NAME    [Toc]    [Back]

       pthread_attr_init - Initializes a thread attributes object

SYNOPSIS    [Toc]    [Back]

       #include <pthread.h>

       int pthread_attr_init(
               pthread_attr_t *attr );

LIBRARY    [Toc]    [Back]

       DECthreads POSIX 1003.1c Library (libpthread.so)

STANDARDS    [Toc]    [Back]

       Interfaces documented on this reference  page  conform  to
       industry standards as follows:

       IEEE  Std  1003.1c-1995,  POSIX System Application Program
       Interface

PARAMETERS    [Toc]    [Back]

       Address of a thread attributes object to be initialized.

DESCRIPTION    [Toc]    [Back]

       This routine  initializes  the  thread  attributes  object
       specified  by  the  attr  argument  with  a set of default
       attribute values. A thread attributes object  is  used  to
       specify  the  attributes  of one or more threads when they
       are created. The attributes object created by this routine
       is used only in calls to the pthread_create(3) routine.

       The  following routines change individual attributes of an
       initialized thread attributes object:  pthread_attr_setdetachstate
  pthread_attr_setguardsize_np  pthread_attr_setinheritsched
                    pthread_attr_setschedparam
       pthread_attr_setschedpolicy          pthread_attr_setscope
       pthread_attr_setstackaddr pthread_attr_setstacksize

       The attributes of the thread attributes  object  are  initialized
  to  default  values.  The  default value of each
       attribute is discussed in the  reference  description  for
       each routine listed above.

       When  a  thread  attributes  object  is  used  to create a
       thread, the object's attribute values determine the  characteristics
  of  the  new thread. Thus, attributes objects
       act as additional arguments to thread  creation.  Changing
       the  attributes  of  a  thread  attributes object does not
       affect any threads that were previously created using that
       attributes object.

       You  can  use the same thread attributes object in successive
 calls to pthread_create(3), from  any  thread.  (However,
  you  cannot use the same value of the stack address
       attribute to create multiple threads that might  run  concurrently;
 threads cannot share a stack.) If more than one
       thread might change the attributes in a shared  attributes
       object,  your  program  must  use  a  mutex to protect the
       integrity of the attributes object's contents.

       When you set the scheduling policy or  scheduling  parameters,
  or  both,  in  a thread attributes object, you must
       disable scheduling inheritance if you want the  scheduling
       attributes you set to be used at thread creation.  To disable
  scheduling  inheritance,  before  creating  the  new
       thread  use  the  pthread_attr_setinheritsched  routine to
       specify the value PTHREAD_EXPLICIT_SCHED for  the  inherit
       argument.

RETURN VALUES    [Toc]    [Back]

       If an error condition occurs, the thread attributes object
       cannot be used, and this routine returns an integer  value
       indicating  the type of error.  Possible return values are
       as follows: Successful completion.  The value specified by
       attr  is  not  a valid thread attributes object.  Insufficient
 memory exists to initialize  the  thread  attributes
       object.

ERRORS    [Toc]    [Back]

       None

SEE ALSO    [Toc]    [Back]

       Functions:   pthread_attr_destroy(3),  pthread_attr_setdetachstate(3),                pthread_attr_setguardsize(3),
       pthread_attr_setinheritsched(3),    pthread_attr_setschedparam(3),                  pthread_attr_setschedpolicy(3),
       pthread_attr_setscope(3),    pthread_attr_setstackaddr(3),
       pthread_attr_setstacksize(3), pthread_create(3)

       Manuals: Guide to DECthreads and Programmer's Guide



                                             pthread_attr_init(3)