Hello Jonathan! On Wednesday 03 August 2011, Jonathan Nieder wrote: > Philipp Marek wrote: > > I think that on sockets, pipes, character devices, and similar there > > should be _no_ readahead. > > On the contrary, on sockets and pipes, readahead is very useful. > Luckily buffering there works a little closer to what you would expect > --- read() returns early with what is available and fgetc happily > makes use of the result without reading again. Sorry, I did not make myself clear.
If there are multiple programs accessing the handle it's _vital_ for sockets, cdevs and pipes that only the needed amount is read; files and block devices can be seek()ed, but data read from one stream is _lost_ for everybody else! Think about a process reading authentication information, then starting a different program for handling the stream (authenticated inetd, if you like); if the fread() got more than just the authentication information, the other process will not get the handshake! I believe that fgetc() and fgets() shouldn't do prefetching on file handles with "volatile" data. > So I agree with Petr on this one. How about this patch? It will also > help on every other unix supporting /dev/random I know of. Well, ECL is fixed in that a different fix is already in git, but thank you nonetheless! -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
