lwipClient - fix mem pool leak

[JAndrassy]

fix mem pool leak in lwipClient with shared_ptr with custom deleter.
for lwipClient created from lwipServer the deleter doesn't free the struct. server releases the clients it manages. it would be better if the server used an array of lwipClient objects. then the shared_ptr in them would hold the pointer. maybe in a follow up PR if this is merged.

[aentinger]

I'm not seeing it. Sure using a std::shared_ptr would be a pretty clean solution, but you could always just call delete (or mem_free) in the Destructor. Having a mem_alloc (a C function) inside of reset (a member of a C++ template class) just feels super weird. What do you think?

[JAndrassy]

you could always just call delete (or mem_free) in the Destructor.

no. Client must be copyable. multiple copies of Client can point to the same TCP connection

having a mem_alloc (a C function) inside of reset (a member of a C++ template class) just feels super weird

not really. the resetfunction is just a assignment which allows to specify a deleter. uses of shared_ptr should be written as close as possible as with a basic pointer

[aentinger]

Client must be copyable

Overload copy-ctor. But yeah, I do see your point somewhat. Can you prepare a adjacent PR showing how you'd like to take this further?

[JAndrassy]

Can you prepare a adjacent PR showing how you'd like to take this further?

ok

[andreagilardoni]

This issue depends on arduino/ArduinoCore-API#218

[JAndrassy]

This issue depends on arduino/ArduinoCore-API#218

no. tcp_client is not a class
and WiFiClient is never deleted from LwipClent pointer and it even doesn't make sense to do new for WiFiClient. that is why Arduino is not really missing the virtual destructor.