+// 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_QSBR_STATIC_H
#define _URCU_QSBR_STATIC_H
/*
- * urcu-qsbr-static.h
- *
* Userspace RCU QSBR 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.
*/
#include <unistd.h>
#include <stdint.h>
+#include <urcu/annotate.h>
+#include <urcu/debug.h>
#include <urcu/compiler.h>
#include <urcu/arch.h>
#include <urcu/system.h>
#include <urcu/list.h>
#include <urcu/futex.h>
#include <urcu/tls-compat.h>
-#include <urcu/debug.h>
+#include <urcu/static/urcu-common.h>
#ifdef __cplusplus
extern "C" {
* This is required to permit relinking with newer versions of the library.
*/
-enum rcu_state {
- RCU_READER_ACTIVE_CURRENT,
- RCU_READER_ACTIVE_OLD,
- RCU_READER_INACTIVE,
-};
+#define URCU_QSBR_GP_ONLINE (1UL << 0)
+#define URCU_QSBR_GP_CTR (1UL << 1)
-#define RCU_GP_ONLINE (1UL << 0)
-#define RCU_GP_CTR (1UL << 1)
+extern struct urcu_gp urcu_qsbr_gp;
-struct rcu_gp {
- /*
- * Global quiescent period counter with low-order bits unused.
- * Using a int rather than a char to eliminate false register
- * dependencies causing stalls on some architectures.
- */
- unsigned long ctr;
-
- int32_t futex;
-} __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
-
-extern struct rcu_gp rcu_gp;
-
-struct rcu_reader {
+struct urcu_qsbr_reader {
/* Data used by both reader and synchronize_rcu() */
unsigned long ctr;
/* Data used for registry */
unsigned int registered:1;
};
-extern DECLARE_URCU_TLS(struct rcu_reader, rcu_reader);
+extern DECLARE_URCU_TLS(struct urcu_qsbr_reader, urcu_qsbr_reader);
/*
* Wake-up waiting synchronize_rcu(). Called from many concurrent threads.
*/
-static inline void wake_up_gp(void)
+static inline void urcu_qsbr_wake_up_gp(void)
{
- if (caa_unlikely(_CMM_LOAD_SHARED(URCU_TLS(rcu_reader).waiting))) {
- _CMM_STORE_SHARED(URCU_TLS(rcu_reader).waiting, 0);
+ if (caa_unlikely(_CMM_LOAD_SHARED(URCU_TLS(urcu_qsbr_reader).waiting))) {
+ _CMM_STORE_SHARED(URCU_TLS(urcu_qsbr_reader).waiting, 0);
cmm_smp_mb();
- if (uatomic_read(&rcu_gp.futex) != -1)
+ if (uatomic_read(&urcu_qsbr_gp.futex) != -1)
return;
- uatomic_set(&rcu_gp.futex, 0);
+ uatomic_set(&urcu_qsbr_gp.futex, 0);
/*
* Ignoring return value until we can make this function
* return something (because urcu_die() is not publicly
* exposed).
*/
- (void) futex_noasync(&rcu_gp.futex, FUTEX_WAKE, 1,
+ (void) futex_noasync(&urcu_qsbr_gp.futex, FUTEX_WAKE, 1,
NULL, NULL, 0);
}
}
-static inline enum rcu_state rcu_reader_state(unsigned long *ctr)
+static inline enum urcu_state urcu_qsbr_reader_state(unsigned long *ctr,
+ cmm_annotate_t *group)
{
unsigned long v;
- v = CMM_LOAD_SHARED(*ctr);
+ v = uatomic_load(ctr, CMM_RELAXED);
+ cmm_annotate_group_mem_acquire(group, ctr);
+
if (!v)
- return RCU_READER_INACTIVE;
- if (v == rcu_gp.ctr)
- return RCU_READER_ACTIVE_CURRENT;
- return RCU_READER_ACTIVE_OLD;
+ return URCU_READER_INACTIVE;
+ if (v == urcu_qsbr_gp.ctr)
+ return URCU_READER_ACTIVE_CURRENT;
+ return URCU_READER_ACTIVE_OLD;
}
/*
* function meets the 10-line criterion for LGPL, allowing this function
* to be invoked directly from non-LGPL code.
*/
-static inline void _rcu_read_lock(void)
+static inline void _urcu_qsbr_read_lock(void)
{
- urcu_assert(URCU_TLS(rcu_reader).ctr);
+ urcu_assert_debug(URCU_TLS(urcu_qsbr_reader).ctr);
}
/*
* function meets the 10-line criterion for LGPL, allowing this function
* to be invoked directly from non-LGPL code.
*/
-static inline void _rcu_read_unlock(void)
+static inline void _urcu_qsbr_read_unlock(void)
{
- urcu_assert(URCU_TLS(rcu_reader).ctr);
+ urcu_assert_debug(URCU_TLS(urcu_qsbr_reader).ctr);
}
/*
* function meets the 10-line criterion for LGPL, allowing this function
* to be invoked directly from non-LGPL code.
*/
-static inline int _rcu_read_ongoing(void)
+static inline int _urcu_qsbr_read_ongoing(void)
{
- return URCU_TLS(rcu_reader).ctr;
+ return URCU_TLS(urcu_qsbr_reader).ctr;
}
/*
* This is a helper function for _rcu_quiescent_state().
* The first cmm_smp_mb() ensures memory accesses in the prior read-side
* critical sections are not reordered with store to
- * URCU_TLS(rcu_reader).ctr, and ensures that mutexes held within an
+ * URCU_TLS(urcu_qsbr_reader).ctr, and ensures that mutexes held within an
* offline section that would happen to end with this
- * rcu_quiescent_state() call are not reordered with
- * store to URCU_TLS(rcu_reader).ctr.
+ * urcu_qsbr_quiescent_state() call are not reordered with
+ * store to URCU_TLS(urcu_qsbr_reader).ctr.
*/
-static inline void _rcu_quiescent_state_update_and_wakeup(unsigned long gp_ctr)
+static inline void _urcu_qsbr_quiescent_state_update_and_wakeup(unsigned long gp_ctr)
{
- cmm_smp_mb();
- _CMM_STORE_SHARED(URCU_TLS(rcu_reader).ctr, gp_ctr);
- cmm_smp_mb(); /* write URCU_TLS(rcu_reader).ctr before read futex */
- wake_up_gp();
+ uatomic_store(&URCU_TLS(urcu_qsbr_reader).ctr, gp_ctr, CMM_SEQ_CST);
+
+ /* write URCU_TLS(urcu_qsbr_reader).ctr before read futex */
+ urcu_qsbr_wake_up_gp();
cmm_smp_mb();
}
* to be invoked directly from non-LGPL code.
*
* We skip the memory barriers and gp store if our local ctr already
- * matches the global rcu_gp.ctr value: this is OK because a prior
+ * matches the global urcu_qsbr_gp.ctr value: this is OK because a prior
* _rcu_quiescent_state() or _rcu_thread_online() already updated it
* within our thread, so we have no quiescent state to report.
*/
-static inline void _rcu_quiescent_state(void)
+static inline void _urcu_qsbr_quiescent_state(void)
{
unsigned long gp_ctr;
- urcu_assert(URCU_TLS(rcu_reader).registered);
- if ((gp_ctr = CMM_LOAD_SHARED(rcu_gp.ctr)) == URCU_TLS(rcu_reader).ctr)
+ urcu_assert_debug(URCU_TLS(urcu_qsbr_reader).registered);
+ gp_ctr = uatomic_load(&urcu_qsbr_gp.ctr, CMM_RELAXED);
+ if (gp_ctr == URCU_TLS(urcu_qsbr_reader).ctr)
return;
- _rcu_quiescent_state_update_and_wakeup(gp_ctr);
+ _urcu_qsbr_quiescent_state_update_and_wakeup(gp_ctr);
}
/*
* function meets the 10-line criterion for LGPL, allowing this function
* to be invoked directly from non-LGPL code.
*/
-static inline void _rcu_thread_offline(void)
+static inline void _urcu_qsbr_thread_offline(void)
{
- urcu_assert(URCU_TLS(rcu_reader).registered);
- cmm_smp_mb();
- CMM_STORE_SHARED(URCU_TLS(rcu_reader).ctr, 0);
- cmm_smp_mb(); /* write URCU_TLS(rcu_reader).ctr before read futex */
- wake_up_gp();
+ urcu_assert_debug(URCU_TLS(urcu_qsbr_reader).registered);
+ uatomic_store(&URCU_TLS(urcu_qsbr_reader).ctr, 0, CMM_SEQ_CST);
+ /* write URCU_TLS(urcu_qsbr_reader).ctr before read futex */
+ urcu_qsbr_wake_up_gp();
cmm_barrier(); /* Ensure the compiler does not reorder us with mutex */
}
* function meets the 10-line criterion for LGPL, allowing this function
* to be invoked directly from non-LGPL code.
*/
-static inline void _rcu_thread_online(void)
+static inline void _urcu_qsbr_thread_online(void)
{
- urcu_assert(URCU_TLS(rcu_reader).registered);
+ unsigned long *pctr = &URCU_TLS(urcu_qsbr_reader).ctr;
+ unsigned long ctr;
+
+ urcu_assert_debug(URCU_TLS(urcu_qsbr_reader).registered);
cmm_barrier(); /* Ensure the compiler does not reorder us with mutex */
- _CMM_STORE_SHARED(URCU_TLS(rcu_reader).ctr, CMM_LOAD_SHARED(rcu_gp.ctr));
+ ctr = uatomic_load(&urcu_qsbr_gp.ctr, CMM_RELAXED);
+ cmm_annotate_mem_acquire(&urcu_qsbr_gp.ctr);
+ uatomic_store(pctr, ctr, CMM_RELAXED);
cmm_smp_mb();
}
projects / urcu.git / blobdiff