/* elision-unlock.c: Commit an elided pthread lock.

   Copyright (C) 2015-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include "pthreadP.h"

#include "lowlevellock.h"

#include "htm.h"

int

__lll_unlock_elision (int *lock, short *adapt_count, int pshared)

{

#ifndef __SPE__

  /* When the lock was free we're in a transaction.  */

  if (*lock == 0)

    __libc_tend (0);

  else

    {

      /* Update adapt_count in the critical section to prevent a

	 write-after-destroy error as mentioned in BZ 20822.  The

	 following update of adapt_count has to be contained within

	 the critical region of the fall-back lock in order to not violate

	 the mutex destruction requirements.  */

      short __tmp = atomic_load_relaxed (adapt_count);

      if (__tmp > 0)

	atomic_store_relaxed (adapt_count, __tmp - 1);

      lll_unlock ((*lock), pshared);

    }

#else

  lll_unlock ((*lock), pshared);

#endif

  return 0;

}