I was addressing how to deal with crashed files vs. not crashed files using polling for a single application, not for using polling as a communication medium between two apps. So in this case, the "second instance" is really not a second running instance of the same application, but a relaunching of the application because it crashed.
But in answer to your question, it woudl be because both instances of the app are preprogrammed (either hard-coded or via a prefs file) to look in the same place for files. For example, I have two apps that talk to each other using a common folder for polling. App 1 looks for a file called "app1.cmd" in the folder, and App 2 looks for a file called "app2.cmd" in the folder. Since they are looking for different files, there's no collision. If App 2 writes the "app1.cmd" file to "tell" App 1 something, and App 1 had previously crashed, the file would stay in the folder with the timestamp. When App 1 was relaunched, it would see that file, but since it was sent prior to its launch date, a decision can then be made (either ignore it - if App 1 was very time-sensitive for example, or process it - if it doesn't matter when App 1 gets the message). Ken Ray Sons of Thunder Software Email: [EMAIL PROTECTED] Web Site: http://www.sonsothunder.com/ ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, December 03, 2002 2:55 PM Subject: Re: launching on Wintel/inter-process communication > > Simple. Write the milliseconds into the file. Then, when the app launches, > > grab the milliseconds as its "launch date". When it goes to look in the > > folder, it will read in the "leftover" file, but because the milliseconds > > in > > the leftover is *earlier* than the launch date, it is ignored. It will only > > read files written into the "watched" folder *after* the launch date. > > > The time stamp seems logical- but here's my question: how does a second > instance of the application know what file to look for? That is, if the file > is already there from the first instance which was launched hours ago, how > can it tell the difference between that file and a crashed one. Without using > inter-application communication of course =). > > Or am I missing something? > > Brian > > > _______________________________________________ metacard mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/metacard
