This is the mail archive of the gcc-bugs@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[Bug libgomp/51249] semaphore implemetation for linux leaves threads blocked


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51249

Alan Modra <amodra at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011-11-21
         AssignedTo|unassigned at gcc dot       |amodra at gmail dot com
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #1 from Alan Modra <amodra at gmail dot com> 2011-11-21 03:07:04 UTC ---
What's more, the mutex implementation has a similar problem. 
libgomp/config/linux/mutex.c gomp_mutex_lock_slow uses a value of 2 in the
mutex to flag that threads are waiting on the mutex, similar to sem.c use of -1
in sem.  When two or more threads are waiting it is possible to clear the flag,
wake one thread but leave the other blocked forever.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]