #define MAXPASS 9 /* dictionary search thread function */ void * dictionary(void * argv) { /* initializing SALT */ char salt[3]; // defining salt (length is always 2 chars + "\0") strncpy(salt, argv, 2); // copying the first 2 characters from encrypted password to salt salt[2] = '\0'; // placing null character to make salt a string /* defining and initializing password */ char password[14]; strcpy(password, argv); /* defining candidate */ char candidate[MAXPASS]; /* opening file */ FILE *fp; if ((fp = fopen("/usr/s

the interface may not be implemented on Linux. Name pthread_mutex_destroy, pthread_mutex_init https://linux.die.net/man/3/pthread_mutex_init - destroy and initialize a mutex Synopsis #include int pthread_mutex_destroy(pthread_mutex_t *mutex); int pthread_mutex_init(pthread_mutex_t *restrict mutex, const pthread_mutexattr_t *restrict attr); pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; Description The pthread_mutex_destroy() function shall destroy the mutex object referenced by mutex; the mutex object becomes, in effect, uninitialized. An implementation may pthread mutex cause pthread_mutex_destroy() to set the object referenced by mutex to an invalid value. A destroyed mutex object can be reinitialized using pthread_mutex_init(); the results of otherwise referencing the object after it has been destroyed are undefined. It shall be safe to destroy an initialized mutex that pthread mutex init is unlocked. Attempting to destroy a locked mutex results in undefined behavior. The pthread_mutex_init() function shall initialize the mutex referenced by mutex with attributes specified by attr. If attr is NULL, the default mutex attributes are used; the effect shall be the same as passing the address of a default mutex attributes object. Upon successful initialization, the state of the mutex becomes initialized and unlocked. Only mutex itself may be used for performing synchronization. The result of referring to copies of mutex in calls to pthread_mutex_lock(), pthread_mutex_trylock(), pthread_mutex_unlock(), and pthread_mutex_destroy() is undefined. Attempting to initialize an already initialized mutex results in undefined behavior. In cases where default mutex attributes are appropriate, the macro PTHREAD_MUTEX_INITIALIZER can be used to initialize mutexes that are statically allocated. The effect shall be equivalent to dynamic initialization by a call to pthread_mutex_init()