From 86a887d7b09358cb6a535b001aff7a8cfc73d781 Mon Sep 17 00:00:00 2001
From: Silent <zdanio95@gmail.com>
Date: Sat, 10 Aug 2019 20:55:52 +0200
Subject: [PATCH] Init GlobalThreadPool in a thread safe manner

---
 Common/ThreadPools.cpp | 12 +++++-------
 Common/ThreadPools.h   |  4 ++--
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/Common/ThreadPools.cpp b/Common/ThreadPools.cpp
index 53bfe12dfa..9af420cf37 100644
--- a/Common/ThreadPools.cpp
+++ b/Common/ThreadPools.cpp
@@ -1,18 +1,16 @@
 #include "ThreadPools.h"
 
 #include "../Core/Config.h"
+#include "Common/MakeUnique.h"
 
-std::shared_ptr<ThreadPool> GlobalThreadPool::pool;
-bool  GlobalThreadPool::initialized = false;
+std::unique_ptr<ThreadPool> GlobalThreadPool::pool;
+std::once_flag GlobalThreadPool::init_flag;
 
 void GlobalThreadPool::Loop(const std::function<void(int,int)>& loop, int lower, int upper) {
-	Inititialize();
+	std::call_once(init_flag, Inititialize);
 	pool->ParallelLoop(loop, lower, upper);
 }
 
 void GlobalThreadPool::Inititialize() {
-	if(!initialized) {
-		pool = std::make_shared<ThreadPool>(g_Config.iNumWorkerThreads);
-		initialized = true;
-	}
+	pool = make_unique<ThreadPool>(g_Config.iNumWorkerThreads);
 }
diff --git a/Common/ThreadPools.h b/Common/ThreadPools.h
index 2ae46c2c00..e04303a9d2 100644
--- a/Common/ThreadPools.h
+++ b/Common/ThreadPools.h
@@ -9,7 +9,7 @@ public:
 	static void Loop(const std::function<void(int,int)>& loop, int lower, int upper);
 
 private:
-	static std::shared_ptr<ThreadPool> pool;
-	static bool initialized;
+	static std::unique_ptr<ThreadPool> pool;
+	static std::once_flag init_flag;
 	static void Inititialize();
 };