From 5a7c68e3c9e9cf3f888761e679beb3ba251bf68b Mon Sep 17 00:00:00 2001
From: Johan Wikman <johan.wikman@mariadb.com>
Date: Wed, 28 Aug 2019 15:59:45 +0300
Subject: [PATCH] MXS-2612 Ensure that destructor order does not matter

The new configuration system relieas upon static varibles being
used for declaring what arguments a particular module uses. To
ensure that the destruction order does not matter, we redundantly
store the needed data (the name).
---
 include/maxscale/config2.hh |  7 ++++---
 server/core/config2.cc      | 10 +++++++---
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/include/maxscale/config2.hh b/include/maxscale/config2.hh
index 80ff88793..1ce9690f6 100644
--- a/include/maxscale/config2.hh
+++ b/include/maxscale/config2.hh
@@ -883,7 +883,7 @@ private:
     friend Type;
 
     void insert(Type* pValue);
-    void remove(Type* pValue);
+    void remove(Type* pValue, const std::string& name);
 
 private:
     std::string          m_name;
@@ -946,8 +946,9 @@ protected:
     Type(Configuration* pConfiguration, const Param* pParam);
 
 private:
-    Configuration& m_configuration;
-    const Param&   m_param;
+    Configuration&    m_configuration;
+    const Param&      m_param;
+    const std::string m_name;
 };
 
 /**
diff --git a/server/core/config2.cc b/server/core/config2.cc
index 3f87c5576..be10700a7 100644
--- a/server/core/config2.cc
+++ b/server/core/config2.cc
@@ -381,11 +381,12 @@ void Configuration::insert(Type* pValue)
     m_values.insert(make_pair(pValue->parameter().name(), pValue));
 }
 
-void Configuration::remove(Type* pValue)
+void Configuration::remove(Type* pValue, const std::string& name)
 {
-    auto it = m_values.find(pValue->parameter().name());
+    auto it = m_values.find(name);
 
     mxb_assert(it != m_values.end());
+    mxb_assert(it->second == pValue);
     m_values.erase(it);
 }
 
@@ -405,13 +406,16 @@ size_t Configuration::size() const
 Type::Type(Configuration* pConfiguration, const config::Param* pParam)
     : m_configuration(*pConfiguration)
     , m_param(*pParam)
+    , m_name(pParam->name())
 {
+    // The name is copied, so that we have access to it in the destructor
+    // also in the case that Param happens to be destructed first.
     m_configuration.insert(this);
 }
 
 Type::~Type()
 {
-    m_configuration.remove(this);
+    m_configuration.remove(this, m_name);
 }
 
 const config::Param& Type::parameter() const