From 76cb1fcf0b5b9d8415e2517c482bab0c6c6602fb Mon Sep 17 00:00:00 2001
From: Nat Goodspeed <nat@lindenlab.com>
Date: Mon, 29 Jun 2015 15:37:32 -0400
Subject: MAINT-4952: Add IntrusivePtr wrapper for boost::intrusive_ptr. For a
 RefCounted subclass T, boost::intrusive_ptr<T> must be instantiated as
 boost::intrusive_ptr<T>(raw ptr, false) to avoid immortal instances.
 Forgetting that final bool parameter is both easy and extremely hard to spot
 with desk checking or code review. IntrusivePtr<T> provides constructors that
 Do The Right Thing, so we can typedef a subclass T's ptr_t to IntrusivePtr<T>
 rather than directly to boost::intrusive_ptr<T>.

---
 indra/llcorehttp/_refcounted.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

(limited to 'indra/llcorehttp')

diff --git a/indra/llcorehttp/_refcounted.h b/indra/llcorehttp/_refcounted.h
index cd16e2e2b4..7f713f2298 100755
--- a/indra/llcorehttp/_refcounted.h
+++ b/indra/llcorehttp/_refcounted.h
@@ -32,6 +32,7 @@
 
 #include "fix_macros.h"
 #include <boost/thread.hpp>
+#include <boost/intrusive_ptr.hpp>
 
 #include "llapr.h"
 
@@ -120,6 +121,24 @@ inline void RefCounted::destroySelf()
 	delete this;
 }
 
+/**
+ * boost::intrusive_ptr may be used to manage RefCounted classes.
+ * Unfortunately RefCounted and boost::intrusive_ptr use different conventions
+ * for the initial refcount value. To avoid leaky (immortal) objects, you
+ * should really construct boost::intrusive_ptr<RefCounted*>(rawptr, false).
+ * IntrusivePtr<T> encapsulates that for you.
+ */
+template <typename T>
+struct IntrusivePtr: public boost::intrusive_ptr<T>
+{
+	IntrusivePtr():
+		boost::intrusive_ptr<T>()
+	{}
+	IntrusivePtr(T* p):
+		boost::intrusive_ptr<T>(p, false)
+	{}
+};
+
 inline void intrusive_ptr_add_ref(RefCounted* p)
 {
 	p->addRef();
-- 
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