Fix a bug in sp<> and wp<> which could cause memory corruptions
when assigning a smart pointer to another one, we need to make
sure to read all the data we need from the right-hand-side
reference (the assignee) before we decRef the assigned.
This bug would cause linked-list of smart-pointers to fail
miserably.
Change-Id: Ibb554c15fddf909f7737c632b7c80322e80ea93f
diff --git a/include/utils/RefBase.h b/include/utils/RefBase.h
index bd7f28c..9c64ac0 100644
--- a/include/utils/RefBase.h
+++ b/include/utils/RefBase.h
@@ -333,9 +333,10 @@
template<typename T>
sp<T>& sp<T>::operator = (const sp<T>& other) {
- if (other.m_ptr) other.m_ptr->incStrong(this);
+ T* otherPtr(other.m_ptr);
+ if (otherPtr) otherPtr->incStrong(this);
if (m_ptr) m_ptr->decStrong(this);
- m_ptr = other.m_ptr;
+ m_ptr = otherPtr;
return *this;
}
@@ -351,9 +352,10 @@
template<typename T> template<typename U>
sp<T>& sp<T>::operator = (const sp<U>& other)
{
- if (other.m_ptr) other.m_ptr->incStrong(this);
+ U* otherPtr(other.m_ptr);
+ if (otherPtr) otherPtr->incStrong(this);
if (m_ptr) m_ptr->decStrong(this);
- m_ptr = other.m_ptr;
+ m_ptr = otherPtr;
return *this;
}
@@ -466,10 +468,12 @@
template<typename T>
wp<T>& wp<T>::operator = (const wp<T>& other)
{
- if (other.m_ptr) other.m_refs->incWeak(this);
+ weakref_type* otherRefs(other.m_refs);
+ T* otherPtr(other.m_ptr);
+ if (otherPtr) otherRefs->incWeak(this);
if (m_ptr) m_refs->decWeak(this);
- m_ptr = other.m_ptr;
- m_refs = other.m_refs;
+ m_ptr = otherPtr;
+ m_refs = otherRefs;
return *this;
}
@@ -478,8 +482,9 @@
{
weakref_type* newRefs =
other != NULL ? other->createWeak(this) : 0;
+ T* otherPtr(other.m_ptr);
if (m_ptr) m_refs->decWeak(this);
- m_ptr = other.get();
+ m_ptr = otherPtr;
m_refs = newRefs;
return *this;
}
@@ -498,10 +503,12 @@
template<typename T> template<typename U>
wp<T>& wp<T>::operator = (const wp<U>& other)
{
- if (other.m_ptr) other.m_refs->incWeak(this);
+ weakref_type* otherRefs(other.m_refs);
+ U* otherPtr(other.m_ptr);
+ if (otherPtr) otherRefs->incWeak(this);
if (m_ptr) m_refs->decWeak(this);
- m_ptr = other.m_ptr;
- m_refs = other.m_refs;
+ m_ptr = otherPtr;
+ m_refs = otherRefs;
return *this;
}
@@ -510,8 +517,9 @@
{
weakref_type* newRefs =
other != NULL ? other->createWeak(this) : 0;
+ U* otherPtr(other.m_ptr);
if (m_ptr) m_refs->decWeak(this);
- m_ptr = other.get();
+ m_ptr = otherPtr;
m_refs = newRefs;
return *this;
}