TLM Extensions - memory deallocation and clone() and copy_from() functions

[RBN]

Hello,

  I am new to TLM and I am looking to implement a model that will be using b_transport() calls with tlm_generic_payload and a custom extension. If we allocate the custom extension objects from the heap, when/where can I safely deallocate the custom extension object?

  Also, while defining the custom extensions, we have to implement clone() and copy_from() functions (inherited form tlm_extension_base). I want to know when do these functions called? In the TLM extension examples I have seen, the clone() function definition includes a call to new() to allocate a new object. Is this clone deallocated (deleted) by the framework/library or is the user responsible for deallocating the clone? If we want to use a memory pool for the extension objects, how can we do that?

Thanks!

[Eyck]

tlm_extension handling is generally the responsibility of the user. The onyl exception here is if you use set_auto_extension(), in this case the extension is deallocated by the generic payload. But this is only to be used with a tlm_mm memory manager.

The same applies to the cloned extensions, clone is use in the deep_copy_from() function of the generic payload.

[RBN]

44 minutes ago, Eyck said:

tlm_extension handling is generally the responsibility of the user. The onyl exception here is if you use set_auto_extension(), in this case the extension is deallocated by the generic payload. But this is only to be used with a tlm_mm memory manager.

The same applies to the cloned extensions, clone is use in the deep_copy_from() function of the generic payload.

Got it. Thanks!

I just downloaded the Accellera SystemC library code after seeing your reply and looks like deep_copy_from() is not called from any code within the library, users can can use it to deep-copy from one payload object to another. So if I am using set_extension() then after the return from the b_transport(), I can deallocate (or return to the pool) the custom extension object.