On Thu, Feb 20, 2014 at 9:06 PM, <Valdis.Kletnieks@xxxxxx> wrote: > On Thu, 20 Feb 2014 20:36:44 +0530, Rahul Bedarkar said: > >> "Often the open(2) call has unwanted side effects, that can be avoided >> under Linux by giving it the O_NONBLOCK flag." >> >> I have seen open man page but can't find what are side effects of open. > > Well, for starters, the open() call can block while trying to open a hardware > device that isnt ready, thus hanging the entire process. For added joy, > remember that signals are delivered when a process inside a syscall finally > returns to userspace - which means that your hung process may be unkillable > even by 'kill -9'. > Thanks, Does this mean that if I open a device file with O_NONBLOCK flag and if device is not ready by that time open system call will return immediately and fail? > Most people would call that an unwanted side effect. :) _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
