Tcl Source Code

This does not happen on tcl8.5.7.
Please see the attached testcase.

just start tclsh

% package require testPackage
% exit
And the crash occurs.

OK so you destructor gets called by dlclose(), hence by TclFinalizeLoad, which is very late in the Tcl_Finalize sequence, notably *after* TclFinalizeObjects.

Hence you shouldn't do any Tcl_Obj freeing, nor anything Tcl-oriented for that matter, in the destructor. Just do things that are related to (1) the outside side-effects  of your extensions (created files or shared memory segments mainly), and (2) optionally private mallocs, and only  if you want to use a vlagrind-like tool to hunt leaks. All the rest is guaranteed to be properly nuked by the normal finalization process.

Ok!
Basically the load library call loads the dll and that is all is required. The Test_Init is just a stub and does not do anything.
The Constructor is called as there are static members and the destructor will be called on unload of the dll.
I hope that is it.

Uh, what I don't see is the link between the Tcl/extension API (XXX_Init and XXX_unload) and your C++ class's constructor and destructor. Maybe a file is missing ? Otherwise, how do you ensure that the constructor is called by Test_Init and (more importantly) the destructor by Test_Unload ?

I am not good at it, but let me try!
1. You need to compile the cpp file into a dll and modify the pkgIndex.tcl file accordingly to load the package.
2. The tclsh was compiled without threads.

The Crash Happens in the destructor
  ~TclFileHandles() {
     Tcl_UnregisterChannel(0, chann);
     Tcl_FSDeleteFile(channFileName);
     Tcl_DecrRefCount(channFileName);
    if (fp) { // hack as mentioned above
      fclose(fp); unlink(fpFileName.c_str());
    }
  }
 on Tcl_DecrRefCount(channFileName);

In a debugger, I could track it down to TclFreeObj function call where this problem was manifesting itself.

If you want some other info do let me know!

Regards,

A bit of human-readable context would be appreciated.
Basically you need a specific behavior from an extension to crash.
Please summarize it.

File Added - 358788: tclCrash858.tgz