#5107: Block the changed signal until parsing is done. When the signa…

…l is fired, we must be ready to serve queries to entity classes or model defs without deadlocking in our own ongoing parsing thread.

The change signal is buffered, and should be fired once parsing is done.

libs/ThreadedDefLoader.h

@@ -49,7 +49,7 @@ class ThreadedDefLoader
         ensureLoaderStarted();
     }
 
-    // Ensrues that the worker thread has been started and is done processing
+    // Ensures that the worker thread has been started and is done processing
     // This will block and wait for the worker execution before returning to the caller.
     void ensureFinished()
     {

radiantcore/eclass/EClassManager.cpp

@@ -441,11 +441,18 @@ void EClassManager::parse(TextInputStream& inStr, const vfs::FileInfo& fileInfo,
 
 			i->second->setParseStamp(_curParseStamp);
 
+            // Hold back the changed signal for the moment being
+            i->second->blockChangedSignal(true);
+            // Add this eclass to the queue (we'll fire the signal when we're done parsing)
+            _changeNotificationQueue.emplace_back(*i->second);
+
         	// Parse the contents of the eclass (excluding name)
 			i->second->parseFromTokens(tokeniser);
 
 			// Set the mod directory
         	i->second->setModName(modDir);
+
+            i->second->blockChangedSignal(false);
         }
         else if (blockType == "model")
 		{

radiantcore/eclass/EClassManager.h

@@ -55,6 +55,11 @@ class EClassManager :
 
     sigc::connection _eclassColoursChanged;
 
+    // During reparsing, we block all eclass changed signals to avoid deadlocks
+    // This queue will contain all the eclasses that need to send out their updates
+    // which will be done immediately after parsing is done
+    std::vector<std::reference_wrapper<EntityClass>> _changeNotificationQueue;
+
 public:
     // Constructor
 	EClassManager();

radiantcore/eclass/EntityClass.cpp

@@ -31,10 +31,8 @@ EntityClass::EntityClass(const std::string& name, const vfs::FileInfo& fileInfo,
   _inheritanceResolved(false),
   _modName("base"),
   _emptyAttribute("", "", ""),
-  _parseStamp(0)
-{}
-
-EntityClass::~EntityClass()
+  _parseStamp(0),
+  _blockChangeSignal(false)
 {}
 
 std::string EntityClass::getName() const
@@ -109,7 +107,7 @@ void EntityClass::setColour(const Vector3& colour)
 
     _wireShader = fmt::format("<{0:f} {1:f} {2:f}>", _colour[0], _colour[1], _colour[2]);
 
-    _changedSignal.emit();
+    emitChangedSignal();
 }
 
 void EntityClass::resetColour()
@@ -456,7 +454,7 @@ void EntityClass::parseFromTokens(parser::DefTokeniser& tokeniser)
     } // while true
 
     // Notify the observers
-    _changedSignal.emit();
+    emitChangedSignal();
 }
 
 } // namespace eclass

radiantcore/eclass/EntityClass.h

@@ -86,6 +86,7 @@ class EntityClass
 
     // Emitted when contents are reloaded
     sigc::signal<void> _changedSignal;
+    bool _blockChangeSignal;
 
 private:
     // Clear all contents (done before parsing from tokens)
@@ -131,8 +132,6 @@ class EntityClass
      */
     EntityClass(const std::string& name, const vfs::FileInfo& fileInfo, bool fixedSize);
 
-    virtual ~EntityClass();
-
     /// Add a new attribute
     void addAttribute(const EntityClassAttribute& attribute);
 
@@ -209,6 +208,19 @@ class EntityClass
     {
         return _parseStamp;
     }
+
+    void emitChangedSignal()
+    {
+        if (!_blockChangeSignal)
+        {
+            _changedSignal.emit();
+        }
+    }
+
+    void blockChangedSignal(bool block)
+    {
+        _blockChangeSignal = block;
+    }
 };
 
 }