--- /dev/null
+/* AArch64 internal mutex struct definitions.
+ Copyright (C) 2019-2020 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/>. */
+
+#ifndef _THREAD_MUTEX_INTERNAL_H
+#define _THREAD_MUTEX_INTERNAL_H 1
+
+struct __pthread_mutex_s
+{
+ int __lock __LOCK_ALIGNMENT;
+ unsigned int __count;
+ int __owner;
+ unsigned int __nusers;
+ /* KIND must stay at this position in the structure to maintain
+ binary compatibility with static initializers.
+
+ Concurrency notes:
+ The __kind of a mutex is initialized either by the static
+ PTHREAD_MUTEX_INITIALIZER or by a call to pthread_mutex_init.
+
+ After a mutex has been initialized, the __kind of a mutex is usually not
+ changed. BUT it can be set to -1 in pthread_mutex_destroy or elision can
+ be enabled. This is done concurrently in the pthread_mutex_*lock
+ functions by using the macro FORCE_ELISION. This macro is only defined
+ for architectures which supports lock elision.
+
+ For elision, there are the flags PTHREAD_MUTEX_ELISION_NP and
+ PTHREAD_MUTEX_NO_ELISION_NP which can be set in addition to the already
+ set type of a mutex. Before a mutex is initialized, only
+ PTHREAD_MUTEX_NO_ELISION_NP can be set with pthread_mutexattr_settype.
+
+ After a mutex has been initialized, the functions pthread_mutex_*lock can
+ enable elision - if the mutex-type and the machine supports it - by
+ setting the flag PTHREAD_MUTEX_ELISION_NP. This is done concurrently.
+ Afterwards the lock / unlock functions are using specific elision
+ code-paths. */
+ int __kind;
+ int __spins;
+ __pthread_list_t __list;
+};
+
+#define __PTHREAD_MUTEX_HAVE_PREV 1
+
+#define __PTHREAD_MUTEX_INITIALIZER(__kind) \
+ 0, 0, 0, 0, __kind, 0, { 0, 0 }
+
+#endif