Re: [boost] Could shared_ptr cause memory leak?

Thanks Josh, just wandering why the shared_ptr does not have a dereference function? Looks the only way to break the reference loop manually is calling b.reset() which might cause other implication, I am going to use a raw pointer. Never use shared_from_this to its own members. On 1/4/19, Josh Juran via Boost wrote:

On Jan 3, 2019, at 2:25 PM, hh h via Boost wrote:

...

Suppose I have a session object A, the shared_ptr<A> is created and stored in a global connection list after a connection is accepted by async_accept, when the connection is terminated, the reference in connection list is removed, but since A has a member B still holds A reference, that session object is never deleted, is it memory leak?

class A : public boost::enable_shared_from_this<A> { public: A(); ~A(); void Start() {b = make_shared<B>(shared_from_this());} void Stop(); private: shared_ptr<B> b; };

Yes, what you describe is a resource leak due to a reference loop foiling shared_ptr's RAII reference counting.

There are several ways to remedy this, one of which is to use a weak_ptr for one of the references. Higher-risk options include making sure to break the reference loop manually, or using a raw pointer instead.

Josh

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