nptl: Add C11 threads cnd_* functions

This patch adds the cnd_* definitions from C11 threads (ISO/IEC 9899:2011),
more specifically cnd_broadcast, cnd_destroy, cnd_init, cnd_signal,
cnd_timedwait, cnd_wait, and required types.

Mostly of the definitions are composed based on POSIX conterparts, and
cnd_t is also based on internal pthreads fields, but with distinct internal
layout to avoid possible issues with code interchange (such as trying to pass
POSIX structure on C11 functions and to avoid inclusion of pthread.h).  The
idea is to make it possible to share POSIX internal implementation for mostly
of the code making adjust where only required.

Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu,
arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu,
microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu,
powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu,
and x86_64-linux-gnu).

Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
arm-linux-gnueabhf, and powerpc64le-linux-gnu.

	[BZ #14092]
	* conform/data/threads.h-data (cnd_t): New type.
	(cnd_init): New function.
	(cnd_signal): Likewise.
	(cnd_broadcast): Likewise.
	(cnd_wait): Likewise.
	(cnd_timedwait): Likewise.
	(cnd_destroy): Likewise.
	* nptl/Makefile (libpthread-routines): Add cnd_broadcast,
	cnd_destroy, cnd_init, cnd_signal, cnd_timedwait, and cnd_wait
	object.
	* nptl/Versions (libpthread) [GLIBC_2.28]: Likewise.
	* nptl/cnd_broadcast.c: New file.
	* nptl/cnd_destroy.c: Likewise.
	* nptl/cnd_init.c: Likewise.
	* nptl/cnd_signal.c: Likewise.
	* nptl/cnd_timedwait.c: Likewise.
	* nptl/cnd_wait.c: Likewise.
	* sysdeps/nptl/threads.h (cnd_t): New type.
	(cnd_init): New prototype.
	(cnd_signa): Likewise.
	(cnd_broadcast): Likewise.
	(cnd_wait): Likewise.
	(cnd_timedwait): Likewise.
	(cnd_destroy): Likewise.

1 files changed, 33 insertions, 0 deletions

diff --git a/nptl/cnd_init.c b/nptl/cnd_init.c
new file mode 100644
index 0000000000..13f0f80a08
--- /dev/null
+++ b/nptl/cnd_init.c
@@ -0,0 +1,33 @@
+/* C11 thread conditional initialization implementation.
+   Copyright (C) 2018 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 <stdalign.h>
+
+#include "thrd_priv.h"
+
+int
+cnd_init (cnd_t *cond)
+{
+  _Static_assert (sizeof (cnd_t) == sizeof (pthread_cond_t),
+		  "(sizeof (cnd_t) != sizeof (pthread_cond_t)");
+  _Static_assert (alignof (cnd_t) == alignof (pthread_cond_t),
+		  "alignof (cnd_t) != alignof (pthread_cond_t)");
+
+  int err_code = __pthread_cond_init ((pthread_cond_t *)cond, NULL);
+  return thrd_err_map (err_code);
+}