Simplify GetGlobalProperties functions of Thread/Process/Target

Summary:
"Initialization of function-local statics is guaranteed to occur only once even when called from
multiple threads, and may be more efficient than the equivalent code using std::call_once."
<http://en.cppreference.com/w/cpp/thread/call_once>

I'd add that it's also more readable.

Reviewers: clayborg, zturner

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D17710

llvm-svn: 284601

diff --git a/lldb/source/Target/Process.cpp b/lldb/source/Target/Process.cpp
index 4448ed0..b539ea3 100644 (file)
--- a/lldb/source/Target/Process.cpp
+++ b/lldb/source/Target/Process.cpp
@@ -812,11 +812,8 @@ Process::~Process() {
 const ProcessPropertiesSP &Process::GetGlobalProperties() {
   // NOTE: intentional leak so we don't crash if global destructor chain gets
   // called as other threads still use the result of this function
-  static ProcessPropertiesSP *g_settings_sp_ptr = nullptr;
-  static std::once_flag g_once_flag;
-  std::call_once(g_once_flag, []() {
-    g_settings_sp_ptr = new ProcessPropertiesSP(new ProcessProperties(nullptr));
-  });
+  static ProcessPropertiesSP *g_settings_sp_ptr =
+      new ProcessPropertiesSP(new ProcessProperties(nullptr));
   return *g_settings_sp_ptr;
 }
 

diff --git a/lldb/source/Target/Target.cpp b/lldb/source/Target/Target.cpp
index f4a9119..3fb5300 100644 (file)
--- a/lldb/source/Target/Target.cpp
+++ b/lldb/source/Target/Target.cpp
@@ -2643,11 +2643,8 @@ void Target::RunStopHooks() {
 const TargetPropertiesSP &Target::GetGlobalProperties() {
   // NOTE: intentional leak so we don't crash if global destructor chain gets
   // called as other threads still use the result of this function
-  static TargetPropertiesSP *g_settings_sp_ptr = nullptr;
-  static std::once_flag g_once_flag;
-  std::call_once(g_once_flag, []() {
-    g_settings_sp_ptr = new TargetPropertiesSP(new TargetProperties(nullptr));
-  });
+  static TargetPropertiesSP *g_settings_sp_ptr =
+      new TargetPropertiesSP(new TargetProperties(nullptr));
   return *g_settings_sp_ptr;
 }
 

diff --git a/lldb/source/Target/Thread.cpp b/lldb/source/Target/Thread.cpp
index 676bbf0..10678ec 100644 (file)
--- a/lldb/source/Target/Thread.cpp
+++ b/lldb/source/Target/Thread.cpp
@@ -58,11 +58,8 @@ using namespace lldb_private;
 const ThreadPropertiesSP &Thread::GetGlobalProperties() {
   // NOTE: intentional leak so we don't crash if global destructor chain gets
   // called as other threads still use the result of this function
-  static ThreadPropertiesSP *g_settings_sp_ptr = nullptr;
-  static std::once_flag g_once_flag;
-  std::call_once(g_once_flag, []() {
-    g_settings_sp_ptr = new ThreadPropertiesSP(new ThreadProperties(true));
-  });
+  static ThreadPropertiesSP *g_settings_sp_ptr =
+      new ThreadPropertiesSP(new ThreadProperties(true));
   return *g_settings_sp_ptr;
 }