bool ScriptLoader::isScriptTypeSupported(LegacyTypeSupport supportLegacyTypes) const
{

    String type = client()->typeAttributeValue();
    String language = client()->languageAttributeValue();
    if (type.isEmpty() && language.isEmpty())
        return true; // Assume text/javascript.
    if (type.isEmpty()) {
        type = "text/" + language.lower();
        if (MIMETypeRegistry::isSupportedJavaScriptMIMEType(type) || isLegacySupportedJavaScriptLanguage(language))
            return true;
    } else if (MIMETypeRegistry::isSupportedJavaScriptMIMEType(type.stripWhiteSpace()) || (supportLegacyTypes == AllowLegacyTypeInTypeAttribute && isLegacySupportedJavaScriptLanguage(type))) {
        return true;
    }

    return false;
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.