From f3db64af0579628bc406e7a8c2fe3453b96360f6 Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Sun, 16 Apr 2023 15:35:58 +0100
Subject: [PATCH] Multi-threading safety.

(Possible fix for KICAD-74.)

(cherry picked from commit b76ef8c7e2bed4b6e11f0f38c28d42f340fcf8f5)
---
 pcbnew/connectivity/connectivity_data.cpp | 10 +++++++++-
 pcbnew/ratsnest/ratsnest_data.cpp         | 10 +---------
 pcbnew/ratsnest/ratsnest_data.h           | 13 +++++++++----
 3 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/pcbnew/connectivity/connectivity_data.cpp b/pcbnew/connectivity/connectivity_data.cpp
index 5c623ad7e9..fa5d4fb8b7 100644
--- a/pcbnew/connectivity/connectivity_data.cpp
+++ b/pcbnew/connectivity/connectivity_data.cpp
@@ -182,13 +182,21 @@ void CONNECTIVITY_DATA::updateRatsnest()
     thread_pool& tp = GetKiCadThreadPool();
 
     tp.push_loop( dirty_nets.size(),
-            [&]( const int a, const int b)
+            [&]( const int a, const int b )
             {
                 for( int ii = a; ii < b; ++ii )
                     dirty_nets[ii]->UpdateNet();
             } );
     tp.wait_for_tasks();
 
+    tp.push_loop( dirty_nets.size(),
+            [&]( const int a, const int b )
+            {
+                for( int ii = a; ii < b; ++ii )
+                    dirty_nets[ii]->OptimizeRNEdges();
+            } );
+    tp.wait_for_tasks();
+
 #ifdef PROFILE
     rnUpdate.Show();
 #endif
diff --git a/pcbnew/ratsnest/ratsnest_data.cpp b/pcbnew/ratsnest/ratsnest_data.cpp
index f7035fa452..bad7b70272 100644
--- a/pcbnew/ratsnest/ratsnest_data.cpp
+++ b/pcbnew/ratsnest/ratsnest_data.cpp
@@ -328,7 +328,7 @@ void RN_NET::compute()
 }
 
 
-void RN_NET::optimizeRNEdges()
+void RN_NET::OptimizeRNEdges()
 {
     auto optimizeZoneAnchor =
             [&]( const VECTOR2I& aPos, const LSET& aLayerSet,
@@ -448,14 +448,6 @@ void RN_NET::UpdateNet()
 {
     compute();
 
-#ifdef PROFILE
-    PROF_TIMER cnt( "optimize" );
-#endif
-    optimizeRNEdges();
-#ifdef PROFILE
-    cnt.Show();
-#endif
-
     m_dirty = false;
 }
 
diff --git a/pcbnew/ratsnest/ratsnest_data.h b/pcbnew/ratsnest/ratsnest_data.h
index f1d339bdf0..3553e3909f 100644
--- a/pcbnew/ratsnest/ratsnest_data.h
+++ b/pcbnew/ratsnest/ratsnest_data.h
@@ -76,6 +76,15 @@ public:
      * Recompute ratsnest for a net.
      */
     void UpdateNet();
+
+    /**
+     * Find optimal ends of RNEdges.  The MST will have found the closest anchors, but when
+     * zones are involved we might have points closer than the anchors.
+     *
+     * Normally called after UpdateNet(), but from a separate multi-threaded loop for safety.
+     */
+    void OptimizeRNEdges();
+
     void Clear();
 
     void AddCluster( std::shared_ptr<CN_CLUSTER> aCluster );
@@ -94,10 +103,6 @@ protected:
     ///< Compute the minimum spanning tree using Kruskal's algorithm
     void kruskalMST( const std::vector<CN_EDGE> &aEdges );
 
-    ///< Find optimal ends of RNEdges.  The MST will have found the closest anchors, but when
-    ///< zones are involved we might have points closer than the anchors.
-    void optimizeRNEdges();
-
 protected:
     ///< Vector of nodes
     std::multiset<std::shared_ptr<CN_ANCHOR>, CN_PTR_CMP> m_nodes;