public void run() {
                        if (serverCallStreamObserver.isReady() && wasReady.compareAndSet(false, true)) {
                            logger.info("READY");
                            // Signal the request sender to send one message. This happens when isReady() turns true, signaling that
                            // the receive buffer has enough free space to receive more messages. Calling request() serves to prime
                            // the message pump.
                            serverCallStreamObserver.request(1);
                        }
                    }
copy grpc framework
- https://github.com/grpc/grpc-java/blob/master/examples/src/main/java/io/grpc/examples/manualflowcontrol/ManualFlowControlServer.java
agent-module/plugins-it/google-grpc-it/google-grpc-1-8-it/src/test/java/com/navercorp/pinpoint/it/plugin/grpc/HelloWorldStreamServer.java