Comment by DonHopkins | Hacker News Reader

Comment by DonHopkins | Hacker News Reader

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A more realistic example would be the Reiser File System.

https://en.wikipedia.org/wiki/ReiserFS

Note the right-most column:

https://en.wikipedia.org/w/index.php?title=Comparison_of_fil...

I don't value his technical opinions either, but modulo his bullshit about mechanism versus policy (1), I generally agree with most of ESR's points in his review of the X11 chapter, and think Keith Packard and also Jim Gettys deserve credit and have done a wonderful job of rewriting the rendering core, but what they've done is a layer above and independent of and bypassing X (Cairo, Pango, etc, all of which ended up in Firefox, canvas, etc), so it's not a matter of X getting un-broken or cleaning up its act, it's a matter of people packing up their marbles and moving upwards and onwards, to browser and beyond!

(1) Will somebody please explain how XRotateBuffers is "mechanism, not policy"?

https://linux.die.net/man/3/xrotatebuffers

I considered bringing up Hans Reiser and didn't because it conflates what were already discussing with another issue: Support.

Hans Reiser and his tiny company was the primary point of contact for support on ReiserFS. With him in prison no support was left for it, no new updates were coming. This doesn't invalidate the academic legitimacy of his work on "Dancing Trees", other technical topics definitely didn't prevent other file systems from using algorithm advances he came up with.

Now stop mixing stuff that ought not to be mixed. Yes murderers, racists and xenophobes are horrible people, it doesn't make their every last statement wrong.

> Will somebody please explain how XRotateBuffers is "mechanism, not policy"?

XRotateBuffers is implemented using the RotateProperties protocol request, which given a list of property names, will rotate their contents by a given number of places as if the list were circular. This same operation could be done using a sequence of other protocol requests like GetProperty and ChangeProperty. The problem with doing that, though, is that another client attempting to perform the same operation at the same time could have its requests interleaved arbitrarily, leading to corruption or other errors. Each request is performed atomically, so a single request RotateProperties needed to be added to the protocol in order for the rotation operation to be performed safely.

[1] https://www.x.org/releases/X11R7.6/doc/xproto/x11protocol.tx... ; search for "RotateProperties"

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