With this, `ntpquery` can adjust the system time without
making it jump.
A fun activity with this in:
0. Boot
1. Run `su`
2. Run `ntpquery -a` to adjust the time offset after boot
(usually around a second)
3. Keep running `ntpquery ; adjtime` to see how the offset
behind NTP and the remaining adjtime both shrink.
adjtime adjustment is large enough to make the time offset
go down by a bit, but we currently lose time quickly enough
that by the time adjtime is done, we've only corrected the
clock about halfway, and not all the way to zero. Goto 2.
So this isn't all that great yet, but I think it's good enough
to think about turning this into a permanently running service next.
It's a thin userland wrapper around adjtime(2). It can be used
to view current pending time adjustments, and root can use it to
smoothly adjust the system time.
As far as I can tell, other systems don't have a userland utility
for this, but it seems useful. Useful enough that I'm adding it to
the lagom build so I can use it on my linux box too :)
Most systems (Linux, OpenBSD) adjust 0.5 ms per second, or 0.5 us per
1 ms tick. That is, the clock is sped up or slowed down by at most
0.05%. This means adjusting the clock by 1 s takes 2000 s, and the
clock an be adjusted by at most 1.8 s per hour.
FreeBSD adjusts 5 ms per second if the remaining time adjustment is
>= 1 s (0.5%) , else it adjusts by 0.5 ms as well. This allows adjusting
by (almost) 18 s per hour.
Since Serenity OS can lose more than 22 s per hour (#3429), this
picks an adjustment rate up to 1% for now. This allows us to
adjust up to 36s per hour, which should be sufficient to adjust
the clock fast enough to keep up with how much time the clock
currently loses. Once we have a fancier NTP implementation that can
adjust tick rate in addition to offset, we can think about reducing
this.
adjtime is a bit old-school and most current POSIX-y OSs instead
implement adjtimex/ntp_adjtime, but a) we have to start somewhere
b) ntp_adjtime() is a fairly gnarly API. OpenBSD's adjfreq looks
like it might provide similar functionality with a nicer API. But
before worrying about all this, it's probably a good idea to get
to a place where the kernel APIs are (barely) good enough so that
we can write an ntp service, and once we have that we should write
a way to automatically evaluate how well it keeps the time adjusted,
and only then should we add improvements ot the adjustment mechanism.
This makes the game less deterministic and more fun. The "physics"
definitely feel a little goofy, and I'm sure they can be greatly
improved, but still it's already better. :^)
Set the max height of the text_rect to be the height difference
between two icons. Calculate the number of text lines that can be
displayed in this height, and display only that many.
This addresses the issue first enountered in #3644. If a path is
first unveiled with "c" permissions, we should NOT return ENOENT
if the node does not exist on the disk, as the program will most
likely be creating it at a later time.
Problem:
- There is no direct unit testing of the IPv4Address functionality
which makes refactoring difficult.
Solution:
- Add unit tests to cover the current functionality of
IPv4Address. This will allow future refactorings with confidence.
...instead of maybe bitmap + a single mime type and its corresponding data.
This allows drag&drop operations to hold multiple different kinds of
data, and the views/applications to choose between those.
For instance, Spreadsheet can keep the structure of the dragged cells,
and still provide text-only data to be passed to different unrelated editors.
GIFLoader now tracks the state of errors during the decoding process
and will fall back to displaying the first frame of the GIF if any of
the subsequent frames fail to decode.
