RefCounted.h

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#pragma once
 
#include <aws/common/assert.h>
#include <memory>
#include <mutex>
 
namespace Aws
{
    namespace Crt
    {
        template <class T> class RefCounted
        {
          protected:
            RefCounted() {}
            ~RefCounted() {}
 
            void AcquireRef()
            {
                m_mutex.lock();
                if (m_count++ == 0)
                {
                    m_strongPtr = static_cast<T *>(this)->shared_from_this();
                }
                m_mutex.unlock();
            }
 
            void ReleaseRef()
            {
                // Move contents of m_strongPtr to a temp so that this
                // object can't be destroyed until the function exits.
                std::shared_ptr<T> tmpStrongPtr;
 
                m_mutex.lock();
                AWS_ASSERT(m_count > 0 && "refcount has gone negative");
                if (m_count-- == 1)
                {
                    std::swap(m_strongPtr, tmpStrongPtr);
                }
                m_mutex.unlock();
            }
 
          private:
            RefCounted(const RefCounted &) = delete;
            RefCounted &operator=(const RefCounted &) = delete;
 
            size_t m_count = 0;
            std::shared_ptr<T> m_strongPtr;
            std::mutex m_mutex;
        };
    } // namespace Crt
} // namespace Aws