[PATCH v8 4/8] nptl: Add C11 threads cnd_* functions

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

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,
tile{pro,gx}-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.

	* 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_2.27]: 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.
---
 ChangeLog                   | 25 +++++++++++++++++++++++++
 conform/data/threads.h-data |  8 ++++++++
 nptl/Makefile               |  3 ++-
 nptl/Versions               |  3 ++-
 nptl/cnd_broadcast.c        | 26 ++++++++++++++++++++++++++
 nptl/cnd_destroy.c          | 26 ++++++++++++++++++++++++++
 nptl/cnd_init.c             | 32 ++++++++++++++++++++++++++++++++
 nptl/cnd_signal.c           | 26 ++++++++++++++++++++++++++
 nptl/cnd_timedwait.c        | 29 +++++++++++++++++++++++++++++
 nptl/cnd_wait.c             | 27 +++++++++++++++++++++++++++
 sysdeps/nptl/threads.h      | 34 ++++++++++++++++++++++++++++++++++
 11 files changed, 237 insertions(+), 2 deletions(-)
 create mode 100644 nptl/cnd_broadcast.c
 create mode 100644 nptl/cnd_destroy.c
 create mode 100644 nptl/cnd_init.c
 create mode 100644 nptl/cnd_signal.c
 create mode 100644 nptl/cnd_timedwait.c
 create mode 100644 nptl/cnd_wait.c

diff --git a/conform/data/threads.h-data b/conform/data/threads.h-data
index 70b2fe0..d7c562e 100644
--- a/conform/data/threads.h-data
+++ b/conform/data/threads.h-data
@@ -16,6 +16,7 @@ type thrd_t
 type thrd_start_t
 type mtx_t
 type once_flag
+type cnd_t
 
 function int thrd_create (thrd_t*, thrd_start_t, void*)
 function int thrd_equal (thrd_t, thrd_t)
@@ -35,6 +36,13 @@ function void mtx_destroy (mtx_t*)
 
 function void call_once (once_flag*, void (*)(void))
 
+function int cnd_init (cnd_t*)
+function int cnd_signal (cnd_t*)
+function int cnd_broadcast (cnd_t*)
+function int cnd_wait (cnd_t*, mtx_t*)
+function int cnd_timedwait (cnd_t*, mtx_t*, const struct timespec*)
+function void cnd_destroy (cnd_t*)
+
 #include "time.h-data"
 
 #endif
diff --git a/nptl/Makefile b/nptl/Makefile
index e539df8..e13c07a 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -143,7 +143,8 @@ libpthread-routines = nptl-init vars events version pt-interp \
 		      thrd_create thrd_current thrd_detach thrd_equal \
 		      thrd_exit thrd_join thrd_sleep thrd_yield \
 		      mtx_destroy mtx_init mtx_lock mtx_timedlock \
-		      mtx_trylock mtx_unlock call_once
+		      mtx_trylock mtx_unlock call_once cnd_broadcast \
+		      cnd_destroy cnd_init cnd_signal cnd_timedwait cnd_wait
 #		      pthread_setuid pthread_seteuid pthread_setreuid \
 #		      pthread_setresuid \
 #		      pthread_setgid pthread_setegid pthread_setregid \
diff --git a/nptl/Versions b/nptl/Versions
index f09e295..0672286 100644
--- a/nptl/Versions
+++ b/nptl/Versions
@@ -269,7 +269,8 @@ libpthread {
   GLIBC_2.28 {
     thrd_create; thrd_current; thrd_detach; thrd_equal; thrd_exit; thrd_join;
     thrd_sleep; thrd_yield; mtx_init; mtx_lock; mtx_timedlock; mtx_trylock;
-    mtx_unlock; mtx_destroy; call_once;
+    mtx_unlock; mtx_destroy; call_once; cnd_broadcast; cnd_destroy; cnd_init;
+    cnd_signal; cnd_timedwait; cnd_wait; mtx_destroy;
   }
 
   GLIBC_PRIVATE {
diff --git a/nptl/cnd_broadcast.c b/nptl/cnd_broadcast.c
new file mode 100644
index 0000000..889f88e
--- /dev/null
+++ b/nptl/cnd_broadcast.c
@@ -0,0 +1,26 @@
+/* C11 thread conditional broadcast 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 "thrd_priv.h"
+
+int
+cnd_broadcast (cnd_t *cond)
+{
+  int err_code = __pthread_cond_broadcast ((pthread_cond_t*) cond);
+  return thrd_err_map (err_code);
+}
diff --git a/nptl/cnd_destroy.c b/nptl/cnd_destroy.c
new file mode 100644
index 0000000..37df9e9
--- /dev/null
+++ b/nptl/cnd_destroy.c
@@ -0,0 +1,26 @@
+/* C11 threads conditional destroy 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 "thrd_priv.h"
+#include "pthreadP.h"
+
+void
+cnd_destroy (cnd_t *cond)
+{
+  __pthread_cond_destroy ((pthread_cond_t *) cond);
+}
diff --git a/nptl/cnd_init.c b/nptl/cnd_init.c
new file mode 100644
index 0000000..2d9f5c0
--- /dev/null
+++ b/nptl/cnd_init.c
@@ -0,0 +1,32 @@
+/* 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), "cnd_t size");
+  _Static_assert (alignof (cnd_t) == alignof (pthread_cond_t),
+		  "cnd_t alignment");
+
+  int err_code = __pthread_cond_init ((pthread_cond_t *)cond, NULL);
+  return thrd_err_map (err_code);
+}
diff --git a/nptl/cnd_signal.c b/nptl/cnd_signal.c
new file mode 100644
index 0000000..8ae650b
--- /dev/null
+++ b/nptl/cnd_signal.c
@@ -0,0 +1,26 @@
+/* C11 threads conditional signal 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 "thrd_priv.h"
+
+int
+cnd_signal (cnd_t *cond)
+{
+  int err_code = __pthread_cond_signal ((pthread_cond_t *) cond);
+  return thrd_err_map (err_code);
+}
diff --git a/nptl/cnd_timedwait.c b/nptl/cnd_timedwait.c
new file mode 100644
index 0000000..75358fe
--- /dev/null
+++ b/nptl/cnd_timedwait.c
@@ -0,0 +1,29 @@
+/* C11 threads conditional timed wait 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 "thrd_priv.h"
+
+int
+cnd_timedwait (cnd_t *restrict cond, mtx_t *restrict mutex,
+	       const struct timespec* restrict time_point)
+{
+  int err_code = __pthread_cond_timedwait ((pthread_cond_t *) cond,
+					   (pthread_mutex_t *) mutex,
+					   time_point);
+  return thrd_err_map (err_code);
+}
diff --git a/nptl/cnd_wait.c b/nptl/cnd_wait.c
new file mode 100644
index 0000000..727d9bb
--- /dev/null
+++ b/nptl/cnd_wait.c
@@ -0,0 +1,27 @@
+/* C11 threads conditional wait implementaiton.
+   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 "thrd_priv.h"
+
+int
+cnd_wait (cnd_t *cond, mtx_t *mutex)
+{
+  int err_code = __pthread_cond_wait ((pthread_cond_t *) cond,
+				      (pthread_mutex_t *) mutex);
+  return thrd_err_map (err_code);
+}
diff --git a/sysdeps/nptl/threads.h b/sysdeps/nptl/threads.h
index 6c9c3ef..eb89b0a 100644
--- a/sysdeps/nptl/threads.h
+++ b/sysdeps/nptl/threads.h
@@ -57,6 +57,12 @@ typedef union
   long int __align __LOCK_ALIGNMENT;
 } mtx_t;
 
+typedef union
+{
+  char __size[__SIZEOF_PTHREAD_COND_T];
+  __extension__ long long int __align __LOCK_ALIGNMENT;
+} cnd_t;
+
 /* Threads functions.  */
 
 /* Create a new thread executing the function __FUNC.  Arguments for __FUNC
@@ -137,6 +143,34 @@ extern void mtx_destroy (mtx_t *__mutex);
    All calls must be made with the same __FLAGS object.  */
 extern void call_once (once_flag *__flag, void (*__func)(void));
 
+
+/* Condition variable functions.  */
+
+/* Initialize new condition variable pointed by __COND.  */
+extern int cnd_init (cnd_t *__cond);
+
+/* Unblock one thread that currently waits on condition variable pointed
+   by __COND.  */
+extern int cnd_signal (cnd_t *__cond);
+
+/* Unblock all threads currently waiting on condition variable pointed by
+   __COND.  */
+extern int cnd_broadcast (cnd_t *__cond);
+
+/* Block current thread on the condition variable pointed by __COND.  */
+extern int cnd_wait (cnd_t *__cond, mtx_t *__mutex);
+
+/* Block current thread on the condition variable until condition variable
+   pointed by __COND is signaled or time pointed by __TIME_POINT is
+   reached.  */
+extern int cnd_timedwait (cnd_t *__restrict __cond,
+			  mtx_t *__restrict __mutex,
+			  const struct timespec *__restrict __time_point);
+
+/* Destroy condition variable pointed by __cond and free all of its
+   resources.  */
+extern void cnd_destroy (cnd_t *__COND);
+
 __END_DECLS
 
 #endif /* _THREADS_H */
-- 
2.7.4