如果连接时抛出 SslHandshakeTimeoutException 异常，那么 ApnsChannelPool pendingCreateChannelFutures 会一直被占有 about pushy HOT 7 CLOSED

ApnsClientBuilder apnsClientBuilder = new ApnsClientBuilder();
... 
apnsClientBuilder.setConcurrentConnections(8)
	.setEventLoopGroup(eventLoopGroup)
	.setConnectionTimeout(Duration.ofSeconds(10)) // 设置 10 秒超时
	.setIdlePingInterval(Duration.ofSeconds(5))
	.setFrameLogger(new Http2FrameLogger(LogLevel.DEBUG, "PUSHY"))
	.setMetricsListener(new MyApnsClientMetricsListener());
ApnsClient apnsClient = apnsClientBuilder.build();

      PushNotificationFuture<SimpleApnsPushNotification, PushNotificationResponse<SimpleApnsPushNotification>>
	    sendNotificationFuture = apnsClient.sendNotification(pushNotification);
      try {
    		final PushNotificationResponse<SimpleApnsPushNotification> pushNotificationResponse = sendNotificationFuture.get(3, TimeUnit.SECONDS);

    		if (pushNotificationResponse.isAccepted()) {
    			log.info("push success. Push notification accepted by APNs gateway. token="+pushNotification.getToken());
    		} else {
    			log.error("push failed. Notification rejected by the APNs gateway: " + pushNotificationResponse.getRejectionReason() + ",token="+pushNotification.getToken());
    			pushNotificationResponse.getTokenInvalidationTimestamp().ifPresent(timestamp -> {
    				log.error("\t…and the token is invalid as of " + timestamp + ",token="+pushNotification.getToken());
    			});
    		}
    	} catch (final ExecutionException e) {
    		log.error("Failed to send push notification.",e);
    	} catch (InterruptedException | TimeoutException e) {
    		log.error("sendNotificationFuture.get() 中断或超时异常",e);
    	}

sendNotificationFuture.get() 中断或超时异常
java.util.concurrent.TimeoutException: null
	at java.util.concurrent.CompletableFuture.timedGet(CompletableFuture.java:1771)
	at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1915)

api.push.apple.com could not be resolved (110: Operation timed out)

io.netty.handler.ssl.SslHandshakeTimeoutException: handshake timed out after 10000ms
	at io.netty.handler.ssl.SslHandler$7.run(SslHandler.java:2125)
	at io.netty.util.concurrent.PromiseTask.runTask(PromiseTask.java:98)
	at io.netty.util.concurrent.ScheduledFutureTask.run(ScheduledFutureTask.java:153)
	at io.netty.util.concurrent.AbstractEventExecutor.runTask$$$capture(AbstractEventExecutor.java:174)
	at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute$$$capture(AbstractEventExecutor.java:167)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:569)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.lang.Thread.run(Thread.java:745)

    public void userEventTriggered(final ChannelHandlerContext context, final Object event) throws Exception {
        // 这里是调整的代码
        if(event instanceof SslHandshakeCompletionEvent){
            Throwable cause = ((SslHandshakeCompletionEvent) event).cause();
            if(cause != null && cause instanceof SslHandshakeTimeoutException){
                log.error("SslHandshakeTimeoutException,channel:{}会被关闭:{}",context.channel(),cause.getMessage());
                context.voidPromise().tryFailure(cause);
            }
        }
       ....
    }

private void applyHandshakeTimeout() {
        final Promise<Channel> localHandshakePromise = this.handshakePromise;

        // Set timeout if necessary.
        final long handshakeTimeoutMillis = this.handshakeTimeoutMillis;
        if (handshakeTimeoutMillis <= 0 || localHandshakePromise.isDone()) {
            return;
        }

        final Future<?> timeoutFuture = ctx.executor().schedule(new Runnable() {
            @Override
            public void run() {
                if (localHandshakePromise.isDone()) {
                    return;
                }
                SSLException exception =
                        new SslHandshakeTimeoutException("handshake timed out after " + handshakeTimeoutMillis + "ms");
                try {
                    if (localHandshakePromise.tryFailure(exception)) {
                        SslUtils.handleHandshakeFailure(ctx, exception, true);
                    }
                } finally {
                    releaseAndFailAll(ctx, exception);
                }
            }
        }, handshakeTimeoutMillis, TimeUnit.MILLISECONDS);

        // Cancel the handshake timeout when handshake is finished.
        localHandshakePromise.addListener(new FutureListener<Channel>() {
            @Override
            public void operationComplete(Future<Channel> f) throws Exception {
                timeoutFuture.cancel(false);
            }
        });
    }

 public void exceptionCaught(final ChannelHandlerContext context, final Throwable cause) {
        // Always try to fail the "channel ready" promise if we catch an exception; in some cases, these may happen
        // after a connection has already become ready, in which case the failure attempt will have no effect.
        getChannelReadyPromise(context.channel()).tryFailure(cause);
    }

getChannelReadyPromise(context.channel()).tryFailure(cause);