Standard C Library Functions
                             pthreadmutexattrgetprioceiling(3C)



NAME
     pthreadmutexattrgetprioceiling,
     pthreadmutexattrsetprioceiling  -  get  or set prioceiling
     attribute of mutex attribute object

SYNOPSIS
     cc -mt [ flag... ] file... -lpthread [ library... ]
     #include 

     int pthreadmutexattrgetprioceiling(
          const pthreadmutexattrt *restrict attr,
          int *restrict prioceiling);


     int pthreadmutexattrsetprioceiling(pthreadmutexattrt *attr,
          int prioceiling);


DESCRIPTION
     The          pthreadmutexattrgetprioceiling()          and
     pthreadmutexattrsetprioceiling()  functions, respectively,
     get and set the priority ceiling attribute of a mutex attri-
     bute object pointed to by attr, which was previously created
     by the pthreadmutexattrinit() function.


     The prioceiling attribute contains the priority  ceiling  of
     initialized  mutexes.  The  values  of  prioceiling  must be
     within the range of priorities defined by SCHEDFIFO.


     The prioceiling attribute defines the  priority  ceiling  of
     initialized  mutexes, which is the minimum priority level at
     which the critical section guarded by the mutex is executed.
     In  order  to avoid priority inversion, the priority ceiling
     of the mutex must be set to a priority higher than or  equal
     to  the  highest  priority  of all the threads that may lock
     that mutex.


     The ceiling value should be drawn from the range of  priori-
     ties  for the SCHEDFIFO policy. When a thread acquires such
     a mutex, the policy  of  the  thread  at  mutex  acquisition
     should  match  that from which the ceiling value was derived
     (SCHEDFIFO, in this  case).     If  a  thread  changes  its
     scheduling   policy  while  holding  a  ceiling  mutex,  the
     behavior of pthreadmutexlock() and  pthreadmutexunlock()
     on this mutex is undefined. See pthreadmutexlock(3C).

RETURN VALUES




SunOS 5.11           Last change: 1 Apr 2008                    1






Standard C Library Functions
                             pthreadmutexattrgetprioceiling(3C)



     Upon          successful           completion,           the
     pthreadmutexattrgetprioceiling()                       and
     pthreadmutexattrsetprioceiling() functions return  0. Oth-
     erwise, an error number is returned to indicate the error.

ERORS
     The pthreadmutexattrsetprioceiling()  function  will  fail
     if:

     EINVAL    The value specified by attr is NUL or prioceiling
               is invalid.



     The          pthreadmutexattrgetprioceiling()          and
     pthreadmutexattrsetprioceiling() functions may fail if:

     EINVAL    The value specified  by  attr  or  prioceiling  is
               invalid.


     EPERM     The caller does not have the privilege to  perform
               the operation.


ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Committed                   
    
     MT-Level                     MT-Safe                     
    
     Standard                     See standards(5).           
    


SEE ALSO
     pthreadcondinit(3C),                   pthreadcreate(3C),
     pthreadmutexinit(3C),              pthreadmutexlock(3C),
     schedgetprioritymin(3C), attributes(5), standards(5)








SunOS 5.11           Last change: 1 Apr 2008                    2






Standard C Library Functions
                             pthreadmutexattrgetprioceiling(3C)






















































SunOS 5.11           Last change: 1 Apr 2008                    3