LazyChannelPromise Class — netty Architecture

Source Code

handler/src/main/java/io/netty/handler/ssl/SslHandler.java lines 2451–2474

    private final class LazyChannelPromise extends DefaultPromise<Channel> {

        @Override
        protected EventExecutor executor() {
            if (ctx == null) {
                throw new IllegalStateException();
            }
            return ctx.executor();
        }

        @Override
        protected void checkDeadLock() {
            if (ctx == null) {
                // If ctx is null the handlerAdded(...) callback was not called, in this case the checkDeadLock()
                // method was called from another Thread then the one that is used by ctx.executor(). We need to
                // guard against this as a user can see a race if handshakeFuture().sync() is called but the
                // handlerAdded(..) method was not yet as it is called from the EventExecutor of the
                // ChannelHandlerContext. If we not guard against this super.checkDeadLock() would cause an
                // IllegalStateException when trying to call executor().
                return;
            }
            super.checkDeadLock();
        }
    }