X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu.c;h=8fd6195662d33a996467fe78a065cacf7d739b01;hp=38abf7d6a92e045bb2aabbc306a4b7006ed108f8;hb=5e13fab888d07ba3657ac9e1eb0441450ea17837;hpb=09a9f9867bf0c7fd793f46f1e639ad2042175721

diff --git a/urcu.c b/urcu.c
index 38abf7d..8fd6195 100644
--- a/urcu.c
+++ b/urcu.c
@@ -3,9 +3,24 @@
  *
  * 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>
@@ -15,7 +30,10 @@
 #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;
@@ -99,17 +117,19 @@ static void switch_next_urcu_qparity(void)
 }
 
 #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);
@@ -132,6 +152,7 @@ static void force_mb_single_thread(struct reader_registry *index)
 	}
 	smp_mb();	/* read ->need_mb before ending the barrier */
 }
+#endif /* #ifdef HAS_INCOHERENT_CACHES */
 
 static void force_mb_all_threads(void)
 {
@@ -174,7 +195,7 @@ 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)
 {
@@ -186,6 +207,10 @@ 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
@@ -199,6 +224,7 @@ void wait_for_quiescent_state(void)
 				cpu_relax();
 			}
 		}
+#endif /* #else #ifndef HAS_INCOHERENT_CACHES */
 	}
 }
 
@@ -258,7 +284,47 @@ void synchronize_rcu(void)
 	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;
 
@@ -288,7 +354,7 @@ void urcu_add_reader(pthread_t id)
  * 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;
 
@@ -307,22 +373,22 @@ void urcu_remove_reader(pthread_t id)
 	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.
@@ -360,4 +426,4 @@ void __attribute__((destructor)) urcu_exit(void)
 	assert(act.sa_sigaction == sigurcu_handler);
 	free(registry);
 }
-#endif
+#endif /* #ifndef DEBUG_FULL_MB */