> From: [EMAIL PROTECTED] (Paul Jarc) > Date: Fri, 09 Aug 2002 14:25:20 -0400 > > Derek Robert Price <[EMAIL PROTECTED]> wrote: > > I assume they have different file table entries in the kernel > > because stderr can be set to nonblock without doing the same to > > stdout. I need to know when the two file descriptors point to the > > same file table entry (i.e. $ cvs <whatever> 2>&1). > > Ah. So frob the flags on one of them and see if the other one changes > too; then restore the original flags. This still isn't perfect, for > the same reason that the problem exists: another process with a copy > of the same descriptor could be messing around with flags at the same > time. But that seems unlikely in the cases where the problem appears.
Since (as you mention) this optimization isn't safe, then I wouldn't do it. For this particular application, it's just an optimization to check for the same file table entries; it's OK to omit the optimization if it isn't safe. In contrast, the st_dev+st_ino optimization is safe, since it doesn't make any assumptions about what other processes are doing. _______________________________________________ Bug-cvs mailing list [EMAIL PROTECTED] http://mail.gnu.org/mailman/listinfo/bug-cvs
