How to use

tryRelease

method

in

com.mpush.netty.http.HttpConnectionPool

private void writeRequest(Channel channel, RequestContext context) {
  channel.attr(requestKey).set(context);
  pool.attachHost(context.host, channel);
  channel.writeAndFlush(context.request).addListener((ChannelFutureListener) future -> {
    if (!future.isSuccess()) {
      RequestContext info = future.channel().attr(requestKey).getAndSet(null);
      info.tryDone();
      info.onFailure(503, "Service Unavailable");
      LOGGER.debug("request failure request={}", info);
      pool.tryRelease(future.channel());
    }
  });
}

@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
  RequestContext context = ctx.channel().attr(client.requestKey).getAndSet(null);
  try {
    if (context != null && context.tryDone()) {
      context.onException(cause);
    }
  } finally {
    client.pool.tryRelease(ctx.channel());
  }
  LOGGER.error("http client caught an ex, info={}", context, cause);
}

@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
  RequestContext context = ctx.channel().attr(client.requestKey).getAndSet(null);
  try {
    if (context != null && context.tryDone()) {
      LOGGER.debug("receive server response, request={}, response={}", context, msg);
      HttpResponse response = (HttpResponse) msg;
      if (isRedirect(response)) {
        if (context.onRedirect(response)) {
          String location = getRedirectLocation(context.request, response);
          if (location != null && location.length() > 0) {
            context.cancelled.set(false);
            context.request.setUri(location);
            client.request(context);
            return;
          }
        }
      }
      context.onResponse(response);
    } else {
      LOGGER.warn("receive server response but timeout, request={}, response={}", context, msg);
    }
  } finally {
    client.pool.tryRelease(ctx.channel());
    ReferenceCountUtil.release(msg);
  }
}