From 04df8ee55eb9a04783bc66c44d17ef36097e5a9b Mon Sep 17 00:00:00 2001
From: Greg Clayton <gclayton@apple.com>
Date: Fri, 26 Feb 2016 19:38:18 +0000
Subject: [PATCH] Make sure the Target, Process and Thread
 GetGlobalProperties() static methods are thread safe.

<rdar://problem/22595283>

llvm-svn: 262053
---
 lldb/source/Target/Process.cpp |  8 ++++++--
 lldb/source/Target/Target.cpp  | 10 ++++++----
 lldb/source/Target/Thread.cpp  |  8 ++++++--
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/lldb/source/Target/Process.cpp b/lldb/source/Target/Process.cpp
index 97951f4..4f4643d 100644
--- a/lldb/source/Target/Process.cpp
+++ b/lldb/source/Target/Process.cpp
@@ -9,6 +9,7 @@
 
 // C Includes
 // C++ Includes
+#include <mutex>
 // Other libraries and framework includes
 // Project includes
 #include "lldb/Target/Process.h"
@@ -832,8 +833,11 @@ const ProcessPropertiesSP &
 Process::GetGlobalProperties()
 {
     static ProcessPropertiesSP g_settings_sp;
-    if (!g_settings_sp)
-        g_settings_sp.reset (new ProcessProperties (NULL));
+    static std::once_flag g_once_flag;
+    std::call_once(g_once_flag,  []() {
+        if (!g_settings_sp)
+            g_settings_sp.reset (new ProcessProperties (NULL));
+    });
     return g_settings_sp;
 }
 
diff --git a/lldb/source/Target/Target.cpp b/lldb/source/Target/Target.cpp
index 7d3543c..9719457 100644
--- a/lldb/source/Target/Target.cpp
+++ b/lldb/source/Target/Target.cpp
@@ -9,6 +9,7 @@
 
 // C Includes
 // C++ Includes
+#include <mutex>
 // Other libraries and framework includes
 // Project includes
 #include "lldb/Target/Target.h"
@@ -2778,10 +2779,11 @@ const TargetPropertiesSP &
 Target::GetGlobalProperties()
 {
     static TargetPropertiesSP g_settings_sp;
-    if (!g_settings_sp)
-    {
-        g_settings_sp.reset(new TargetProperties(nullptr));
-    }
+    static std::once_flag g_once_flag;
+    std::call_once(g_once_flag,  []() {
+        if (!g_settings_sp)
+            g_settings_sp.reset(new TargetProperties(nullptr));
+    });
     return g_settings_sp;
 }
 
diff --git a/lldb/source/Target/Thread.cpp b/lldb/source/Target/Thread.cpp
index f8daf08..5534ab4 100644
--- a/lldb/source/Target/Thread.cpp
+++ b/lldb/source/Target/Thread.cpp
@@ -9,6 +9,7 @@
 
 // C Includes
 // C++ Includes
+#include <mutex>
 // Other libraries and framework includes
 // Project includes
 #include "lldb/Breakpoint/BreakpointLocation.h"
@@ -59,8 +60,11 @@ const ThreadPropertiesSP &
 Thread::GetGlobalProperties()
 {
     static ThreadPropertiesSP g_settings_sp;
-    if (!g_settings_sp)
-        g_settings_sp.reset (new ThreadProperties (true));
+    static std::once_flag g_once_flag;
+    std::call_once(g_once_flag,  []() {
+        if (!g_settings_sp)
+            g_settings_sp.reset (new ThreadProperties (true));
+    });
     return g_settings_sp;
 }
 
-- 
2.7.4