Messages in this thread | | | From | Denis Vlasenko <> | Subject | Re: O_NONBLOCK setting "leak" outside of a process?? | Date | Fri, 2 Feb 2007 00:00:40 +0100 |
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On Tuesday 30 January 2007 04:40, Philippe Troin wrote: > > int main() { > > fcntl(0, F_SETFL, fcntl(0, F_GETFL, 0) | O_NONBLOCK); > > return 0; > > } > > > > int main() { > > fcntl(0, F_SETFL, fcntl(0, F_GETFL, 0) & ~O_NONBLOCK); > > return 0; > > } > > > > If I run "nonblock" in Midnight Commander in KDE's Konsole, > > screen redraw starts to work ~5 times slower. For example, > > Ctrl-O ("show/hide panels" in MC) takes ~0.5 sec to redraw. > > This persists after the program exits (which it > > does immediately as you see). > > Running "block" reverts things to normal. > > > > I mean: how can O_NONBLOCK _issued in a process which > > already exited_ have any effect whatsoever on MC or Konsole? > > They can't even know that it did it, right? > > > > Either I do not know something subtle about Unix or some sort > > of bug is at work. > > Because they all share the same stdin file descriptor, therefore they > share the same file descriptor flags?
What share the same file descriptor? MC and programs started from it?
I thought after exec() fds atre either closed (if CLOEXEC) or becoming independent from parent process (i.e. it you seek, close, etc your fd, parent would not notice that).
Am I wrong? -- vda - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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