Re: Improve LWLock tranche name visibility across backends

Hi,+
+                               copied_addr = dsa_get_address(LWLockTrancheNames.dsa, copied_ptr);
+                               memcpy(copied_addr, old_name, len);
+
+                               new_ptrs[i] = copied_ptr;
+
+                               /* free old tranche names */
+                               dsa_free(LWLockTrancheNames.dsa, old_ptrs[i]);

Why is it necessary to allocate a new dsa_pointer for tranche names that are the same size and then
free the old one?
Is there a reason we can't just assign new_ptrs[i] = old_ptrs[i]?

3. 
>Additionally, while users should not pass arbitrary tranche IDs (that is,
>IDs not created via LWLockNewTrancheId) to LWLockInitialize, nothing
>technically prevents them from doing so. Therefore, we must continue to
>handle such cases gracefully by returning a default "extension" tranche name.

Would it be possible to update LWLockInitialize so that it checks if tranche_id is
already registered in the dsa, and if not, registers it during the LWLockInitialize() process?  

Thank you,