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Subject: [Boost-users] [boost::mutex] Suspicious EINVAL error
From: Panagiotis Foteinos (pafotein_at_[hidden])
Date: 2011-04-01 19:57:52

Hello users.

I am running a single thread which locks and unlocks mutexes, and I get the
following error: *

             /usr/include/boost/thread/pthread/mutex.hpp:55: void
boost::mutex::lock(): Assertion `!pthread_mutex_lock(&m)' failed,

*after a boost::shared_mutex::lock() or a boost::shared_mutex::try_lock().

In fact, I checked the error code that pthread_mutex_lock(&m) returned and
it was the EINVAL error (code number 22).

The posix manual gives 2 possibilities for this error: 1) the mutex has not
been properly initialized, or 2) The *mutex* was created with the protocol
attribute having the value PTHREAD_PRIO_PROTECT and the calling thread's
priority is higher than the mutex's current priority ceiling. Sadly, the
mutex is correctly initialized. As far as possibility (2) is concerned, well
I cannot interpret it...

My code is pretty big, so I cannot provide a complete snippet, but roughly
(just in case it helps):

I have the following class:
class Vertex
      boost::shared_mutex mtx;


whose objects call Vertex::mtx->lock(), Vertex::mtx->unlock(),
Vertex::mtx->lock_shared(), and Vertex::mtx->unlock_shared().

The above error is produced whenever a specific object (residing in memory)
locks or even try_locks its mutex. It always happens for a specific object.

I am using the GNU C++ compiler 4.4.3 on Ubuntu x86_64.

I do realize that the information I provide in this email is little, but I,
being new in boost::mutexes and having spent so much time on it, decided to
give it a shot.

Best Regards,
Panagiotis Foteinos

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