PTHREAD_MUTEXATTR_GETPSHARED(3)<(/2a0>17-09<-a13h)ref="../3/PTHREAD_MUTEXATTR_GETPSHARED">PTHREAD_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 appropri-
          ately 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 ini-
               tialized 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 mem-
               ory containing the object, including threads in differ-
               ent 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.

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     PTHREAD_MUTEXATTR_GETPSHARED(3)<(/2a0>17-09<-a13h)ref="../3/PTHREAD_MUTEXATTR_GETPSHARED">PTHREAD_MUTEXATTR_GETPSHARED(3)

     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 implementa-
               tion 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 5.10 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/.

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