/sys$common/syshlp/helplib.hlb DCE_THREADS, Application Routines, pthread_attr_setinheritsched  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  NAME

   pthread_attr_setinheritsched - Changes the inherit scheduling attribute

  SYNOPSIS

      #include <pthread.h>

      int pthread_attr_setinheritsched( pthread_attr_t attr,
                                        int inherit );

  PARAMETERS

      attr                Thread attributes object to be modified.

      inherit             New value for the inherit scheduling attribute.
                          Valid values are as follows:

                          PTHREAD_INHERIT_SCHED
                                  This is the default value. The created
                                  thread inherits the current priority
                                  and scheduling policy of the thread
                                  calling pthread_create().

                          PTHREAD_DEFAULT_SCHED
                                  The created thread starts execution with
                                  the priority and scheduling policy stored
                                  in the thread attributes object.

  DESCRIPTION

  The pthread_attr_setinheritsched() routine changes the inherit scheduling
  attribute of thread creation.  The inherit scheduling attribute specifies
  whether threads created using the specified thread attributes object
  inherit the scheduling attributes of the creating thread, or use the
  scheduling attributes stored in the thread attributes object that is
  passed to pthread_create().

  The first thread in an application that is not created by an explicit
  call to pthread_create() has a scheduling policy of SCHED_OTHER.  (See
  the pthread_attr_setprio() and pthread_attr_setsched() routines for more
  information on valid priority values and valid scheduling policy values,
  respectively.)

  Inheriting scheduling attributes (instead of using the scheduling attri-
  butes stored in the attributes object) is useful when a thread is creat-
  ing several helper threads-threads that are intended to work closely
  with the creating thread to cooperatively solve the same problem. For
  example, inherited scheduling attributes ensure that helper threads
  created in a sort routine execute with the same priority as the calling
  thread.

  RETURN VALUES

  If the function fails, -1 is returned, and errno may be set to one of
  the following values:

    Return   Error      Description
    ___________________________________________________________
    0                   Successful completion.

    -1       [EINVAL]   The value specified by attr is invalid.

    -1       [EINVAL]   The value specified by inherit is invalid.

  RELATED INFORMATION

      FUNCTIONS:  pthread_attr_create
                  pthread_attr_getinheritsched
                  pthread_attr_setprio
                  pthread_attr_setsched
                  pthread_create