Re: User-Level upcalls

[manas]

try signal based i/o. basically you have set a signal handler (SIG_IO) and then handle read/write when the signal gets generated. i don't exactly remember the command. it the function call is aio_read/aio_write. check the man thanks manas Anjali Kulkarni wrote: Hi, Thanks a lot for the info. But how can I use poll and select to make the kernel call the user-upcall? Poll and select will run in user-mode and will take processor cycles in busy waiting. I want an event-driven mechanism in which kernel will automatically call the upcall(like an interrupt) when it receives a data packet at the TCP layer, to avoid polling in user code to check if data has arrived at the socket.I will read about kqueues, and fcntl which I dont know much about:) Thanks,Anjali ----- Original Message ----- From: Josh Osborne To: Anjali Kulkarni Sent: Tuesday, June 12, 2001 5:50 PM Subject: Re: User-Level upcalls  On Tuesday, June 12, 2001, at 05:34 AM, Anjali Kulkarni wrote:   <?fontfamily><?param Arial><?smaller>hi,<?/smaller><?/fontfamily> <?fontfamily><?param Arial><?smaller>Does any one know how to perform user-level upcalls from kernel TCP/IP stack? If I wanted to get an upcall every time a data packet arrived on a socket, how can it be done? Can I use signal handlers for this?<?/smaller><?/fontfamily> <?fontfamily><?param Arial><?smaller>Thanks,<?/smaller><?/fontfamily> <?fontfamily><?param Arial><?smaller>Anjali<?/smaller><?/fontfamily> kqueue is the nicest interface, but new and not as portable as others. poll and select are more traditional, and popular. you can also try fcntl's O_ASYNC flag, but I have never used it.