only one user level process accesses this module at anytime. There is only one user level process that uses this module. Amit Kumar Singh/HSS@HSS@nl.linux.org on 06/08/2004 11:07:46 PM Sent by: kernelnewbies-bounce@nl.linux.org To: kernelnewbies@nl.linux.org cc: Subject: functions in a single module HI, I have 6 functions in a single module, some of those are netfilter hook functions, others read/write etc functions for a char device, both type of functions work closely.Plus, I have a couple of timer expiry functions within my module. My doubt is : can functions within a single module pre-empt each other, i use kenel 2.4.20-8, on a uniprocessor system. My read/write char device functions are used by a user level process, the char device is used as a control interface between the module and the user space process. So the user space process sets certain variables using write() on the char device fd. The netfilter hook functions that reside in the same module, use these variables(ones set in the char device driver's write() function ). So as the write function(write()) writes to these shared variable, can a packet come in and the netfilter hook function be called, i.e basically the hook function pre-empts the write() function? Also, what happens when a timer expires, its expiry callback function is called immediately while write() is in progress, or what exactly happens. And if they can/do pre-empt each other then what would be the best strategy to protect these shared variables. thanks Amit "DISCLAIMER: This message is proprietary to Hughes Software Systems Limited (HSS) and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error, please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. HSS accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus." -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
