Manual Pages for UNIX Operating System command usage for man pthread_mutex_init

Standard C Library Functions               pthread_mutex_init(3C)



NAME
     pthread_mutex_init, pthread_mutex_destroy  -  initialize  or
     destroy a mutex

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

     int pthread_mutex_init(pthread_mutex_t *restrict mutex,
          const pthread_mutexattr_t *restrict attr);


     int pthread_mutex_destroy(pthread_mutex_t *mutex);


     pthread_mutex_t mutex= PTHREAD_MUTEX_INITIALIZER;


DESCRIPTION
     The  pthread_mutex_init()  function  initializes  the  mutex
     referenced  by  mutex  with attributes specified by attr. If
     attr is  NULL, the default mutex attributes  are  used;  the
     effect is the same as passing the address of a default mutex
     attributes object. Upon successful initialization, the state
     of the mutex becomes initialized and unlocked.


     Except for  robust  mutexes,  attempting  to  initialize  an
     already initialized mutex results in undefined behavior.


     The  pthread_mutex_destroy()  function  destroys  the  mutex
     object  referenced  by  mutex;  the mutex object becomes, in
     effect, uninitialized. A destroyed mutex object can  be  re-
     initialized  using pthread_mutex_init(); the results of oth-
     erwise referencing the object after it  has  been  destroyed
     are undefined.


     It is safe to destroy an initialized mutex that is unlocked.
     Attempting  to  destroy  a locked 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   is
     equivalent   to   dynamic   initialization   by  a  call  to
     pthread_mutex_init() with parameter attr specified as  NULL,
     except that no error checks are performed.





SunOS 5.11          Last change: 11 Nov 2008                    1






Standard C Library Functions               pthread_mutex_init(3C)



RETURN VALUES
     If     successful,     the     pthread_mutex_init()      and
     pthread_mutex_destroy()  functions  return  0. Otherwise, an
     error number is returned to indicate the error.

ERRORS
     The pthread_mutex_init() function will fail if:

     EAGAIN    The system lacked the necessary  resources  (other
               than memory) to initialize another mutex.


     EBUSY     An attempt was detected to  re-initialize a robust
               mutex  previously  initialized  but  not  yet des-
               troyed. See pthread_mutexattr_setrobust(3C).


     EINVAL    An attempt was detected to re-initialize a  robust
               mutex  previously initialized with a different set
               of                 attributes.                 See
               pthread_mutexattr_setrobust(3C).


     ENOMEM    Insufficient  memory  exists  to  initialize   the
               mutex.


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



     The pthread_mutex_init() function may fail if:

     EBUSY     An  attempt  was  detected  to  re-initialize  the
               object  referenced  by  mutex,  a mutex previously
               initialized but not yet destroyed.


     EINVAL    The value specified by attr or mutex is invalid.



     The pthread_mutex_destroy() function may fail if:

     EBUSY     An attempt was  detected  to  destroy  the  object
               referenced  by  mutex while it is locked or refer-
               enced  (for  example,  while  being  used   in   a
               pthread_cond_wait(3C)                           or
               pthread_cond_timedwait(3C)) by another thread.





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Standard C Library Functions               pthread_mutex_init(3C)



     EINVAL    The value specified by mutex is invalid.


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



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|
    | Standard                    | See standards(5).           |
    |_____________________________|_____________________________|


SEE ALSO
     pthread_cond_wait(3C),               pthread_mutex_lock(3C),
     pthread_mutexattr_setprioceiling(3C),
     pthread_mutexattr_setprotocol(3C),
     pthread_mutexattr_setpshared(3C),
     pthread_mutexattr_setrobust(3C),
     pthread_mutexattr_settype(3C),    attributes(5),   mutex(5),
     standards(5)



























SunOS 5.11          Last change: 11 Nov 2008                    3