diff options
Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c')
-rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c | 71 |
1 files changed, 0 insertions, 71 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c b/nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c deleted file mode 100644 index a478ac18e3..0000000000 --- a/nptl/sysdeps/unix/sysv/linux/x86/elision-trylock.c +++ /dev/null @@ -1,71 +0,0 @@ -/* elision-trylock.c: Lock eliding trylock for pthreads. - Copyright (C) 2013-2014 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 <pthread.h> -#include <pthreadP.h> -#include <lowlevellock.h> -#include "hle.h" -#include <elision-conf.h> - -#define aconf __elision_aconf - -/* Try to elide a futex trylock. FUTEX is the futex variable. ADAPT_COUNT is - the adaptation counter in the mutex. */ - -int -__lll_trylock_elision (int *futex, short *adapt_count) -{ - /* Implement POSIX semantics by forbiding nesting - trylock. Sorry. After the abort the code is re-executed - non transactional and if the lock was already locked - return an error. */ - _xabort (_ABORT_NESTED_TRYLOCK); - - /* Only try a transaction if it's worth it. */ - if (*adapt_count <= 0) - { - unsigned status; - - if ((status = _xbegin()) == _XBEGIN_STARTED) - { - if (*futex == 0) - return 0; - - /* Lock was busy. Fall back to normal locking. - Could also _xend here but xabort with 0xff code - is more visible in the profiler. */ - _xabort (_ABORT_LOCK_BUSY); - } - - if (!(status & _XABORT_RETRY)) - { - /* Internal abort. No chance for retry. For future - locks don't try speculation for some time. */ - if (*adapt_count != aconf.skip_trylock_internal_abort) - *adapt_count = aconf.skip_trylock_internal_abort; - } - /* Could do some retries here. */ - } - else - { - /* Lost updates are possible, but harmless. */ - (*adapt_count)--; - } - - return lll_trylock (*futex); -} |