Number of instances running

[ganesh dp]

Is there any way to find how many instance of an applications are running?

[GAJERA]

using EnumWindows API. Which is give the handle of running applications . Get window text from from CWnd * wnd and compare text with your application name.

[ShilpiP]

Click here ->[^] May be this link will help you..

Yes U Can ...If U Can ,Dream it , U can do it ...ICAN

[Sauro Viti]

As long as your code compiles to an exe, you can do it this way:

1. Add the following lines on top of one of your cpp files:

   #pragma data_seg("shared")
   LONG g_counter = 0; // This variable is allocated on a page shared between processes...
   #pragma data_seg()

   #pragma comment(linker, "/section:shared,rws")

2. Execute the following instruction as soon as possible at startup of your application:

   InterlockedIncrement(&g_counter);

3. Execute the following instruction immediately before exiting from your application:

   InterlockedDecrement(&g_counter);

4. When you need the number of instance of your application currently running, use this code:

   LONG instances = InterlockedExchangeAdd(&g_counter, 0);

This method works properly only with exe because they are never relocated while loaded; the trick is to create a section whith the read, write and shared attributes and put there a variable used to count the instances. This way that variable is shared between all the instances of your application, and you can use the Interlocked Variable Access[^] functions to safely access the variable. See also data_seg (C/C++)[^] and /SECTION[^] for more details on how this code works.