59     }
  60     private AsynchronousChannelProvider(Void ignore) { }
  61 
  62     /**
  63      * Initializes a new instance of this class.
  64      *
  65      * @throws  SecurityException
  66      *          If a security manager has been installed and it denies
  67      *          {@link RuntimePermission}<tt>("asynchronousChannelProvider")</tt>
  68      */
  69     protected AsynchronousChannelProvider() {
  70         this(checkPermission());
  71     }
  72 
  73     // lazy initialization of default provider
  74     private static class ProviderHolder {
  75         static final AsynchronousChannelProvider provider = load();
  76 
  77         private static AsynchronousChannelProvider load() {
  78             return AccessController
  79                 .doPrivileged(new PrivilegedAction<AsynchronousChannelProvider>() {
  80                     public AsynchronousChannelProvider run() {
  81                         AsynchronousChannelProvider p;
  82                         p = loadProviderFromProperty();
  83                         if (p != null)
  84                             return p;
  85                         p = loadProviderAsService();
  86                         if (p != null)
  87                             return p;
  88                         return sun.nio.ch.DefaultAsynchronousChannelProvider.create();
  89                     }});
  90         }
  91 
  92         private static AsynchronousChannelProvider loadProviderFromProperty() {
  93             String cn = System.getProperty("java.nio.channels.spi.AsynchronousChannelProvider");
  94             if (cn == null)
  95                 return null;
  96             try {
  97                 Class<?> c = Class.forName(cn, true,
  98                                            ClassLoader.getSystemClassLoader());
  99                 return (AsynchronousChannelProvider)c.newInstance();

  59     }
  60     private AsynchronousChannelProvider(Void ignore) { }
  61 
  62     /**
  63      * Initializes a new instance of this class.
  64      *
  65      * @throws  SecurityException
  66      *          If a security manager has been installed and it denies
  67      *          {@link RuntimePermission}<tt>("asynchronousChannelProvider")</tt>
  68      */
  69     protected AsynchronousChannelProvider() {
  70         this(checkPermission());
  71     }
  72 
  73     // lazy initialization of default provider
  74     private static class ProviderHolder {
  75         static final AsynchronousChannelProvider provider = load();
  76 
  77         private static AsynchronousChannelProvider load() {
  78             return AccessController
  79                 .doPrivileged(new PrivilegedAction<>() {
  80                     public AsynchronousChannelProvider run() {
  81                         AsynchronousChannelProvider p;
  82                         p = loadProviderFromProperty();
  83                         if (p != null)
  84                             return p;
  85                         p = loadProviderAsService();
  86                         if (p != null)
  87                             return p;
  88                         return sun.nio.ch.DefaultAsynchronousChannelProvider.create();
  89                     }});
  90         }
  91 
  92         private static AsynchronousChannelProvider loadProviderFromProperty() {
  93             String cn = System.getProperty("java.nio.channels.spi.AsynchronousChannelProvider");
  94             if (cn == null)
  95                 return null;
  96             try {
  97                 Class<?> c = Class.forName(cn, true,
  98                                            ClassLoader.getSystemClassLoader());
  99                 return (AsynchronousChannelProvider)c.newInstance();