Rename xpcc "SmartPointer"

[ekiwi]

So I just stumbled upon the xpcc xpcc::SmartPointer which confused me for a while, until I had a look at the implementation. While it might not have been the case in 2009, currently a smart pointer is a pretty specific concept used in the c++ standard library.
I just assumed, that a xpcc::SmartPointer would act the same as the std::shared_ptr which it does not. I figured that out after searching for the point at which memory to be managed by the xpcc::SmartPointer was allocated. This point does not exist, as the xpcc::SmartPointer exclusively manages a runtime sized uint8_t array which it allocates internally.
Thus it makes sense to keep the xpcc::SmartPointer implementation in the container directory.

The naming however is imho very misleading.

I therefore propose the rename xpcc::SmartPointer. I haven't come up with a good enough name yet, but some possibilities are:

• xpcc::SharedMemory
• xpcc::ManagedMemory
• xpcc::ManagedSharedMemory

Does anyone have a better suggestion, or does anyone oppose a name change?

[salkinium]

+1. I was also extremely confused by the naming of this thing, and I very much dislike its internal implementation.
std::shared_ptr alongside std::make_shared are the only acceptable smart pointer for wide use.
Of course, we would have to port it to AVR, since we currently have no Standard Library (also see #20).

If I recall correctly, the xpcc::SmartPointer is not templated for a type, so that it can be passed to the xpcc::Dispatcher. It was meant as an internal XPCC mechanism to keep track of memory, and is not meant for wider use in the framework.

I like the name xpcc::SharedMemory.

[mredd]

Am 30.09.2015 um 20:34 schrieb Kevin Laeufer [email protected]:
I therefore propose the rename xpcc::SmartPointer. I haven't come up with a good enough name yet, but some possibilities are:

xpcc::SharedMemory
xpcc::ManagedMemory
xpcc::ManagedSharedMemory
Does anyone have a better suggestion, or does anyone oppose a name change?

I haven't had a Look into the exact implementation, but the concept you described reminds on what boost is calling scoped_array<uint8_t> for many, many years.

http://www.boost.org/doc/libs/1_59_0/libs/smart_ptr/scoped_array.htm

If the xpcc implementation features reference counting, you probably want to call it shared_array.

Regards,
Christoph

[salkinium]

Oh and btw: xpcc::SmartPointer can actually be defined as a builtin type for XPCC communication!

<builtin name="xpcc::SmartPointer" size="4" />
<typedef name="Data Pointer" type="xpcc::SmartPointer"/>

(size must be 2 for AVRs).
The support for that was secretly enabled by me in the innocent looking commit 6f2dfa9 ;-)

This was a hack to allow internal sharing of large amounts of memory (of variable length!) safely without copying it.
This obviously only works for a local event loop, something that isn't currently supported very well, but can be implemented using an empty implementation of xpcc::BackendInterface.