Assertion `mutex->__data.__owner

Assertion `mutex->__data.__owner

[trisha yad]

Dear All,

Today on my ARM Board one problem hit.
pthread_mutex_lock.c:62: __pthread_mutex_lock: Assertion
`mutex->__data.__owner == 0' failed.
This happen in pthread_mutex_lock.c.
May you pls let me know in which all cases it can happen.


int
__pthread_mutex_lock (mutex)
     pthread_mutex_t *mutex;
{
  assert (sizeof (mutex->__size) >= sizeof (mutex->__data));

  unsigned int type = PTHREAD_MUTEX_TYPE (mutex);
  if (__builtin_expect (type & ~PTHREAD_MUTEX_KIND_MASK_NP, 0))
    return __pthread_mutex_lock_full (mutex);

  pid_t id = THREAD_GETMEM (THREAD_SELF, tid);

  if (__builtin_expect (type, PTHREAD_MUTEX_TIMED_NP)
      == PTHREAD_MUTEX_TIMED_NP)
    {
    simple:
      /* Normal mutex.  */
      LLL_MUTEX_LOCK (mutex);
      assert (mutex->__data.__owner ==
0);<-------------------------------------------------Here.
    }
  else if (__builtin_expect (type == PTHREAD_MUTEX_RECURSIVE_NP, 1))
......

Thanks

Assertion `mutex->__data.__owner

[trisha yad]

Dear All,

Today on my ARM Board one problem hit.
pthread_mutex_lock.c:62: __pthread_mutex_lock: Assertion
`mutex->__data.__owner == 0' failed.
This happen in pthread_mutex_lock.c.
May you pls let me know in which all cases it can happen.


int
__pthread_mutex_lock (mutex)
     pthread_mutex_t *mutex;
{
  assert (sizeof (mutex->__size) >= sizeof (mutex->__data));

  unsigned int type = PTHREAD_MUTEX_TYPE (mutex);
  if (__builtin_expect (type & ~PTHREAD_MUTEX_KIND_MASK_NP, 0))
    return __pthread_mutex_lock_full (mutex);

  pid_t id = THREAD_GETMEM (THREAD_SELF, tid);

  if (__builtin_expect (type, PTHREAD_MUTEX_TIMED_NP)
      == PTHREAD_MUTEX_TIMED_NP)
    {
    simple:
      /* Normal mutex.  */
      LLL_MUTEX_LOCK (mutex);
      assert (mutex->__data.__owner ==
0);<-------------------------------------------------Here.
    }
  else if (__builtin_expect (type == PTHREAD_MUTEX_RECURSIVE_NP, 1))
......

Thanks

Re: Assertion `mutex->__data.__owner

[Carlos O'Donell]

On Thu, Nov 24, 2011 at 7:56 AM, trisha yad <trisha1march@gmail.com> wrote:
> Today on my ARM Board one problem hit.
> pthread_mutex_lock.c:62: __pthread_mutex_lock: Assertion
> `mutex->__data.__owner == 0' failed.
> This happen in pthread_mutex_lock.c.
> May you pls let me know in which all cases it can happen.

It should only happen if:
* the atomic operation was *not* atomic and you took a lock owned by
another thread.
* another thread accidentally corrupted the mutex by writing into it
without holding the lock e.g. buffer overrun/underrun etc.
* you have a compiler bug that causes the threading library to be
incorrectly compiled and violate the ordering requirements the code
needs to be atomic.

Is it reproducible?

Cheers,
Carlos.

Re: Assertion `mutex->__data.__owner

[Carlos O'Donell]

On Thu, Nov 24, 2011 at 7:56 AM, trisha yad <trisha1march@gmail.com> wrote:
> Today on my ARM Board one problem hit.
> pthread_mutex_lock.c:62: __pthread_mutex_lock: Assertion
> `mutex->__data.__owner == 0' failed.
> This happen in pthread_mutex_lock.c.
> May you pls let me know in which all cases it can happen.

It should only happen if:
* the atomic operation was *not* atomic and you took a lock owned by
another thread.
* another thread accidentally corrupted the mutex by writing into it
without holding the lock e.g. buffer overrun/underrun etc.
* you have a compiler bug that causes the threading library to be
incorrectly compiled and violate the ordering requirements the code
needs to be atomic.

Is it reproducible?

Cheers,
Carlos.