[RESOLVED] Automatic Updates for Program

I believe a 'Mutex' can be used to detect existing instances of applications. Give that a google and find out.

Another thing that some programs do is they open up a socket on a weird port, i.e. they'd open a socket on port 63918. If they can't open a socket on that port, they assume there's another instance running.

Hyarion,

Can you help me with how you implemented the other activities like:

Main Program checks version with database or ini file on server.
Main Programs calls a secondary exe for updating and closes itself.
Update program downloads new version
Update program checks that no instances of main program are running
Update program overwrites main program exe file.
Update program calls Main program exe and closes itself.

Actually I am also trying to figure out the similar mechanism for my application, something like smart client. The application would be installed on the client side and should be cabable enough to update any patch or hotfix itself.

Thanks in advance,

Code for using a Mutex to check whether a program is running in order to replace exe file:

In the Main Program's code insert the following - please excuse the tab formatting, I can't seem to get it quite right in these forums :(

[STAThread]

public static void Main(string[] args)
{
//Create Mutex to ensure only one copy of program running.
bool ok;
System.Threading.Mutex m = new System.Threading.Mutex(true, "accint_db", out ok);

if (! ok)
{
MessageBox.Show("Another copy of the program is already running.");
return;
}


Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new MainForm());

GC.KeepAlive(m); //Required to ensure Mutex isn't close prematurely.
}

Code in update program to check for running mutex:

void DoUpdate()
{


if (WaitForMutex() == false)
{
//timeout reached
MessageBox.Show("Unable to copy file, Program still running");

return;

}

//place code here to do update of exe.


}
bool WaitForMutex()
{
int SleepPeriod = 500; //sleep period in milliseconds
int TimeOut = 10; //number of loops before timingout.
int counter = 0;
do
{
//check every 500ms till program is closed
Thread.Sleep(SleepPeriod);
counter++;
if (counter > TimeOut) return false; //timeout period reached
}
while (CheckMutex());
return true; //mutex not found, safe to copy
}

bool CheckMutex()
{
//checks whether the mutex of main program is currently running
bool ok;
System.Threading.Mutex m = new System.Threading.Mutex(true, "accint_db", out ok);
//close mutex after checking.
m.Close();
if (! ok)
{
//Main program is still running
return true;
}
else
{
//No Mutex found
return false;
}
}

I have put a timeout in the mutex checking so that it doesn't just sit there waiting for 4 hours for the program to close. Ideally I want to be able to force the main program to close, but this will do for me for now.

Many thanks to the author of this page:
http://www.ai.uga.edu/mc/SingleInstance.html
as it helped me immensely with explaining the Mutex and how to implement it.

How does the main exe actually self-update? Apart from replacing any new dlls...do we start a self installer?