| /* Default read-write lock implementation 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 __RWLOCK_INTERNAL_H |
| #define __RWLOCK_INTERNAL_H |
| |
| #include <bits/endian.h> |
| |
| /* Generic struct for both POSIX read-write lock. New ports are expected |
| to use the default layout, however archictetures can redefine it to add |
| arch-specific extensions (such as lock-elision). The struct have a size |
| of 32 bytes on both LP32 and LP64 architectures. */ |
| |
| struct __pthread_rwlock_arch_t |
| { |
| unsigned int __readers; |
| unsigned int __writers; |
| unsigned int __wrphase_futex; |
| unsigned int __writers_futex; |
| unsigned int __pad3; |
| unsigned int __pad4; |
| /* FLAGS must stay at its position in the structure to maintain |
| binary compatibility. */ |
| #if __BYTE_ORDER == __BIG_ENDIAN |
| unsigned char __pad1; |
| unsigned char __pad2; |
| unsigned char __shared; |
| unsigned char __flags; |
| #else |
| unsigned char __flags; |
| unsigned char __shared; |
| unsigned char __pad1; |
| unsigned char __pad2; |
| #endif |
| int __cur_writer; |
| }; |
| |
| #if __BYTE_ORDER == __BIG_ENDIAN |
| # define __PTHREAD_RWLOCK_INITIALIZER(__flags) \ |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, __flags, 0 |
| #else |
| # define __PTHREAD_RWLOCK_INITIALIZER(__flags) \ |
| 0, 0, 0, 0, 0, 0, __flags, 0, 0, 0, 0 |
| #endif |
| |
| #endif |