code: private ReentrantReadWriteLock getFileLock(String jspVfsName) {
  
          ReentrantReadWriteLock lock = m_fileLocks.get(jspVfsName);
          if (lock == null) {
              // acquire the purge lock before adding new file lock entries
              // in case of a JSP repository purge, adding new file lock entries is blocked
              // and all present file locks will be locked for purge
              // @see #triggerPurge()
              m_purgeLock.readLock().lock();
              synchronized (m_fileLocks) {
                  if (!m_fileLocks.containsKey(jspVfsName)) {
                      m_fileLocks.put(jspVfsName, new ReentrantReadWriteLock(true));
                  }
                  lock = m_fileLocks.get(jspVfsName);
              }
              m_purgeLock.readLock().unlock();
          }
          return lock;
      }
docs: Returns the read-write-lock for the given jsp vfs name.<p>
  
  @param jspVfsName the jsp vfs name
  
  @return the read-write-lock