NAME

       pthread_mutexattr_getpshared, pthread_mutexattr_setpshared - get/set process-shared mutex attribute

LIBRARY

       POSIX threads library (libpthread, -lpthread)

SYNOPSIS

       #include <pthread.h>

       int pthread_mutexattr_getpshared(
                             const pthread_mutexattr_t *restrict attr,
                             int *restrict pshared);
       int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr,
                             int pshared);

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.

STANDARDS

       POSIX.1-2008.

HISTORY

       POSIX.1-2001.

SEE ALSO

       pthread_mutexattr_init(3), pthreads(7)

Linux man-pages 6.9.1                              2024-05-02                    pthread_mutexattr_getpshared(3)