This makes the Scheduler a lot leaner by not having to evaluate
block conditions every time it is invoked. Instead evaluate them as
the states change, and unblock threads at that point.
This also implements some more waitid/waitpid/wait features and
behavior. For example, WUNTRACED and WNOWAIT are now supported. And
wait will now not return EINTR when SIGCHLD is delivered at the
same time.
That's just silly :)
Also fix that one use of read_line() which assumes it will
null-terminated in mount.cpp (this would've blown up if the IODevice was
at EOF and had a line with the same size as max_size).
Problem:
- If `fork()` fails the system tries to call `execl()`. That will
either succeed and replace the running process image or it will fail
and it needs to try again. The `if` is redundant because it will
only be evaluated if `execl()` fails.
Solution:
- Remove the `if`.
Grep supports only extended regular expressions, and is able to handle one pattern
handed over via -e or directly after the options. Also, multiple files can be
handed over. Recursive mode is outstanding, but no real magic :^)
This allows us to check code for syntax errors without relying on
Function(), which can lead to false negatives as certain things are
valid in a function context, but not outside one.
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 :)
> function f(){f()}f()
Uncaught exception: [RuntimeError]: Call stack size limit exceeded
-> f
1234 more calls
-> (global execution context)
> function a(x){if(x>0){a(x-1)}else{throw Error()}}function b(x){if(x>0){b(x-1)}else{a(5)}}function c(){b(2)}c()
Uncaught exception: [Error]
-> a
5 more calls
-> b
-> b
-> b
-> c
-> (global execution context)
