1 files changed, 121 insertions, 0 deletions
diff --git a/source/core/StarAtomicSharedPtr.hpp b/source/core/StarAtomicSharedPtr.hpp
new file mode 100644
index 0000000..e85ffd5
--- /dev/null
+++ b/source/core/StarAtomicSharedPtr.hpp
@@ -0,0 +1,121 @@
+#ifndef STAR_ATOMIC_SHARED_PTR_HPP
+#define STAR_ATOMIC_SHARED_PTR_HPP
+
+#include "StarThread.hpp"
+
+namespace Star {
+
+// Thread safe shared_ptr such that is is possible to safely access the
+// contents of the shared_ptr while other threads might be updating it.  Makes
+// it possible to safely do Read Copy Update.
+template <typename T>
+class AtomicSharedPtr {
+public:
+  typedef shared_ptr<T> SharedPtr;
+  typedef weak_ptr<T> WeakPtr;
+
+  AtomicSharedPtr();
+  AtomicSharedPtr(AtomicSharedPtr const& p);
+  AtomicSharedPtr(AtomicSharedPtr&& p);
+  AtomicSharedPtr(SharedPtr p);
+
+  SharedPtr load() const;
+  WeakPtr weak() const;
+  void store(SharedPtr p);
+  void reset();
+
+  explicit operator bool() const;
+  bool unique() const;
+
+  SharedPtr operator->() const;
+
+  AtomicSharedPtr& operator=(AtomicSharedPtr const& p);
+  AtomicSharedPtr& operator=(AtomicSharedPtr&& p);
+  AtomicSharedPtr& operator=(SharedPtr p);
+
+private:
+  SharedPtr m_ptr;
+  mutable SpinLock m_lock;
+};
+
+template <typename T>
+AtomicSharedPtr<T>::AtomicSharedPtr() {}
+
+template <typename T>
+AtomicSharedPtr<T>::AtomicSharedPtr(AtomicSharedPtr const& p)
+  : m_ptr(p.load()) {}
+
+template <typename T>
+AtomicSharedPtr<T>::AtomicSharedPtr(AtomicSharedPtr&& p)
+  : m_ptr(move(p.m_ptr)) {}
+
+template <typename T>
+AtomicSharedPtr<T>::AtomicSharedPtr(SharedPtr p)
+  : m_ptr(move(p)) {}
+
+template <typename T>
+auto AtomicSharedPtr<T>::load() const -> SharedPtr {
+  SpinLocker locker(m_lock);
+  return m_ptr;
+}
+
+template <typename T>
+auto AtomicSharedPtr<T>::weak() const -> WeakPtr {
+  SpinLocker locker(m_lock);
+  return WeakPtr(m_ptr);
+}
+
+template <typename T>
+void AtomicSharedPtr<T>::store(SharedPtr p) {
+  SpinLocker locker(m_lock);
+  m_ptr = move(p);
+}
+
+template <typename T>
+void AtomicSharedPtr<T>::reset() {
+  SpinLocker locker(m_lock);
+  m_ptr.reset();
+}
+
+template <typename T>
+AtomicSharedPtr<T>::operator bool() const {
+  SpinLocker locker(m_lock);
+  return (bool)m_ptr;
+}
+
+template <typename T>
+bool AtomicSharedPtr<T>::unique() const {
+  SpinLocker locker(m_lock);
+  return m_ptr.unique();
+}
+
+template <typename T>
+auto AtomicSharedPtr<T>::operator-> () const -> SharedPtr {
+  SpinLocker locker(m_lock);
+  return m_ptr;
+}
+
+template <typename T>
+AtomicSharedPtr<T>& AtomicSharedPtr<T>::operator=(AtomicSharedPtr const& p) {
+  SpinLocker locker(m_lock);
+  m_ptr = p.load();
+  return *this;
+}
+
+template <typename T>
+AtomicSharedPtr<T>& AtomicSharedPtr<T>::operator=(AtomicSharedPtr&& p) {
+  SpinLocker locker(m_lock);
+  m_ptr = move(p.m_ptr);
+  return *this;
+}
+
+template <typename T>
+AtomicSharedPtr<T>& AtomicSharedPtr<T>::operator=(SharedPtr p) {
+  SpinLocker locker(m_lock);
+  m_ptr = move(p);
+  return *this;
+}
+
+}
+
+#endif