From 765f3eadad5647e6fa853414fc652670f9e00966 Mon Sep 17 00:00:00 2001
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Sat, 10 Sep 2011 22:02:58 -0700
Subject: [PATCH] call_rcu: register work threads as rcu readers

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 urcu-bp.h            | 15 +++++++++++++++
 urcu-call-rcu-impl.h |  8 ++++++++
 urcu.h               | 15 +++++++++++++++
 3 files changed, 38 insertions(+)

diff --git a/urcu-bp.h b/urcu-bp.h
index 09ee9c9..451bedb 100644
--- a/urcu-bp.h
+++ b/urcu-bp.h
@@ -114,6 +114,21 @@ static inline void rcu_init(void)
 {
 }
 
+/*
+ * Q.S. reporting are no-ops for these URCU flavors.
+ */
+static inline void rcu_quiescent_state(void)
+{
+}
+
+static inline void rcu_thread_offline(void)
+{
+}
+
+static inline void rcu_thread_online(void)
+{
+}
+
 #ifdef __cplusplus 
 }
 #endif
diff --git a/urcu-call-rcu-impl.h b/urcu-call-rcu-impl.h
index b9e57cd..38cc001 100644
--- a/urcu-call-rcu-impl.h
+++ b/urcu-call-rcu-impl.h
@@ -215,6 +215,11 @@ static void *call_rcu_thread(void *arg)
 		exit(-1);
 	}
 
+	/*
+	 * If callbacks take a read-side lock, we need to be registered.
+	 */
+	rcu_register_thread();
+
 	thread_call_rcu_data = crdp;
 	if (!rt) {
 		uatomic_dec(&crdp->futex);
@@ -247,6 +252,7 @@ static void *call_rcu_thread(void *arg)
 		}
 		if (uatomic_read(&crdp->flags) & URCU_CALL_RCU_STOP)
 			break;
+		rcu_thread_offline();
 		if (!rt) {
 			if (&crdp->cbs.head
 			    == _CMM_LOAD_SHARED(crdp->cbs.tail)) {
@@ -264,6 +270,7 @@ static void *call_rcu_thread(void *arg)
 		} else {
 			poll(NULL, 0, 10);
 		}
+		rcu_thread_online();
 	}
 	if (!rt) {
 		/*
@@ -273,6 +280,7 @@ static void *call_rcu_thread(void *arg)
 		uatomic_set(&crdp->futex, 0);
 	}
 	uatomic_or(&crdp->flags, URCU_CALL_RCU_STOPPED);
+	rcu_unregister_thread();
 	return NULL;
 }
 
diff --git a/urcu.h b/urcu.h
index 5728c07..1ad971c 100644
--- a/urcu.h
+++ b/urcu.h
@@ -107,6 +107,21 @@ extern void rcu_unregister_thread(void);
  */
 extern void rcu_init(void);
 
+/*
+ * Q.S. reporting are no-ops for these URCU flavors.
+ */
+static inline void rcu_quiescent_state(void)
+{
+}
+
+static inline void rcu_thread_offline(void)
+{
+}
+
+static inline void rcu_thread_online(void)
+{
+}
+
 #ifdef __cplusplus 
 }
 #endif
-- 
2.34.1