sockets

问题 I'm developing an Android app than can transmit data to a 4.0 Bluetooth serial device. I'm guiding by LeGatt android sample project (http://developer.android.com/samples/BluetoothLeGatt/index.html). In this project, they connect to the device, but nothing about transmission data. For 2.0 bluetooth I can create a Socket, InputStream and OutputStream to transmit the data, something like this: protected BluetoothSocket mySocket = null; private InputStream MyInStream; private OutputStream

问题 Port 8888 is already bound on my (OS X 10.13.5) system, by a process running inside a docker container: $ netstat -an | grep 8888 tcp6 0 0 ::1.8888 *.* LISTEN tcp4 0 0 *.8888 *.* LISTEN A python program which tries to bind to that port (using as close to the socket options of golang as I can manage), fails in the way I expect: import socket import fcntl import os def main(): sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) flag = fcntl.fcntl(sock.fileno(), fcntl.F_GETFL) fcntl.fcntl

问题 Port 8888 is already bound on my (OS X 10.13.5) system, by a process running inside a docker container: $ netstat -an | grep 8888 tcp6 0 0 ::1.8888 *.* LISTEN tcp4 0 0 *.8888 *.* LISTEN A python program which tries to bind to that port (using as close to the socket options of golang as I can manage), fails in the way I expect: import socket import fcntl import os def main(): sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) flag = fcntl.fcntl(sock.fileno(), fcntl.F_GETFL) fcntl.fcntl

问题 Port 8888 is already bound on my (OS X 10.13.5) system, by a process running inside a docker container: $ netstat -an | grep 8888 tcp6 0 0 ::1.8888 *.* LISTEN tcp4 0 0 *.8888 *.* LISTEN A python program which tries to bind to that port (using as close to the socket options of golang as I can manage), fails in the way I expect: import socket import fcntl import os def main(): sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) flag = fcntl.fcntl(sock.fileno(), fcntl.F_GETFL) fcntl.fcntl

问题 In this old project (from 2002), It says that if you split a file into multiple chunks and then transmit each chunk using a different socket, it will arrive much faster than transmitting it as a whole using one socket. I also remember reading (many years ago) that some download manager also uses this technique. How accurate is this? 回答1: Given that a single TCP connection with large windows or small RTT can saturate any network link, I don't see what benefit you expect from multiple TCP

问题 In this old project (from 2002), It says that if you split a file into multiple chunks and then transmit each chunk using a different socket, it will arrive much faster than transmitting it as a whole using one socket. I also remember reading (many years ago) that some download manager also uses this technique. How accurate is this? 回答1: Given that a single TCP connection with large windows or small RTT can saturate any network link, I don't see what benefit you expect from multiple TCP

问题 I have not been able to find a satisfying answer to this question anywhere. Could someone with an understanding of the internals please explain this? I wrote a simple client/server to demonstrate this issue. The server reads one line of text then closes the socket. The client writes one line of text, waits 10 seconds, then writes two more lines of text. The second write (after 10 seconds) fails but the first write always succeeds. Why can't the BufferedWriter throw an exception on the first

问题 I've got an application that needs to send a stream of data from one process to multiple readers, each of which needs to see its own copy of the stream. This is reasonably high-rate (100MB/s is not uncommon), so I'd like to avoid duplication if possible. In my ideal world, linux would have named pipes that supported multiple readers, with a fast path for the common single-reader case. I'd like something that provides some measure of namespace isolation (eg: broadcasting on 127.0.0.1 is open

问题 I am currently trying to use socket.io and a node.js server to communicate with a Unity script. I have everything hooked up and working with localhost, but for some reason when I port it to my Heroku server it can't connect. I'm assuming it might have something to do with the URL's? I'm new to socket.io so any help would be appreciated. My node.js server: var express = require('express'); var app = express(); var expressWs = require('express-ws')(app); var path = require('path'); var server =

问题 I have a client application, which uses a unmanaged dll for communicating with a server. All network-related operations are perormed inside the unmanaged dll. After a number of operations with the server, the client is running out of TCP ports. If we check the state of netwotk using 'netstat -an', we get the following result: ... TCP 192.168.11.55:56048 192.168.10.28:5000 FIN_WAIT_2 TCP 192.168.11.55:56049 192.168.10.28:5000 FIN_WAIT_2 TCP 192.168.11.55:56050 192.168.10.28:5000 FIN_WAIT_2 TCP