Alan Altmark writes: > On Tuesday, 12/07/2010 at 09:07 EST, Malcolm Beattie <[email protected]> > wrote: > > First of all, I've added an "arrived" > > attribute to ur devices which gets incremented each time a file > > arrives so > > cat /sys/bus/ccw/drivers/vmur/0.0.000c/arrived > > contains a number checkable by scripts or programs (useful in case of > > wakeups or restarts of an app so it can check if anything really > > happened). > > But you're not opening a spool file, you're opening a special character > device.
No, I'm opening a sysfs file--maybe I was unclear. The notification mechanism I'm talking about it is via the sysfs driver model file (/sys/.....) and not the special character device file (/dev/...). The latter is, as both you and I have written, a non-blocking model. In the Linux driver model, device-related notifications can be sent as uevents (broadcast over an AF_NETLINK socket, one of whose listeners is udevd with its configurable rulesets undef /udev) or, more recently, via a POLLPRI condition on a descriptor opened on a sysfs file. Neither of these affects the open/read/write/close behaviour of the special character device file in /dev. Or I may have misunderstood your point? --Malcolm -- Malcolm Beattie Mainframe Systems and Software Business, Europe IBM UK ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
