Update ICU to 54.1 step 1

source/common/locutil.cpp

 /*
  *******************************************************************************
- * Copyright (C) 2002-2011, International Business Machines Corporation and
+ * Copyright (C) 2002-2014, International Business Machines Corporation and
  * others. All Rights Reserved.
  *******************************************************************************
  */
 #include "unicode/utypes.h"
 
 #if !UCONFIG_NO_SERVICE || !UCONFIG_NO_TRANSLITERATION
 
 #include "unicode/resbund.h"
 #include "cmemory.h"
 #include "ustrfmt.h"
 #include "locutil.h"
 #include "charstr.h"
 #include "ucln_cmn.h"
 #include "uassert.h"
 #include "umutex.h"
 
 // see LocaleUtility::getAvailableLocaleNames
+static icu::UInitOnce   LocaleUtilityInitOnce = U_INITONCE_INITIALIZER;
 static icu::Hashtable * LocaleUtility_cache = NULL;
 
 #define UNDERSCORE_CHAR ((UChar)0x005f)
 #define AT_SIGN_CHAR    ((UChar)64)
 #define PERIOD_CHAR     ((UChar)46)
 
 /*
  ******************************************************************
  */
 
 /**
  * Release all static memory held by Locale Utility.  
  */
 U_CDECL_BEGIN
 static UBool U_CALLCONV service_cleanup(void) {
     if (LocaleUtility_cache) {
         delete LocaleUtility_cache;
         LocaleUtility_cache = NULL;
     }
     return TRUE;
 }
+
+
+static void U_CALLCONV locale_utility_init(UErrorCode &status) {
+    using namespace icu;
+    U_ASSERT(LocaleUtility_cache == NULL);
+    ucln_common_registerCleanup(UCLN_COMMON_SERVICE, service_cleanup);
+    LocaleUtility_cache = new Hashtable(status);
+    if (U_FAILURE(status)) {
+        delete LocaleUtility_cache;
+        LocaleUtility_cache = NULL;
+        return;
+    }
+    if (LocaleUtility_cache == NULL) {
+        status = U_MEMORY_ALLOCATION_ERROR;
+        return;
+    }
+    LocaleUtility_cache->setValueDeleter(uhash_deleteHashtable);
+}
+
 U_CDECL_END
 
 U_NAMESPACE_BEGIN
 
 UnicodeString&
 LocaleUtility::canonicalLocaleString(const UnicodeString* id, UnicodeString& result)
 {
   if (id == NULL) {
     result.setToBogus();
   } else {
@@ skipping 130 matching lines @@
 LocaleUtility::getAvailableLocaleNames(const UnicodeString& bundleID)
 {
     // LocaleUtility_cache is a hash-of-hashes.  The top-level keys
     // are path strings ('bundleID') passed to
     // ures_openAvailableLocales.  The top-level values are
     // second-level hashes.  The second-level keys are result strings
     // from ures_openAvailableLocales.  The second-level values are
     // garbage ((void*)1 or other random pointer).
 
     UErrorCode status = U_ZERO_ERROR;
-    Hashtable* cache;
-    umtx_lock(NULL);
-    cache = LocaleUtility_cache;
-    umtx_unlock(NULL);
-
+    umtx_initOnce(LocaleUtilityInitOnce, locale_utility_init, status);
+    Hashtable *cache = LocaleUtility_cache;
     if (cache == NULL) {
-        cache = new Hashtable(status);
-        if (cache == NULL || U_FAILURE(status)) {
-            return NULL; // catastrophic failure; e.g. out of memory
-        }
-        cache->setValueDeleter(uhash_deleteHashtable);
-        Hashtable* h; // set this to final LocaleUtility_cache value
-        umtx_lock(NULL);
-        h = LocaleUtility_cache;
-        if (h == NULL) {
-            LocaleUtility_cache = h = cache;
-            cache = NULL;
-            ucln_common_registerCleanup(UCLN_COMMON_SERVICE, service_cleanup);
-        }
-        umtx_unlock(NULL);
-        if(cache != NULL) {
-          delete cache;
-        }
-        cache = h;
+        // Catastrophic failure.
+        return NULL;
     }
 
-    U_ASSERT(cache != NULL);
-
     Hashtable* htp;
     umtx_lock(NULL);
     htp = (Hashtable*) cache->get(bundleID);
     umtx_unlock(NULL);
 
     if (htp == NULL) {
         htp = new Hashtable(status);
         if (htp && U_SUCCESS(status)) {
             CharString cbundleID;
             cbundleID.appendInvariantChars(bundleID, status);
             const char* path = cbundleID.isEmpty() ? NULL : cbundleID.data();
             UEnumeration *uenum = ures_openAvailableLocales(path, &status);
             for (;;) {
                 const UChar* id = uenum_unext(uenum, NULL, &status);
                 if (id == NULL) {
                     break;
                 }
                 htp->put(UnicodeString(id), (void*)htp, status);
             }
             uenum_close(uenum);
             if (U_FAILURE(status)) {
                 delete htp;
                 return NULL;
             }
             umtx_lock(NULL);
-            cache->put(bundleID, (void*)htp, status);
-            umtx_unlock(NULL);
+            Hashtable *t = static_cast<Hashtable *>(cache->get(bundleID));
+            if (t != NULL) {
+                // Another thread raced through this code, creating the cache entry first.
+                // Discard ours and return theirs.
+                umtx_unlock(NULL);
+                delete htp;
+                htp = t;
+            } else {
+                cache->put(bundleID, (void*)htp, status);
+                umtx_unlock(NULL);
+            }
         }
     }
     return htp;
 }
 
 UBool
 LocaleUtility::isFallbackOf(const UnicodeString& root, const UnicodeString& child)
 {
     return child.indexOf(root) == 0 &&
       (child.length() == root.length() ||
        child.charAt(root.length()) == UNDERSCORE_CHAR);
 }
 
 U_NAMESPACE_END
 
 /* !UCONFIG_NO_SERVICE */
 #endif