On Mon, 10 Jun 2002, Maksim Yevmenkin wrote: MY>Hackers, MY> MY>The project i'm working on might require some sort of MY>device cloning. The current way of cloning, i.e. use MY>DEVFS and allocate unique minor numbers, is not very MY>good for my purpose. MY> MY>The idea is simple: the same device(major,minor) can MY>be opened several times by different processes (or MY>possibly threads within the same process) and each MY>process (thread) will have unique device instance. MY>Device driver will create new instance, every time MY>open() called. It will use D_TRACKCLOSE flag and MY>destroy instances in close(). MY> MY>What kind of information should i store to identify MY>each instance? Is/Will it be possible to identify a MY>single thread within a process? Is there any problems MY>with fork()? The support for the threads is optional. MY>I can live with single instance per process.
In MHO this idea is based on a fundamental misunderstanding of what a device is under unix. If you need such a behaviour you should put another abstraction on top of you devices (as the filesystem is put on top of disks and sockets on top of network devices), that handle multiple contexts for multiple processes. A device is just a device... harti -- harti brandt, http://www.fokus.gmd.de/research/cc/cats/employees/hartmut.brandt/private [EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message