From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 9 Jun 2011 14:15:28 +0000 (-0400)
Subject: urcu_ref: do error checking on urcu_ref_put
X-Git-Tag: v0.6.0~27
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=bf27322dfd077203b5f8a58548560158dccd8c60;p=userspace-rcu.git

urcu_ref: do error checking on urcu_ref_put

Underflow is what you really want to trap.  When you reach urcu_ref_get,
it is already too late.

[Edit: whitespaces -> tab cleanup]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/urcu/urcu_ref.h b/urcu/urcu_ref.h
index bce7116..75620d1 100644
--- a/urcu/urcu_ref.h
+++ b/urcu/urcu_ref.h
@@ -33,14 +33,15 @@ static inline void urcu_ref_init(struct urcu_ref *ref)
 
 static inline void urcu_ref_get(struct urcu_ref *ref)
 {
-	long res = uatomic_add_return(&ref->refcount, 1);
-	assert(res != 0);
+	uatomic_add(&ref->refcount, 1);
 }
 
 static inline void urcu_ref_put(struct urcu_ref *ref,
 				void (*release)(struct urcu_ref *))
 {
-	if (!uatomic_sub_return(&ref->refcount, 1))
+	long res = uatomic_sub_return(&ref->refcount, 1);
+	assert (res >= 0);
+	if (res == 0)
 		release(ref);
 }