/* Helper function for io_identity
   Copyright (C) 1996, 1999 Free Software Foundation, Inc.
   Written by Michael I. Bushnell, p/BSG.

   This file is part of the GNU Hurd.

   The GNU Hurd is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   The GNU Hurd is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */


#include <fshelp.h>
#include <hurd/ports.h>
#include <hurd/ihash.h>
#include <stddef.h>
#include <assert.h>

static struct port_class *idclass = 0;
static pthread_mutex_t idlock = PTHREAD_MUTEX_INITIALIZER;

struct idspec
{
  struct port_info pi;
  hurd_ihash_locp_t id_hashloc;
};

static struct hurd_ihash idhash
  = HURD_IHASH_INITIALIZER (offsetof (struct idspec, id_hashloc));

static void
id_clean (void *cookie)
{
  struct idspec *i = cookie;
  pthread_mutex_lock (&idlock);
  hurd_ihash_locp_remove (&idhash, i->id_hashloc);
  pthread_mutex_unlock (&idlock);
}

static void
id_initialize ()
{
  assert (!idclass);
  idclass = ports_create_class (id_clean, NULL);
}

error_t
fshelp_get_identity (struct port_bucket *bucket,
		     ino_t fileno,
		     mach_port_t *pt)
{
  struct idspec *i;
  error_t err = 0;

  pthread_mutex_lock (&idlock);
  if (!idclass)
    id_initialize ();

  i = hurd_ihash_find (&idhash, (hurd_ihash_key_t) fileno);
  if (i == NULL)
    {
      err = ports_create_port (idclass, bucket, sizeof (struct idspec), &i);
      if (err)
        goto lose;
      err = hurd_ihash_add (&idhash, (hurd_ihash_key_t) fileno, i);
      if (err)
        goto lose_port;

      *pt = ports_get_right (i);
      ports_port_deref (i);
    }
  else
    *pt = ports_get_right (i);

  /* Success!  */
  goto lose;

 lose_port:
  ports_destroy_right (i);
 lose:
  pthread_mutex_unlock (&idlock);
  return err;
}