[master] 89705bd Warn about global state in VMODs

[Dridi Boukelmoune]

commit 89705bd2b1be138d002bb5dd56f9a35597f9efbd
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Mon Mar 13 14:25:05 2017 +0100

    Warn about global state in VMODs

diff --git a/doc/sphinx/whats-new/changes-5.1.rst b/doc/sphinx/whats-new/changes-5.1.rst
index 25cedbe..a0c2297 100644
--- a/doc/sphinx/whats-new/changes-5.1.rst
+++ b/doc/sphinx/whats-new/changes-5.1.rst
@@ -291,5 +291,10 @@ News for authors of VMODs and Varnish API client applications
   name inside the workdir, from which the running VCL access it.  This
   ensures that Varnishd can always restart the worker process, no matter
   what happened to the original VMOD file.
+
+  It also means that VMODs maintaining state spanning VCL reloads might
+  break. It is still possible to maintain global state in a VMOD despite
+  VMOD caching: one solution is to move the global state into separate
+  shared library that won't be cached by Varnish.
  
 *EOF*