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/* Copyright (C) 2016 Free Software Foundation, Inc.
   Contributed by Agustina Arzille <avarzille@riseup.net>, 2016.

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

   This program 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 Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this program; if not, see
   <http://www.gnu.org/licenses/>.
*/

#include <pthread.h>
#include <stdlib.h>
#include <assert.h>
#include <pt-internal.h>
#include "pt-mutex.h"
#include <hurdlock.h>

int __pthread_mutex_transfer_np (pthread_mutex_t *mtxp, pthread_t th)
{
  struct __pthread *self = _pthread_self ();
  struct __pthread *pt = __pthread_getid (th);

  if (!pt)
    return (ESRCH);
  else if (pt == self)
    return (0);

  int ret = 0;
  int flags = mtxp->__flags & GSYNC_SHARED;

  switch (MTX_TYPE (mtxp))
    {
      case PT_MTX_NORMAL:
        break;

      case PT_MTX_RECURSIVE:
      case PT_MTX_ERRORCHECK:
        if (!mtx_owned_p (mtxp, self, flags))
          ret = EPERM;
        else
          mtx_set_owner (mtxp, pt, flags);

        break;

      case PT_MTX_NORMAL     | PTHREAD_MUTEX_ROBUST:
      case PT_MTX_RECURSIVE  | PTHREAD_MUTEX_ROBUST:
      case PT_MTX_ERRORCHECK | PTHREAD_MUTEX_ROBUST:
        /* Note that this can be used to transfer an inconsistent
         * mutex as well. The new owner will still have the same
         * flags as the original. */
        if (mtxp->__owner_id != self->thread ||
            (int)(mtxp->__lock & LLL_OWNER_MASK) != __getpid ())
          ret = EPERM;
        else
          mtxp->__owner_id = pt->thread;

        break;

      default:
        ret = EINVAL;
    }

  return (ret);
}

weak_alias (__pthread_mutex_transfer_np, pthread_mutex_transfer_np)