But wouldn’t a "socket.Accept() " be in fact a loop polling the network for incoming connection ?
I have trouble seeing the difference between my own loop that does not break, but it does with a loop waiting for incoming network connection (I assume its a loop of some kind in the socket library)
So the workaround just delayed the problem, eventually the G120 are unreachable again after a few hours.
I will test some more today to know if if still blocks at socket.Accept()
I added the InstallConstraint() in code snippet I posted earlier
It does not appear to do anything, maybe I don’t use it right?
Still same problem, hit refresh many times in a browser, and eventually it blocks at socket.accept()
using System;
using System.Collections;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Presentation;
using Microsoft.SPOT.Presentation.Controls;
using Microsoft.SPOT.Presentation.Media;
using Microsoft.SPOT.Touch;
using Gadgeteer.Networking;
using GT = Gadgeteer;
using GTM = Gadgeteer.Modules;
using GHINET = GHI.Premium.Net;
using Microsoft.SPOT.Hardware;
using GHI.Premium.Hardware;
using GHI.Premium.Net;
using System.Net;
using System.Net.Sockets;
using System.Text;
using Gadgeteer.Modules.GHIElectronics;
namespace TestNetwork {
public partial class Program {
// This method is run when the mainboard is powered up or reset.
private Thread mainLoopThread;
private Thread serverThread;
private EthernetENC28J60 NetInterface;
private Socket listenSocket;
private Socket serverSocket = null;
void ProgramStarted() {
/*******************************************************************************************
Modules added in the Program.gadgeteer designer view are used by typing
their name followed by a period, e.g. button. or camera.
Many modules generate useful events. Type +=<tab><tab> to add a handler to an event, e.g.:
button.ButtonPressed +=<tab><tab>
If you want to do something periodically, use a GT.Timer and handle its Tick event, e.g.:
GT.Timer timer = new GT.Timer(1000); // every second (1000ms)
timer.Tick +=<tab><tab>
timer.Start();
*******************************************************************************************/
// Use Debug.Print to show messages in Visual Studio's "Output" window during debugging.
Debug.Print("Program Started");
InitNetwork();
mainLoopThread = new Thread(MainLoop);
mainLoopThread.Priority = ThreadPriority.Normal;
mainLoopThread.Start();
}
private void InitNetwork() {
try {
//ethernet_ENC28 = new GHI.Premium.Net.EthernetENC28J60(SPI.SPI_module.SPI2, GHI.Hardware.G120.Pin.P1_17, GHI.Hardware.G120.Pin.P2_21, GHI.Hardware.G120.Pin.P1_14, 4000);
NetInterface = ethernet_ENC28.Interface;
NetInterface.CableConnectivityChanged += new GHI.Premium.Net.EthernetENC28J60.CableConnectivityChangedEventHandler(Interface_CableConnectivityChanged);
NetInterface.NetworkAddressChanged += new GHI.Premium.Net.NetworkInterfaceExtension.NetworkAddressChangedEventHandler(Interface_NetworkAddressChanged);
if (!NetInterface.IsOpen)
NetInterface.Open();
GHI.Premium.Net.NetworkInterfaceExtension.AssignNetworkingStackTo(NetInterface);
byte[] macAddress = new byte[] {0x00, 0x1c, 0x14, 0xf9, 0xda, 0xe9};
for (int i=0;i<6;i++) {
if ( NetInterface.NetworkInterface.PhysicalAddress[i] != macAddress[i] ) {
NetInterface.NetworkInterface.PhysicalAddress = macAddress;
Debug.Print("Updating MAC Address, please reboot for changes to take effect.");
}
}
if (!NetInterface.NetworkInterface.IsDhcpEnabled)
NetInterface.NetworkInterface.EnableDhcp();
NetInterface.NetworkInterface.RenewDhcpLease();
} catch (Exception ex) {
Debug.Print("Error while initializing network" + ex.Message);
}
}
void Interface_NetworkAddressChanged(object sender, EventArgs e) {
Debug.Print("AddressChanged:" + NetInterface.NetworkInterface.IPAddress);
if (NetInterface.NetworkInterface.IPAddress != "0.0.0.0") {
StartServer();
}
}
void Interface_CableConnectivityChanged(object sender, EthernetENC28J60.CableConnectivityEventArgs e) {
Debug.Print("NetworkConnectChanged:" + e.IsConnected);
}
void StartServer() {
serverThread = new Thread(ServerThread);
serverThread.Priority = ThreadPriority.Normal;
serverThread.Start();
}
byte[] request = new byte[65536];
void ServerThread() {
// Bind the listening socket to the port
IPAddress hostIP = IPAddress.Parse(NetInterface.NetworkInterface.IPAddress);
IPEndPoint ep = new IPEndPoint(hostIP, 80);
listenSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
listenSocket.Bind(ep);
// Start listening
listenSocket.Listen(1);
string msgStr = "Hello, browser! I think the time is " + DateTime.Now.ToString();
string responseStr = "";
for (int i = 0; i < 75; i++) {
responseStr = responseStr + "\r" + msgStr;
}
byte[] messageBytes = Encoding.UTF8.GetBytes(responseStr);
ExecutionConstraint.Install((int)(new TimeSpan(0, 0, 5)).Ticks, 0);
// Main thread loop
while (true) {
try {
Debug.Print("listening...");
serverSocket = listenSocket.Accept();
Debug.Print("Accepted a connection from " + serverSocket.RemoteEndPoint.ToString());
} catch (Exception e) {
Debug.Print("Exception @ listenSocket.Accept():" + e.Message);
continue;
}
if (!ReadAll()) {
continue;
}
try {
serverSocket.Send(messageBytes);
} catch (Exception e) {
Debug.Print("Exception @ listenSocket.Send():" + e.Message);
if (ReadAll()) {
}
CloseSocket();
continue;
}
CloseSocket();
serverSocket = null;
}
}
bool ReadAll() {
try {
while (serverSocket.Poll(15000, SelectMode.SelectRead)) {
try {
int numBytes = serverSocket.Receive(request);
if (numBytes == 0) {
break;
}
Debug.Print("Receiving bytes(" + numBytes + "):" + Encoding.UTF8.GetChars(request).ToString());
} catch (Exception e) {
Debug.Print("Exception @ newSock.Receive():" + e.Message);
CloseSocket();
return false;
}
}
} catch (Exception e) {
Debug.Print("Exception @ newSock.Poll():" + e.Message);
CloseSocket();
return false;
}
return true;
}
void CloseSocket() {
try {
serverSocket.Close();
} catch (Exception e) {
Debug.Print("Exception @ newSock.Close():" + e.Message);
}
}
void MainLoop() {
Thread.Sleep(-1);
}
}
}
Couple of things:
- I am only using it on outbound connections. Don’t know if that makes a difference.
- I uninstall the constraint at the end of every attempt.
ie:
ExecutionConstraint.Install(5000, 0);
//Do the stuff that might cause a lockup
ExecutionConstraint.Install(-1, 0);//uninstall constraint
Might be worth trying to move the install part to the beginning of your while loops and put the uninstall part at the end.
I just tried what you mentioned, without success 
It just stays at socket.Accept().
I could try with the G120 being a client , to see if that helps.
I will try also…i can get my to run for 24hours sometimes…and i have an application that does a request every 5 seconds…
It never seems to function more then 12hours most of the time…totally unreliable…i hope we can solve this issue soon?
I think the difference is, that socket.accept() calls a method of unmanaged code, that polls an Input pin.
I remember that I had the same problem with 4.1 too with an ftp client application. When the connection was broken the code did not return. I think, I started socket.accept from a separate thread that could be monitored for normal termination in a certain timespan.
I also tried the ‘watchdog with another thread method’ that will kill the socket thread if it blocks.
The problem is, it will block, and even if I restart the thread with a new socket.Accept(), nothing happens, it just hangs there.
@ PhilM -
have you tried
while (true) {
try
{
ExecutionConstraint.Install((int)(new TimeSpan(0, 0, 5)).Ticks, 0);
serverSocket = listenSocket.Accept();
ExecutionConstraint.Install(-1,0);
}
catch (ConstraintException)
{
Debug.Print("Constraint exception occured");
}
........
}
http://www2.f1.htw-berlin.de/scheibl/netMF/index.htm?./Basis/Schranke.htm
So far, the ConstraintException never happened (I can’t find a way to raise that exception at all!)
You can see in the following image that its stuck at listenSocket.Accept(), and if I try to connect it won’t respond (it did for a few times and eventually it does not respond)
http://s18.postimg.org/fj94bs9rd/network_problem_hang_socketaccept.png
And again this only does this problem with ENC28J60, not with wifi RS21 …
Still unreliable web server…when ever i get this exception…i can no longer get the server to block at
using (connection = server.Accept())
{
....
}
Socket waiting idle..
#### Exception System.Net.Sockets.SocketException - CLR_E_FAIL (9) ####
#### Message:
#### Microsoft.SPOT.Net.SocketNative::poll [IP: 0000] ####
#### System.Net.Sockets.Socket::Poll [IP: 0011] ####
#### System.Net.Sockets.Socket::Accept [IP: 0017] ####
#### SocketException ErrorCode = 10050
#### SocketException ErrorCode = 10050
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in Microsoft.SPOT.Net.dll
Started server in thread 941608925
#### SocketException ErrorCode = 10050
#### SocketException ErrorCode = 10050
..server.Accept() failing
just to add to the story…i am using g120 Cobra 2 board
@ Zigbox, did you tried wifi as well and do you have the same problem ?
Hi,
I did not read your code thoroughly, but can it be that it is the same Problem as in this thread:
https://www.ghielectronics.com/community/forum/topic?id=9878&page=1
In this thread the reason (as I think) was that the socket buffer of the sending device got full.
I can confirm that I often received that exception (#### SocketException ErrorCode = 10050) when using Socket as a client (G120 => to PC)
Although the network was never down, it just broke by itself.
I am using wifi…i will try another wifi network to see if issue continues.
I have tried another wifi network and same issue…
#### Exception System.Net.Sockets.SocketException - CLR_E_FAIL (5) ####
#### Message:
#### Microsoft.SPOT.Net.SocketNative::poll [IP: 0000] ####
#### System.Net.Sockets.Socket::Poll [IP: 0011] ####
#### System.Net.Sockets.Socket::Accept [IP: 0017] ####
#### SocketException ErrorCode = 10050
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in Microsoft.SPOT.Net.dll
#### SocketException ErrorCode = 10050
#### SocketException ErrorCode = 10050
#### SocketException ErrorCode = 10050
We will check to see what we can do,
Thanks
@ zigbox - what is the signal strength reported by your RS9110 module?
For everyones benefit…my DHCP client with Wifi appears to be now working…i didn’t change the code, i just commented out all other code in my application. It appears a reference or some other code is interrupting the wifi for an unknown reason.
I am going to step by step re-enable all my code back to its fullest to determine exactly where the wifi is disrupted. I will everyone know of my findings and hope it helps others.
GHI Forums is very useful and you guys rock!