<!-- If you need to report a security issue please visit https://github.com/apache/dubbo/security/policy -->

ExtensionLoader cannot be resumed after interruption.

```
java.lang.InterruptedException
  at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1302)
  at java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
  at org.apache.dubbo.common.utils.ClassLoaderResourceLoader.loadResources(ClassLoaderResourceLoader.java:55)
  at org.apache.dubbo.common.extension.ExtensionLoader.loadDirectory(ExtensionLoader.java:1005)
  at org.apache.dubbo.common.extension.ExtensionLoader.loadDirectory(ExtensionLoader.java:943)
  at org.apache.dubbo.common.extension.ExtensionLoader.loadExtensionClasses(ExtensionLoader.java:931)
  at org.apache.dubbo.common.extension.ExtensionLoader.getExtensionClasses(ExtensionLoader.java:913)
  at org.apache.dubbo.common.extension.ExtensionLoader.createExtension(ExtensionLoader.java:752)
  at org.apache.dubbo.common.extension.ExtensionLoader.getExtension(ExtensionLoader.java:548)
  at org.apache.dubbo.common.extension.ExtensionLoader.getExtension(ExtensionLoader.java:523)
  at org.apache.dubbo.rpc.protocol.injvm.InjvmInvoker.<init>(InjvmInvoker.java:74)
```
}
                        set.add(url);
                    }
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            urlCache.put(fileName, set);
        }
        return urlCache.get(fileName);
    }
    public static void destroy() {
        synchronized (ClassLoaderResourceLoader.class) {
            classLoaderResourcesCache = null;
        }
    }
    private static void setRef(URL url) {
        try {
            Field field = URL.class.getDeclaredField("ref");
            field.setAccessible(true);
            field.set(url, UUID.randomUUID().toString());
        } catch (Throwable ignore) {
        }
    }
    
    protected static SoftReference<Map<ClassLoader, Map<String, Set<URL>>>> getClassLoaderResourcesCache() {
        return classLoaderResourcesCache;
    }
}