Regarding tapisrv process

Good Day,
i have opened a device on the linux /dev directory. the same device is opened by the system process "tapisrv". Since tapisrv has issued a *select* system call on that File descriptor that corresponds to that device.. it is basically waiting for a write to occur on it so it can read it.. Now since i opened that device, i also issued a select system call on it.. since i issue the select system call after tapisrv... my process overrides tapisrv and i receive the notification first so i can read it before tapisrv.... however, sometimes it does happen that tapisrv restarts the process or re-issues the select call in which case it over rides my call..

it happens very rarely but sometimes tapisrv wins.. is there a way to gaurantee reading it before tapisrv..?

i would appreciate if someone can provide feedback. This is my first post so please dont let me down...

Thanks alot,

-MAQ

If you're looking to read from a fifo, stream or similar (non-block) device, the data can only be read once. Trying to read/select on read ready from multiple processes is a bad idea. If you really need to read before 'tapisrv', why don't you just insert your code between the two, and reoutput anything you want tapisrv to get ahold of.

Thanks for replying

i am trying to read from /dev/mux device which is a multiplexer or something which reads from the modem as soon as a msg is available. The thing is that Mux device is ready to be read twice. i read it for the first time and then want to decide whether to read it again and the msg will be blocked or let the device native code.. as tapisrv read it and handle it...

how can i insert my code in b/w ? tapisrv is a kernel process built on the phone.. it starts automatically.. are u suggesting me to intercept the process by interfereproc or something or write a kernel code and apply patch ? i cant write kernel code cos i dont know how to apply patch.

is there any other way to insert or intercept tapisrv's code ? do you know something about psuedo tty ? i read about it but dont know what it is or if that can be used to create some master/slave relation

would appreciate your help
thanks