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/*

 *  $Id: semaphorecreatesupp.c,v 1.2 2001-09-27 11:59:17 chris Exp $

 */

#include <stdarg.h>

#include <errno.h>

#include <fcntl.h>

#include <pthread.h>

#include <semaphore.h>

#include <limits.h>

#include <rtems/system.h>

#include <rtems/score/object.h>

#include <rtems/posix/semaphore.h>

#include <rtems/posix/time.h>

#include <rtems/posix/seterr.h>

#ifndef PATH_MAX

#define PATH_MAX 1024

#endif

/*PAGE

 *

 *  _POSIX_Semaphore_Create_support

 *

 *  This routine does the actual creation and initialization of

 *  a poxix semaphore.  It is a support routine for sem_init and

 *  sem_open.

 */

int _POSIX_Semaphore_Create_support(

  const char                *name,

  int                        pshared,

  unsigned int               value,

  POSIX_Semaphore_Control  **the_sem

)

{

  POSIX_Semaphore_Control   *the_semaphore;

  CORE_semaphore_Attributes *the_sem_attr;

  _Thread_Disable_dispatch();

  /* Sharing semaphores among processes is not currently supported */

  if (pshared != 0) {

    _Thread_Enable_dispatch();

    set_errno_and_return_minus_one( ENOSYS );

  }

  if ( name ) {

    if( strlen(name) > PATH_MAX ) {

      _Thread_Enable_dispatch();

      set_errno_and_return_minus_one( ENAMETOOLONG );

    }

  }

  the_semaphore = _POSIX_Semaphore_Allocate();

  if ( !the_semaphore ) {

    _Thread_Enable_dispatch();

    set_errno_and_return_minus_one( ENOSPC );

  }

#if defined(RTEMS_MULTIPROCESSING)

  if ( pshared == PTHREAD_PROCESS_SHARED &&

       !( _Objects_MP_Allocate_and_open( &_POSIX_Semaphore_Information, 0,

                            the_semaphore->Object.id, FALSE ) ) ) {

    _POSIX_Semaphore_Free( the_semaphore );

    _Thread_Enable_dispatch();

    set_errno_and_return_minus_one( EAGAIN );

  }

#endif

  the_semaphore->process_shared  = pshared;

  if ( name ) {

    the_semaphore->named = TRUE;

    the_semaphore->open_count = 1;

    the_semaphore->linked = TRUE;

  }

  else

    the_semaphore->named = FALSE;

  the_sem_attr = &the_semaphore->Semaphore.Attributes;

  /*

   *  POSIX does not appear to specify what the discipline for

   *  blocking tasks on this semaphore should be.  It could somehow

   *  be derived from the current scheduling policy.  One

   *  thing is certain, no matter what we decide, it won't be

   *  the same as  all other POSIX implementations. :)

   */

  the_sem_attr->discipline = CORE_SEMAPHORE_DISCIPLINES_FIFO;

  /*

   *  This effectively disables limit checking.

   */

  the_sem_attr->maximum_count = 0xFFFFFFFF;

  _CORE_semaphore_Initialize(

    &the_semaphore->Semaphore,

    OBJECTS_POSIX_SEMAPHORES,

    the_sem_attr,

    value,

    NULL                 /* multiprocessing is not supported */

  );

  /*

   *  Make the semaphore available for use.

   */

  _Objects_Open(

    &_POSIX_Semaphore_Information,

    &the_semaphore->Object,

    (char *) name

  );

  *the_sem = the_semaphore;

#if defined(RTEMS_MULTIPROCESSING)

  if ( pshared == PTHREAD_PROCESS_SHARED )

    _POSIX_Semaphore_MP_Send_process_packet(

      POSIX_SEMAPHORE_MP_ANNOUNCE_CREATE,

      the_semaphore->Object.id,

      (char *) name,

    );

#endif

  _Thread_Enable_dispatch();

  return 0;

}