1 files changed, 61 insertions, 0 deletions
diff --git a/sysdeps/nptl/bits/struct_rwlock.h b/sysdeps/nptl/bits/struct_rwlock.h
new file mode 100644
index 0000000000..bb63028a46
--- /dev/null
+++ b/sysdeps/nptl/bits/struct_rwlock.h
@@ -0,0 +1,61 @@
+/* Default read-write lock implementation struct definitions.
+   Copyright (C) 2019 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