* This removes duplicated code that adjusts the sort direction from every
OS-specific folder.
* Most fields in a regular htop screen are OS-independent, so trying
Process_compare first and only falling back to the OS-specific
compareByKey function if it's an OS-specific field makes sense.
* This will allow us to override the sortKey in a global way without having
to edit each OS-specific file.
RichString_writeFrom takes a top spot during performance analysis due to the
calls to mbstowcs() and iswprint().
Most of the time we know in advance that we are only going to print regular
ASCII characters.
If currently two unsigned values are compared via `a - b`, in the case b
is actually bigger than a, the result will not be an negative number (as
-1 is expected) but a huge positive number as the subtraction is an
unsigned subtraction.
Avoid over-/underflow affected operations; use comparisons.
Modern compilers will generate sane code, like:
xor eax, eax
cmp rdi, rsi
seta al
sbb eax, 0
ret
Reasoning:
- implementation was unsound -- broke down when I added a fairly
basic macro definition expanding to a struct initializer in a *.c
file.
- made it way too easy (e.g. via otherwise totally innocuous git
commands) to end up with timestamps such that it always ran
MakeHeader.py but never used its output, leading to overbuild noise
when running what should be a null 'make'.
- but mostly: it's just an awkward way of dealing with C code.
Seems FreeBSD kernel can spawn both kernel processes (what is what htop currently sees) and kernel threads.
For now let's consider kernel processes kernel "threads".
* size_t nmemb (number of elements) first, then size_t size
* do not assume char is size 1 but use sizeof()
* allocate for char, not pointer to char (found by Michael McConville,
fixes#261)