From 779629ad3321b84fc8fad7d2d9b4561a8a99753e Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <seth@kipro-pcb.com>
Date: Sun, 12 Dec 2021 07:19:56 -0800
Subject: [PATCH] Fix deadlock

Fixes https://gitlab.com/kicad/code/kicad/issues/9959
---
 pcbnew/connectivity/connectivity_data.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/pcbnew/connectivity/connectivity_data.cpp b/pcbnew/connectivity/connectivity_data.cpp
index 6d516e3ac3..764c3c5c0e 100644
--- a/pcbnew/connectivity/connectivity_data.cpp
+++ b/pcbnew/connectivity/connectivity_data.cpp
@@ -85,7 +85,10 @@ bool CONNECTIVITY_DATA::Update( BOARD_ITEM* aItem )
 
 void CONNECTIVITY_DATA::Build( BOARD* aBoard, PROGRESS_REPORTER* aReporter )
 {
-    std::unique_lock<KISPINLOCK> lock( m_lock );
+    std::unique_lock<KISPINLOCK> lock( m_lock, std::try_to_lock );
+
+    if( !lock )
+        return;
 
     m_connAlgo.reset( new CN_CONNECTIVITY_ALGO );
     m_connAlgo->Build( aBoard, aReporter );
@@ -102,7 +105,10 @@ void CONNECTIVITY_DATA::Build( BOARD* aBoard, PROGRESS_REPORTER* aReporter )
 
 void CONNECTIVITY_DATA::Build( const std::vector<BOARD_ITEM*>& aItems )
 {
-    std::unique_lock<KISPINLOCK> lock( m_lock );
+    std::unique_lock<KISPINLOCK> lock( m_lock, std::try_to_lock );
+
+    if( !lock )
+        return;
 
     m_connAlgo.reset( new CN_CONNECTIVITY_ALGO );
     m_connAlgo->Build( aItems );