From 142b38baca73d5c0bf5e11f6f7789e60cf7da041 Mon Sep 17 00:00:00 2001
From: Colin Dellow <cldellow@gmail.com>
Date: Mon, 23 Sep 2024 04:36:22 -0400
Subject: [PATCH] thread-safety fixes: PooledString, layer metadata (#761)

---
 src/osm_lua_processing.cpp | 3 +++
 src/pooled_string.cpp      | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/osm_lua_processing.cpp b/src/osm_lua_processing.cpp
index 545b1f37..76201ebd 100644
--- a/src/osm_lua_processing.cpp
+++ b/src/osm_lua_processing.cpp
@@ -17,6 +17,8 @@ const std::string EMPTY_STRING = "";
 thread_local kaguya::State *g_luaState = nullptr;
 thread_local OsmLuaProcessing* osmLuaProcessing = nullptr;
 
+std::mutex vectorLayerMetadataMutex;
+
 void handleOsmLuaProcessingUserSignal(int signum) {
 	osmLuaProcessing->handleUserSignal(signum);
 }
@@ -913,6 +915,7 @@ std::string OsmLuaProcessing::FindInRelation(const std::string &key) {
 
 // Record attribute name/type for vector_layers table
 void OsmLuaProcessing::setVectorLayerMetadata(const uint_least8_t layer, const string &key, const uint type) {
+	std::lock_guard<std::mutex> lock(vectorLayerMetadataMutex);
 	layers.layers[layer].attributeMap[key] = type;
 }
 
diff --git a/src/pooled_string.cpp b/src/pooled_string.cpp
index a7aea1cf..393e9f9b 100644
--- a/src/pooled_string.cpp
+++ b/src/pooled_string.cpp
@@ -2,9 +2,10 @@
 #include <stdexcept>
 #include <mutex>
 #include <cstring>
+#include <deque>
 
 namespace PooledStringNS {
-	std::vector<char*> tables;
+	std::deque<char*> tables;
 	std::mutex mutex;
 
 	const uint8_t ShortString = 0b00;