Question

It should not be possible to run multiple instances of my application. Therefore the project source contains:

CreateMutex (nil, False, PChar (ID));
if (GetLastError = ERROR_ALREADY_EXISTS) then
  Halt;

Now I want to restart my application programmatically. The usual way would be:

AppName := PChar(Application.ExeName) ;
ShellExecute(Handle,'open', AppName, nil, nil, SW_SHOWNORMAL) ;
Application.Terminate;

But this won’t work in my case because of the mutex. Even if I release the mutex before starting the second instace it won’t work because shutdown takes some time and two instance cannot run in parallel (because of common resources and other effects).

Is there a way to restart an application with such characteristics? (If possible without an additional executable)

Thanks in advance.

Answer 1

Perhaps you should think outside the box. Instead of futzing with the mutex / instance logic, you could simply create another executable that waits for your app to close then starts it again. As an added bonus, you can later use this mechanism to, for example, update some of your main app’s binaries. It’s also much easier to run it elevated instead of maintaining different integrity levels inside the same app, etc.