glibc/sysdeps/unix/sysv/linux/s390/elision-unlock.c

39 lines
1.3 KiB
C

/* Commit an elided pthread lock.
Copyright (C) 2014-2015 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>
int
__lll_unlock_elision(int *futex, int private)
{
/* If the lock is free, we elided the lock earlier. This does not
necessarily mean that we are in a transaction, because the user code may
have closed the transaction, but that is impossible to detect reliably. */
if (*futex == 0)
{
__asm__ volatile (".machinemode \"zarch_nohighgprs\"\n\t"
".machine \"all\""
: : : "memory");
__builtin_tend();
}
else
lll_unlock ((*futex), private);
return 0;
}