X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=include%2Furcu%2Fstatic%2Furcu-signal.h;h=07768b340a768a30584bdf643ff14c61097a8203;hb=3d003c571cd461aba1935e5d21e1e04da7183970;hp=56730e17d449494f81ba41d4f00e86a0178f21f6;hpb=2a27e9319bacc9bc98f38afb7e4f050601ab979b;p=userspace-rcu.git

diff --git a/include/urcu/static/urcu-signal.h b/include/urcu/static/urcu-signal.h
index 56730e1..07768b3 100644
--- a/include/urcu/static/urcu-signal.h
+++ b/include/urcu/static/urcu-signal.h
@@ -1,31 +1,17 @@
+// SPDX-FileCopyrightText: 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+// SPDX-FileCopyrightText: 2009 Paul E. McKenney, IBM Corporation.
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
 #ifndef _URCU_SIGNAL_STATIC_H
 #define _URCU_SIGNAL_STATIC_H
 
 /*
- * urcu-signal-static.h
- *
  * Userspace RCU header.
  *
  * TO BE INCLUDED ONLY IN CODE THAT IS TO BE RECOMPILED ON EACH LIBURCU
  * RELEASE. See urcu.h for linking dynamically with the userspace rcu library.
  *
- * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- * Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
- *
- * This 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.
- *
- * This 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 this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
  * IBM's contributions to this file may be relicensed under LGPLv2 or later.
  */
 
@@ -34,6 +20,7 @@
 #include <unistd.h>
 #include <stdint.h>
 
+#include <urcu/debug.h>
 #include <urcu/config.h>
 #include <urcu/compiler.h>
 #include <urcu/arch.h>
@@ -42,7 +29,6 @@
 #include <urcu/list.h>
 #include <urcu/futex.h>
 #include <urcu/tls-compat.h>
-#include <urcu/debug.h>
 #include <urcu/static/urcu-common.h>
 #include <urcu/static/urcu-signal-nr.h>
 
@@ -64,16 +50,16 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_signal_reader);
 
 /*
  * Helper for _rcu_read_lock().  The format of urcu_signal_gp.ctr (as well as
- * the per-thread rcu_reader.ctr) has the upper bits containing a count of
- * _rcu_read_lock() nesting, and a lower-order bit that contains either zero
- * or URCU_GP_CTR_PHASE.  The cmm_barrier() ensures that the accesses in
+ * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
+ * _rcu_read_lock() nesting, and a single high-order URCU_BP_GP_CTR_PHASE bit
+ * that contains either zero or one.  The cmm_barrier() ensures that the accesses in
  * _rcu_read_lock() happen before the subsequent read-side critical section.
  */
 static inline void _urcu_signal_read_lock_update(unsigned long tmp)
 {
 	if (caa_likely(!(tmp & URCU_GP_CTR_NEST_MASK))) {
 		_CMM_STORE_SHARED(URCU_TLS(urcu_signal_reader).ctr, _CMM_LOAD_SHARED(urcu_signal_gp.ctr));
-		cmm_barrier();
+		cmm_smp_mb();
 	} else
 		_CMM_STORE_SHARED(URCU_TLS(urcu_signal_reader).ctr, tmp + URCU_GP_COUNT);
 }
@@ -109,13 +95,14 @@ static inline void _urcu_signal_read_lock(void)
  */
 static inline void _urcu_signal_read_unlock_update_and_wakeup(unsigned long tmp)
 {
+	unsigned long *ctr = &URCU_TLS(urcu_signal_reader).ctr;
+
 	if (caa_likely((tmp & URCU_GP_CTR_NEST_MASK) == URCU_GP_COUNT)) {
-		cmm_barrier();
-		_CMM_STORE_SHARED(URCU_TLS(urcu_signal_reader).ctr, tmp - URCU_GP_COUNT);
-		cmm_barrier();
+		uatomic_store(ctr, tmp - URCU_GP_COUNT, CMM_SEQ_CST);
 		urcu_common_wake_up_gp(&urcu_signal_gp);
-	} else
-		_CMM_STORE_SHARED(URCU_TLS(urcu_signal_reader).ctr, tmp - URCU_GP_COUNT);
+	} else {
+		uatomic_store(ctr, tmp - URCU_GP_COUNT, CMM_RELAXED);
+	}
 }
 
 /*