Re: sample extension: how to beam created proc tolkens to unload procedure

On Tue, 10 Dec 2024 17:11:08 +0100
Harald Oehlmann <wortkarg3@yahoo.com> wrote:

Am 10.12.2024 um 16:13 schrieb Emiliano:

On Tue, 10 Dec 2024 10:35:46 +0100

Sample_Init:
struct CmdClientData *cmdClientDataPtr;
cmdClientDataPtr = ckalloc(sizeof(struct Sha1ClientData));

-------------------------------------------^
Shouldn't this be "struct CmdClientDataPtr"?

 
Yes, good catch
 

cmdClientDataPtr->sha1CmdTolken = Tcl_CreateObjCommand(
    interp, "sha1", (Tcl_ObjCmdProc *)Sha1_Cmd,
              sha1ClientDataPtr, Sha1_CmdDeleteProc);

---------------^
Shouldn't this be "cmdClientDataPtr"?

 
Well, I use a client data for the command "sha1ClientDataPtr" with the
command state, which is deleted by the command delete proc
"Sha1_CmdDeleteProc".
 
In addition, there is assoc data of the dll "cmdClientDataPtr" to keep
the command tokens for removal within the unload procedure.
 
Is this design sensible ?

Can't say without seeing the real code, but ...

* If you delete the command [sha1], either using [rename] or by deleting
  the current interpreter or namespace, you might want to unload the
  library as well, and free all allocated resources;
* If you [unload] the library, you might want to also delete the [sha1]
  command, and free all allocated resources.
* If you are using Tcl_{Get|Set}AssocData, you have to check the right
  time to use ckfree if both cleanup functions depends on clientdata
  to be valid. In this case, Tcl_Preserve/Tcl_Release and
  Tcl_EventuallyFree might be useful. Or maybe adding a flag in the
  clientdata structure to mark "This cleanup function was already been called".

 
THanks for all,
Harald

Regards
--
Emiliano