Experimental Physics and
Industrial Control System

Freddie Akeroyd via Core-talk <core-talk at aps.anl.gov> · Tue, 19 May 2020 23:08:04 -0000

The thread it is waiting on seems to be stuck in "common_end_thread" in
ucrtbase, calling ca_context_destroy() from main() with no DLL involved
works correctly.

There are various guidelines on what you should and should not do from inside a dllMain() function      
https://docs.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-best-practices
Unfortunately using a file level static class does not help as the same rules would appear to apply

"If your DLL is linked with the C run-time library (CRT), the entry
point provided by the CRT calls the constructors and destructors for
global and static C++ objects. Therefore, these restrictions for DllMain
also apply to constructors and destructors and any code that is called
from them."

(from https://docs.microsoft.com/en-us/windows/win32/dlls/dllmain )

-- 
You received this bug notification because you are a member of EPICS
Core Developers, which is subscribed to EPICS Base.
Matching subscriptions: epics-core-list-subscription
https://bugs.launchpad.net/bugs/1879532

Title:
  Can't completely shutdown libCa and libCom

Status in EPICS Base:
  Confirmed

Bug description:
  Most recently, Carsten Winkler reported in https://epics.anl.gov/tech-
  talk/2020/msg00946.php

      For a project I need to load and unload the Channel Access context in a
      shared library. Loading is no problem but unloading. It always fails
      during ca_context_destroy() function.

  This problem has been reported and discussed previously, see
  https://epics.anl.gov/tech-talk/2017/msg00371.php and
  https://epics.anl.gov/tech-talk/2004/msg00743.php thus it is a known
  issue which would probably require significant work to fix.

  This bug report is a place-holder for any work towards making it
  possible to completely shut down all libCom background threads and
  releasing the resources allocated by those subsystems.

To manage notifications about this bug go to:
https://bugs.launchpad.net/epics-base/+bug/1879532/+subscriptions

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System