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PTHREAD_MUTEXATTR_GETPSHARELinux Programmer's MPTHREAD_MUTEXATTR_GETPSHARED(3)
NAME
       pthread_mutexattr_getpshared,  pthread_mutexattr_setpshared  -  get/set
       process-shared mutex attribute
SYNOPSIS
       #include <pthread.h>
       int pthread_mutexattr_getpshared(const pthread_mutexattr_t *attr,
                                        int *pshared);
       int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr,
                                        int pshared);
       Compile and link with -pthread.
DESCRIPTION
       These functions get and set the process-shared  attribute  in  a  mutex
       attributes  object.  This attribute must be appropriately set to ensure
       correct, efficient operation of a mutex created using  this  attributes
       object.
       The process-shared attribute can have one of the following values:
       PTHREAD_PROCESS_PRIVATE
              Mutexes  created  with  this  attributes object are to be shared
              only among threads in the  same  process  that  initialized  the
              mutex.   This  is the default value for the process-shared mutex
              attribute.
       PTHREAD_PROCESS_SHARED
              Mutexes created  with  this  attributes  object  can  be  shared
              between  any  threads  that have access to the memory containing
              the object, including threads in different processes.
       pthread_mutexattr_getpshared() places the value of  the  process-shared
       attribute  of  the  mutex  attributes object referred to by attr in the
       location pointed to by pshared.
       pthread_mutexattr_setpshared() sets the  value  of  the  process-shared
       attribute  of  the  mutex  attributes object referred to by attr to the
       value specified in pshared.
       If attr does not refer to an initialized mutex attributes  object,  the
       behavior is undefined.
RETURN VALUE
       On success, these functions return 0.  On error, they return a positive
       error number.
ERRORS
       pthread_mutexattr_setpshared() can fail with the following errors:
       EINVAL The value specified in pshared is invalid.
       ENOTSUP
              pshared is PTHREAD_PROCESS_SHARED but  the  implementation  does
              not support process-shared mutexes.
CONFORMING TO
       POSIX.1-2001, POSIX.1-2008.
SEE ALSO
       pthread_mutexattr_init(3), pthreads(7)
COLOPHON
       This page is part of release 4.15 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.
Linux                             2017-09-13   PTHREAD_MUTEXATTR_GETPSHARED(3)