Question

Good day!
I’m working on installer, which installs additional dependencies for my software using Process.Start.

foreach dependency:
var process = System.Diagnostics.Process.Start(processStartInfo);
process.WaitForExit();

The problem is when another msi installation is runned, WaitForExit hangs (and when I close this another msi installation, WaitForExit also exits).

I can’t use timeouts, because dependencies are different with very different installation time.

Is there any ways to handle this situation and correctly kill process (actually I want to know is dependency is installing or just hanging)?
Many thanks.

Solution: in my case the problem is solved by checking if ‘msiexec’ process is running.

Answer 1

The solution to my problem – check global mutex, created by msiexec. This is also a correct way to check if another msi installation is running.

    public static bool WaitAnotherMsiInstallation(int timeout)
    {
        const string MsiMutexName = "Global\\_MSIExecute";

        try
        {
            using (var msiMutex = Mutex.OpenExisting(MsiMutexName, MutexRights.Synchronize))
            {
                return msiMutex.WaitOne(timeout);
            }
        } 
        catch (WaitHandleCannotBeOpenedException)
        {
            // The named mutex does not exist.
            return true;
        }
        catch (ObjectDisposedException)
        {
            // Mutex was disposed between opening it and attempting to wait on it
            return true;
        }
    }

Here is some details http://msdn.microsoft.com/en-us/library/aa372909(VS.85).aspx