summaryrefslogtreecommitdiffstats
path: root/Source/JavaScriptCore/wtf/RefCounted.h
diff options
context:
space:
mode:
Diffstat (limited to 'Source/JavaScriptCore/wtf/RefCounted.h')
-rw-r--r--Source/JavaScriptCore/wtf/RefCounted.h169
1 files changed, 169 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/wtf/RefCounted.h b/Source/JavaScriptCore/wtf/RefCounted.h
new file mode 100644
index 0000000..8d8b302
--- /dev/null
+++ b/Source/JavaScriptCore/wtf/RefCounted.h
@@ -0,0 +1,169 @@
+/*
+ * Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef RefCounted_h
+#define RefCounted_h
+
+#include "Assertions.h"
+#include "Noncopyable.h"
+
+namespace WTF {
+
+// This base class holds the non-template methods and attributes.
+// The RefCounted class inherits from it reducing the template bloat
+// generated by the compiler (technique called template hoisting).
+class RefCountedBase {
+public:
+ void ref()
+ {
+ ASSERT(!m_deletionHasBegun);
+ ASSERT(!m_adoptionIsRequired);
+ ++m_refCount;
+ }
+
+ bool hasOneRef() const
+ {
+ ASSERT(!m_deletionHasBegun);
+ return m_refCount == 1;
+ }
+
+ int refCount() const
+ {
+ return m_refCount;
+ }
+
+ void relaxAdoptionRequirement()
+ {
+#ifndef NDEBUG
+ ASSERT(!m_deletionHasBegun);
+ ASSERT(m_adoptionIsRequired);
+ m_adoptionIsRequired = false;
+#endif
+ }
+
+protected:
+ RefCountedBase()
+ : m_refCount(1)
+#ifndef NDEBUG
+ , m_deletionHasBegun(false)
+ , m_adoptionIsRequired(true)
+#endif
+ {
+ }
+
+ ~RefCountedBase()
+ {
+ ASSERT(m_deletionHasBegun);
+ ASSERT(!m_adoptionIsRequired);
+ }
+
+ // Returns whether the pointer should be freed or not.
+ bool derefBase()
+ {
+ ASSERT(!m_deletionHasBegun);
+ ASSERT(!m_adoptionIsRequired);
+
+ ASSERT(m_refCount > 0);
+ if (m_refCount == 1) {
+#ifndef NDEBUG
+ m_deletionHasBegun = true;
+#endif
+ return true;
+ }
+
+ --m_refCount;
+ return false;
+ }
+
+ // Helper for generating JIT code. Please do not use for non-JIT purposes.
+ int* addressOfCount()
+ {
+ return &m_refCount;
+ }
+
+#ifndef NDEBUG
+ bool deletionHasBegun() const
+ {
+ return m_deletionHasBegun;
+ }
+#endif
+
+private:
+ template<typename T> friend class CrossThreadRefCounted;
+
+#ifndef NDEBUG
+ friend void adopted(RefCountedBase*);
+#endif
+
+ int m_refCount;
+#ifndef NDEBUG
+ bool m_deletionHasBegun;
+ bool m_adoptionIsRequired;
+#endif
+};
+
+#ifndef NDEBUG
+
+inline void adopted(RefCountedBase* object)
+{
+ if (!object)
+ return;
+ ASSERT(!object->m_deletionHasBegun);
+ object->m_adoptionIsRequired = false;
+}
+
+#endif
+
+template<typename T> class RefCounted : public RefCountedBase, public Noncopyable {
+public:
+ void deref()
+ {
+ if (derefBase())
+ delete static_cast<T*>(this);
+ }
+
+protected:
+ ~RefCounted()
+ {
+ }
+};
+
+template<typename T> class RefCountedCustomAllocated : public RefCountedBase {
+ WTF_MAKE_NONCOPYABLE(RefCountedCustomAllocated);
+
+public:
+ void deref()
+ {
+ if (derefBase())
+ delete static_cast<T*>(this);
+ }
+
+protected:
+ ~RefCountedCustomAllocated()
+ {
+ }
+};
+
+} // namespace WTF
+
+using WTF::RefCounted;
+using WTF::RefCountedCustomAllocated;
+
+#endif // RefCounted_h