*
* Userspace RCU library
*
- * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ * Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
*
- * Distributed under GPLv2
+ * 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
+#include <poll.h>
+#include "urcu-static.h"
+/* Do not #define _LGPL_SOURCE to ensure we can emit the wrapper symbols */
#include "urcu.h"
pthread_mutex_t urcu_mutex = PTHREAD_MUTEX_INITIALIZER;
}
#ifdef DEBUG_FULL_MB
+#ifdef HAS_INCOHERENT_CACHES
static void force_mb_single_thread(struct reader_registry *index)
{
smp_mb();
}
+#endif /* #ifdef HAS_INCOHERENT_CACHES */
static void force_mb_all_threads(void)
{
smp_mb();
}
-#else
-
+#else /* #ifdef DEBUG_FULL_MB */
+#ifdef HAS_INCOHERENT_CACHES
static void force_mb_single_thread(struct reader_registry *index)
{
assert(registry);
}
smp_mb(); /* read ->need_mb before ending the barrier */
}
+#endif /* #ifdef HAS_INCOHERENT_CACHES */
static void force_mb_all_threads(void)
{
}
smp_mb(); /* read ->need_mb before ending the barrier */
}
-#endif
+#endif /* #else #ifdef DEBUG_FULL_MB */
void wait_for_quiescent_state(void)
{
* Wait for each thread urcu_active_readers count to become 0.
*/
for (index = registry; index < registry + num_readers; index++) {
+#ifndef HAS_INCOHERENT_CACHES
+ while (rcu_old_gp_ongoing(index->urcu_active_readers))
+ cpu_relax();
+#else /* #ifndef HAS_INCOHERENT_CACHES */
int wait_loops = 0;
/*
* BUSY-LOOP. Force the reader thread to commit its
cpu_relax();
}
}
+#endif /* #else #ifndef HAS_INCOHERENT_CACHES */
}
}
* Ensured by STORE_SHARED and LOAD_SHARED.
*/
+ /*
+ * Current RCU formal verification model assumes sequential execution of
+ * the write-side. Add core synchronization instructions. Can be removed
+ * if the formal model is extended to prove that reordering is still
+ * correct.
+ */
+ sync_core(); /* Formal model assumes serialized execution */
+
/*
* Wait for previous parity to be empty of readers.
*/
* Ensured by STORE_SHARED and LOAD_SHARED.
*/
+ sync_core(); /* Formal model assumes serialized execution */
+
switch_next_urcu_qparity(); /* 1 -> 0 */
/*
* Ensured by STORE_SHARED and LOAD_SHARED.
*/
+ sync_core(); /* Formal model assumes serialized execution */
+
/*
* Wait for previous parity to be empty of readers.
*/
internal_urcu_unlock();
}
-void urcu_add_reader(pthread_t id)
+/*
+ * library wrappers to be used by non-LGPL compatible source code.
+ */
+
+void rcu_read_lock(void)
+{
+ _rcu_read_lock();
+}
+
+void rcu_read_unlock(void)
+{
+ _rcu_read_unlock();
+}
+
+void *rcu_dereference(void *p)
+{
+ return _rcu_dereference(p);
+}
+
+void *rcu_assign_pointer_sym(void **p, void *v)
+{
+ wmb();
+ return STORE_SHARED(p, v);
+}
+
+void *rcu_xchg_pointer_sym(void **p, void *v)
+{
+ wmb();
+ return xchg(p, v);
+}
+
+void *rcu_publish_content_sym(void **p, void *v)
+{
+ void *oldptr;
+
+ oldptr = _rcu_xchg_pointer(p, v);
+ synchronize_rcu();
+ return oldptr;
+}
+
+static void rcu_add_reader(pthread_t id)
{
struct reader_registry *oldarray;
* Never shrink (implementation limitation).
* This is O(nb threads). Eventually use a hash table.
*/
-void urcu_remove_reader(pthread_t id)
+static void rcu_remove_reader(pthread_t id)
{
struct reader_registry *index;
assert(0);
}
-void urcu_register_thread(void)
+void rcu_register_thread(void)
{
internal_urcu_lock();
- urcu_add_reader(pthread_self());
+ rcu_add_reader(pthread_self());
internal_urcu_unlock();
}
-void urcu_unregister_thread(void)
+void rcu_unregister_thread(void)
{
internal_urcu_lock();
- urcu_remove_reader(pthread_self());
+ rcu_remove_reader(pthread_self());
internal_urcu_unlock();
}
#ifndef DEBUG_FULL_MB
-void sigurcu_handler(int signo, siginfo_t *siginfo, void *context)
+static void sigurcu_handler(int signo, siginfo_t *siginfo, void *context)
{
/*
* Executing this smp_mb() is the only purpose of this signal handler.
assert(act.sa_sigaction == sigurcu_handler);
free(registry);
}
-#endif
+#endif /* #ifndef DEBUG_FULL_MB */
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