commit 798ffa953a1ff85dabd816271c96223c1d1e2a5d
author Stephen Webb <stephen.webb@ieee.org> Mon Jan 24 13:23:17 2022 +1100
committer GitHub <noreply@github.com> Mon Jan 24 13:23:17 2022 +1100
tree 1408129f8f7804fe461bc1e63a877103fd613ae9
parent 09b5b723a1a210c28bf8b05b0676bb2b104359ba

Prevent static initialization order faults by using local statics (#105)

Prevent static initialization order faults by using local statics which are thread safe since C++11

src/main/cpp/level.cpp

diff --git a/src/main/cpp/level.cpp b/src/main/cpp/level.cpp
index 8c739c1..f2fb91d 100644
--- a/src/main/cpp/level.cpp
+++ b/src/main/cpp/level.cpp
@@ -30,89 +30,52 @@
 
 IMPLEMENT_LOG4CXX_OBJECT_WITH_CUSTOM_CLASS(Level, LevelClass)
 
-volatile bool Level::initialized = false;
-std::mutex Level::initMutex;
-LevelPtr Level::allLevel;
-LevelPtr Level::fatalLevel;
-LevelPtr Level::errorLevel;
-LevelPtr Level::warnLevel;
-LevelPtr Level::infoLevel;
-LevelPtr Level::debugLevel;
-LevelPtr Level::traceLevel;
-LevelPtr Level::offLevel;
-
-void Level::initializeLevels()
-{
-	if ( initialized )
-	{
-		return;
-	}
-
-	std::unique_lock<std::mutex> lock(initMutex);
-
-	if ( initialized )
-	{
-		return;
-	}
-
-	allLevel   = LevelPtr(new Level(Level::ALL_INT, LOG4CXX_STR("ALL"), 7));
-	fatalLevel = LevelPtr(new Level(Level::FATAL_INT, LOG4CXX_STR("FATAL"), 0));
-	errorLevel = LevelPtr(new Level(Level::ERROR_INT, LOG4CXX_STR("ERROR"), 3));
-	warnLevel  = LevelPtr(new Level(Level::WARN_INT, LOG4CXX_STR("WARN"), 4));
-	infoLevel  = LevelPtr(new Level(Level::INFO_INT, LOG4CXX_STR("INFO"), 6));
-	debugLevel = LevelPtr(new Level(Level::DEBUG_INT, LOG4CXX_STR("DEBUG"), 7));
-	traceLevel = LevelPtr(new Level(Level::TRACE_INT, LOG4CXX_STR("TRACE"), 7));
-	offLevel   = LevelPtr(new Level(Level::OFF_INT, LOG4CXX_STR("OFF"), 0));
-
-	initialized = true;
-}
-
 LevelPtr Level::getOff()
 {
-	initializeLevels();
+	static LevelPtr offLevel(new Level(Level::OFF_INT, LOG4CXX_STR("OFF"), 0));
 	return offLevel;
 }
 
 LevelPtr Level::getFatal()
 {
-	initializeLevels();
+	static LevelPtr fatalLevel(new Level(Level::FATAL_INT, LOG4CXX_STR("FATAL"), 0));
 	return fatalLevel;
 }
 
 LevelPtr Level::getError()
 {
-	initializeLevels();
+	static LevelPtr errorLevel(new Level(Level::ERROR_INT, LOG4CXX_STR("ERROR"), 3));
 	return errorLevel;
 }
 
 LevelPtr Level::getWarn()
 {
-	initializeLevels();
+	static LevelPtr warnLevel(new Level(Level::WARN_INT, LOG4CXX_STR("WARN"), 4));
 	return warnLevel;
 }
 
 LevelPtr Level::getInfo()
 {
-	initializeLevels();
+	static LevelPtr infoLevel(new Level(Level::INFO_INT, LOG4CXX_STR("INFO"), 6));
 	return infoLevel;
 }
 
 LevelPtr Level::getDebug()
 {
-	initializeLevels();
+	static LevelPtr debugLevel(new Level(Level::DEBUG_INT, LOG4CXX_STR("DEBUG"), 7));
 	return debugLevel;
 }
 
 LevelPtr Level::getTrace()
 {
-	initializeLevels();
+	static LevelPtr traceLevel(new Level(Level::TRACE_INT, LOG4CXX_STR("TRACE"), 7));
 	return traceLevel;
 }
 
 
 LevelPtr Level::getAll()
 {
-	initializeLevels();
+	static LevelPtr allLevel(new Level(Level::ALL_INT, LOG4CXX_STR("ALL"), 7));
 	return allLevel;
 }
 
@@ -313,11 +276,11 @@
 
 bool Level::equals(const LevelPtr& level1) const
 {
-	return (this->level == level1->level);
+	return level1 && this->level == level1->level;
 }
 
 bool Level::isGreaterOrEqual(const LevelPtr& level1) const
 {
-	return this->level >= level1->level;
+	return level1 && this->level >= level1->level;
 }
 

src/main/include/log4cxx/level.h

diff --git a/src/main/include/log4cxx/level.h b/src/main/include/log4cxx/level.h
index 7848c90..b89a604 100644
--- a/src/main/include/log4cxx/level.h
+++ b/src/main/include/log4cxx/level.h
@@ -224,7 +224,6 @@
 		};
 
 
-		static void initializeLevels();
 		static LevelPtr getAll();
 		static LevelPtr getFatal();
 		static LevelPtr getError();
@@ -279,18 +278,6 @@
 			return level;
 		}
 
-	private:
-		static volatile bool initialized;
-		static std::mutex initMutex;
-		static LevelPtr allLevel;
-		static LevelPtr fatalLevel;
-		static LevelPtr errorLevel;
-		static LevelPtr warnLevel;
-		static LevelPtr infoLevel;
-		static LevelPtr debugLevel;
-		static LevelPtr traceLevel;
-		static LevelPtr offLevel;
-
 		int level;
 		LogString name;
 		int syslogEquivalent;