replace double-checked locking patterns with thread safe local statics

Change-Id: I1bf67196e97411aeecc13ed4f91d1088a315e323
Reviewed-on: https://gerrit.libreoffice.org/62839
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

2 files changed, 19 insertions, 30 deletions

diff --git a/sal/rtl/bootstrap.cxx b/sal/rtl/bootstrap.cxx
index 5e0769c99630..897de890d890 100644
--- a/sal/rtl/bootstrap.cxx
+++ b/sal/rtl/bootstrap.cxx
@@ -227,10 +227,7 @@ static void getExecutableDirectory_Impl(rtl_uString ** ppDirURL)
 
 static OUString & getIniFileName_Impl()
 {
-    osl::MutexGuard guard(osl::Mutex::getGlobalMutex());
-    static OUString *pStaticName = nullptr;
-    if (!pStaticName)
-    {
+    static OUString aStaticName = []() {
         OUString fileName;
 
 #if defined IOS
@@ -284,14 +281,10 @@ static OUString & getIniFileName_Impl()
         }
 #endif
 
-        static OUString theFileName;
-        if (fileName.getLength())
-            theFileName = fileName;
-
-        pStaticName = &theFileName;
-    }
+        return fileName;
+    }();
 
-    return *pStaticName;
+    return aStaticName;
 }
 
 // ensure the given file url has no final slash
@@ -395,20 +388,17 @@ namespace {
 
 Bootstrap_Impl * get_static_bootstrap_handle()
 {
-    osl::MutexGuard guard(osl::Mutex::getGlobalMutex());
-    static Bootstrap_Impl * s_handle = nullptr;
-    if (!s_handle)
-    {
+    static Bootstrap_Impl* s_handle = []() {
         OUString iniName(getIniFileName_Impl());
-        s_handle = static_cast< Bootstrap_Impl * >(
-            rtl_bootstrap_args_open(iniName.pData));
-        if (!s_handle)
+        Bootstrap_Impl* that = static_cast<Bootstrap_Impl*>(rtl_bootstrap_args_open(iniName.pData));
+        if (!that)
         {
-            Bootstrap_Impl * that = new Bootstrap_Impl( iniName );
+            that = new Bootstrap_Impl(iniName);
             ++that->_nRefCount;
-            s_handle = that;
         }
-    }
+        return that;
+    }();
+
     return s_handle;
 }
 
diff --git a/sal/rtl/uuid.cxx b/sal/rtl/uuid.cxx
index 632b842f6391..bb9490ef8b99 100644
--- a/sal/rtl/uuid.cxx
+++ b/sal/rtl/uuid.cxx
@@ -93,19 +93,18 @@ extern "C" void SAL_CALL rtl_createUuid(sal_uInt8 *pTargetUUID ,
                                         SAL_UNUSED_PARAMETER sal_Bool)
 {
     {
-        osl::MutexGuard g(osl::Mutex::getGlobalMutex());
-        static rtlRandomPool pool = nullptr;
-        if (!pool)
-        {
-            pool = rtl_random_createPool();
-            if (!pool)
+        static rtlRandomPool pool = []() {
+            rtlRandomPool aPool = rtl_random_createPool();
+            if (!aPool)
             {
                 abort();
-                    // only possible way to signal failure here (rtl_createUuid
-                    // being part of a fixed C API)
+                // only possible way to signal failure here (rtl_createUuid
+                // being part of a fixed C API)
             }
-        }
+            return aPool;
+        }();
 
+        osl::MutexGuard g(osl::Mutex::getGlobalMutex());
         if (rtl_random_getBytes(pool, pTargetUUID, 16) != rtl_Random_E_None)
         {
             abort();