It now takes a context pointer (opaque data) that holds the buffers it
uses for the temporary strings. If the context pointer is null, a static
context is used (making those uses of va NOT thread-safe). Most calls to
va use the static context, but all such calls have been formatted
consistently so they are easy to find when it comes time to do a full
audit.
The way I wound up using the field meant that exprctx should not "own"
the hashlinks chain, but rather just point to it. This fixes the nasty
access errors I had.
I want to be able to use name references, but that requires string
items, so anything that would normally be dictionary or array (or
binary, even) would also need to accept string. This seemed to be the
cleanest solution. Any custom parser would then need to check the type
and act appropriately, but any inappropriate types have already been
pre-filtered by the standard parsers.
Care needs to be taken to ensure the right function is used with the
right arguments, but with these, the need to use qconj(d|f) for a
one-off inverse rotation is removed.
I forgot to right-shift the value so offsets were becoming 0 or 8
instead of 0-15. This fixes the management of small objects. It turns
out that after this fix, qfvis's problems were caused by fragmentation
in the windings. Need to revisit line allocation and use POT-specialized
pools.
I think the sub-line allocator falling over is the final source of
qfvis's leaks. It certainly causes a mess of the sub-lines. But having
some tests to get working sure beats scratching my head over qfvis :)
They're binned by powers of two (with in between sizes going to the
smaller bin should I make cache-line allocations NPOT (which I think
might be worthwhile). However, there seems to still be a bug somewhere
causing a nasty leak as now my hacked qfvis consumes 40G in less than a
minute.
The idea is to not search through blocks for an available allocation.
While the goal was to speed up allocation of cache lines of varying
cluster sizes, it's not enough due to fragmentation.
They take advantage of gcc's vector_size attribute and so only cross,
dot, qmul, qvmul and qrot (create rotation quaternion from two vectors)
are needed at this stage as basic (per-component) math is supported
natively by gcc.
The provided functions work on horizontal (array-of-structs) data, ie a
vec4d_t or vec4f_t represents a single vector, or traditional vector
layout. Vertical layout (struct-of-arrays) does not need any special
functions as the regular math can be used to operate on four vectors at
a time.
Functions are provided for loading a vec4 from a vec3 (4th element set
to 0) and storing a vec4 into a vec3 (discarding the 4th element).
With this, QF will require AVX2 support (needed for vec4d_t). Without
support for doubles, SSE is possible, but may not be worthwhile for
horizontal data.
Fused-multiply-add is NOT used because it alters the results between
unoptimized and optimized code, resulting in -mfma really meaning
-mfast-math-anyway. I really do not want to have to debug issues that
occur only in optimized code.
The problem is that I needed to support dynamic types on operators (for
bit-field enums), had things working, but a bad edit messed things up
and I had to rebuild that bit of code. Missed one bit :P
It is capable of parsing single expressions with fairly simple
operations. It current supports ints, enums, cvars and (external) data
structs. It is also thread-safe (in theory, needs proper testing) and
the memory it uses can be mass-freed.
This was inspired by
Hoard: A Scalable Memory Allocator
for Multithreaded Applications
Emery D. Berger, Kathryn S. McKinley, Robert D. Blumofe, Paul R.
Wilson,
It's not anywhere near the same implementation, but it did take a few
basic concepts. The idea is twofold:
1) A pool of memory from which blocks can be allocated and then freed
en-mass and is fairly efficient for small (4-16 byte) blocks
2) Tread safety for use with the Vulkan renderer (and any other
multi-threaded tasks).
However, based on the Hoard paper, small allocations are cache-line
aligned. On top of that, larger allocations are page aligned.
I suspect it would help qfvis somewhat if I ever get around to tweaking
qfvis to use cmem.
The calculation fails (produces NaN) if the vectors are anti-parallel,
but works for all other combinations. I came up with this implementation
when I discovered Unity's Quaternion.FromToRotation could did not work
with very small angles. This implementation will produce a usable
quaternion below 0.00255 degrees (though it will be slightly larger than
unit). Unity's failed such that I could see KSP's skybox snap while it
rotated around my test vessel.
The array has to be allocated using byte elements and thus the size of
the array is the number of bytes, but it needs to be the actual number
of elements in the array. Problem caused by not knowing the actual type
(and C not having type variables anyway).
