#fixed code
                                public static V8 createV8Runtime(final String globalAlias, final String tempDirectory) {
        if (!nativeLibraryLoaded) {
            synchronized (lock) {
                if (!nativeLibraryLoaded) {
                    load(tempDirectory);
                }
            }
        }
        checkNativeLibraryLoaded();
        if (!initialized) {
            _setFlags(v8Flags);
            initialized = true;
        }
        V8 runtime = new V8(globalAlias);
        synchronized (lock) {
            runtimeCounter++;
        }
        return runtime;
    }
#vulnerable code 
                                public static V8 createV8Runtime(final String globalAlias, final String tempDirectory) {
        if (!nativeLibraryLoaded) {
            synchronized (lock) {
                if (!nativeLibraryLoaded) {
                    load(tempDirectory);
                }
            }
        }
        checkNativeLibraryLoaded();
        if (!initialized) {
            _setFlags(v8Flags);
            initialized = true;
        }
        if (debugThread == null) {
            debugThread = Thread.currentThread();
        }
        V8 runtime = new V8(globalAlias);
        synchronized (lock) {
            runtimeCounter++;
        }
        return runtime;
    } 
                            #location 15 
                            #vulnerability type THREAD_SAFETY_VIOLATION