Just head and tail are atomic, but it seems to work nicely (at least on
intel). I actually had more trouble with gcc (due to accidentally
testing lock-free with the wrong ring buffer... oops, but yup, gcc will
happily optimize your loop to spin really really fast). Also served as a
nice test for C11 threading.
Because the calculation didn't take the hunk header size (which is not
included in the hunk size) into account, the conversion to MB was one
short and thus the rounding up to the next 8 MB boundary was giving the
current total hunk size (ie, the already given size). Most confusing to
a user ("But I already asked for 128MB!").
It turns out that copying just "unknown" is a significant performance
hit when doing over 100M allocations. Making Hunk_RawAlloc the core and
initializing the name field with a single 0 shaved about a second off
`qfvis gmsp3v2.bsp` (from about 39s to about 38s).
My reason for using Hunk_HighAlloc for allocating cache blocks was to
lock them down so they were safe for the sound mixer to access when
running in a real-time thread. However, I had never tested under tight
memory constraints, which proved that the design (or maybe just
implementation) just wasn't robust. However, now that sounds are loaded
into a completely separate region, it's safe to put the cache back to
its original behaviour (still with 64-byte alignment and such, of
course). This will even allow the high hunk to be used again, though it
effectively was anyway with Hunk_TempAlloc.
Getting the tag is possibly useful in general and definitely in
debugging. Setting, I'm not so sure as it should be done when allocated,
but that's not always possible.
Also, correct the return type of z_block_size, though it affected only
Z_Print. While an allocation larger than 4GB is... big for zone, the
blocks do support it, so printing should too.
Since Ruamoko got vector types, zone's 8-byte alignment was no longer
sufficient due to hardware-enforced alignment requirements of the
underlying vector operations.
Fixes#28.
And use it for Ruamoko object reference counts.
I need reference counts for dealing with block sound buffers since they
can be shared by many channels. I figured I take care of Ruamoko's
reference count location at the same time.
Fixes#27.
The tests fail as they exercise how the cache *SHOULD* work rather than
how it does now.
The tests do currently pass for the pending work I've done on the cache
system, but while working on it, I remembered why I reworked cache
allocation...
The essential problem is that sounds are loaded into the cache, which is
fine for synchronous output targets, but has proven to be a minefield
for asynchronous output targets (JACK, ALSA).
The reason for the minefield is the hunk takes priority over the cache,
and is free to move cache blocks around, and *even dispose of them
entirely* in order to satisfy memory allocations from either end of the
hunk. Doing this in an entirely single-threaded process (as DOS Quake
was) is perfectly safe, as the users of the cache just reload the
pointer each time, and bail if it's null (meaning the block has been
freed), or even cause the data to be reloaded if possible (I'm a little
fuzzy on the details for that as I didn't write that code). However, in
multi-threaded code, especially real-time (JACK, possibly ALSA), it's a
recipe for disaster. The 4cab5b90e6 commit was a (mostly) successful
attempt to mitigate the problem by allocating the cache blocks from the
high-hunk (thus minimizing any movement caused by low-hunk allocations),
it resulted in cache allocates and regular high-hunk allocations somehow
getting intertwined: while investigating just how much memory ad_tears
needs (somewhere between 192MB and 256MB), I got "trashed sentinel"
errors and upon investigation, I found what looks very suspiciously like
audio data written across a hunk control block.
I've decided that the cache allocation *algorithm* should be reverted to
how it was originally designed by Id (details will remain "modern"), but
while working on the tests, I remembered why I had done the changes in
the first place (above story). Thus the work on reverting the cache
allocation can't go in until I get sound memory management independent
of the cache. The tests are going in now so I have a constant reminder :)
And make Sys_MaskPrintf take the developer enum rather than just a raw
int.
It was actually getting some nasty hunk corruption errors when under
memory pressure that made it clear the sound system needs some work.
The main goal was to get visframe out of mnode_t to make it thread-safe
(each thread can have its own visframe array), but moving the plane info
into mnode_t made for better data access patters when traversing the bsp
tree as the plane is right there with the child indices. Nicely, the
size of mnode_t is the same as before (64 bytes due to alignment), with
4 bytes wasted.
Performance-wise, there seems to be very little difference. Maybe
slightly slower.
The unfortunate thing about the change is the plane distance is negated,
possibly leading to some confusion, particularly since the box and
sphere culling functions were affected. However, this is so point-plane
distance calculations can be done with a single 4d dot product.
This ensures that the plugin's shutdown function won't get called twice
in the event of an error in the plugin's unload sequence triggering a
second Sys_Shutdown, especially if the plugin is being unloaded as a
part of another sub-system's shutdown sequence (which is probably in
itself a design mistake, need to look into that).
They're really redundant, and removing the next pointer makes for a
slightly smaller cvar struct. Cvar_Select was added to allow finding
lists of matching cvars.
The tab-completion and config saving code was reworked to use the hash
table DO functions. Comments removed since the code was completely
rewritten, but still many thanks to EvilTypeGuy and Fett.
Hash_Select returns a list of elements that match a given criterion
(select callback returning non-0).
Hash_ForEach simply calls a function for every element.
Other parts of quakefs treat an empty path as an error, so fs_sharepath
and fs_userpath must never be empty or they will effectively be
rejected. While the user explicitly setting them to empty strings is one
way for them to become empty, another is QFS_CompressPath compressing
'.' to an empty path, which makes it rather difficult to set up the
traditional quake directory tree (ie, operate from the current
directory).
This is an extremely extensive patch as it hits every cvar, and every
usage of the cvars. Cvars no longer store the value they control,
instead, they use a cexpr value object to reference the value and
specify the value's type (currently, a null type is used for strings).
Non-string cvars are passed through cexpr, allowing expressions in the
cvars' settings. Also, cvars have returned to an enhanced version of the
original (id quake) registration scheme.
As a minor benefit, relevant code having direct access to the
cvar-controlled variables is probably a slight optimization as it
removed a pointer dereference, and the variables can be located for data
locality.
The static cvar descriptors are made private as an additional safety
layer, though there's nothing stopping external modification via
Cvar_FindVar (which is needed for adding listeners).
While not used yet (partly due to working out the design), cvars can
have a validation function.
Registering a cvar allows a primary listener (and its data) to be
specified: it will always be called first when the cvar is modified. The
combination of proper listeners and direct access to the controlled
variable greatly simplifies the more complex cvar interactions as much
less null checking is required, and there's no need for one cvar's
callback to call another's.
nq-x11 is known to work at least well enough for the demos. More testing
will come.
The prefix gives more context to the error messages, making the system a
lot easier to use (it was especially helpful when getting my cvar revamp
into shape).
Based on the flags type used in vkparse (difference is the lack of
support for plists). Having this will make supporting named flags in
cvars much easier (though setting up the enum type is a bit of a chore).
This allows for easy (and safe) printing of cexpr values where the type
supports it. Types that don't support printing would be due to being too
complex or possibly write-only (eg, password strings, when strings are
supported directly).
QFS_NextFilename was renamed to QFS_NextFile to reflect the fact it now
returns a QFile pointer for the newly created file (as well as the
name). This necessitated updating WritePNG to take a file pointer
instead of a file name, with the advantage that WritePNGqfs is no longer
necessary and callers have much more control over the creation of the
file.
This makes QFS_NextFile much more secure against file system race
conditions and attacks (at least in theory). If nothing else, it will
make it more robust in a multi-threaded environment.
It's not there yet as it promptly closes the file and returns only the
filename (and then only the portion within the user's directory tree).
However, this worked nicely as a test for Sys_UniqueFile.
QF currently uses unique file names for screenshots and server-side
demos (and remote snapshots), but they're generally useful.
QFS_NextFilename has been filling this role, but it is highly insecure
in its current implementation. This is the first step to taking care of
that.
clang doesn't like anything but a bare 0 as null (and in some of the
cases, it was quite right: '\0' should not be treated as a null
pointer). And the crashers were just for paranoia and probably aren't
needed any more (kept for now, though).
They're still slightly confusing, but the situation itself is confusing,
but the comments should be a little more helpful now as they are more
explicit about the orientation of the matrices and just which axis
points where.
I finally spent the time to work out what it was trying to say. Still
not sure it's clear, but what is clear is that there was probably some
disagreement at Id about the orientation of the world.
Since Z_Malloc uses Z_TagMalloc to do the work, this ensures the check
is always run.
Also, add the check to Z_Realloc when it needs to adjust an existing
block.
Just 32-bit rounding to next higher power of two, and base 2 logarithm.
Most importantly, they are suitable for use in initializers as they are
constant in, constant out.
And add a unary op macro. Having VectorCompOp makes it easy to write
macros that work for multiple data widths, which is why it and its users
now use (dst, ...) instead of (..., dst) as in the past. I'll sort out
the other macros later now that I know the compiler handily gives
messages about the switched order (uninitialized vars etc).
For int, long, float and double. I've been meaning to add them for a
while, and they're part of the new Ruamoko instructions set (which is
progressing nicely).
Forgetting to unhook the functions (Sys_Printf and the client console's
input event handler) was not a problem for static builds because the
functions were always present, but in builds with dynamic plugins, the
client console's code got ripped away and thus Sys_Printf and the event
hander were being sent into invalid memory. Too much work, not enough
play (with a fully installed client).
The homogeneous coord was not being initialized and thus was picking up
rubbish from the stack. This is why the test would succeed in some
circumstances but fail in others.
mtwist_rand_0_1 produces numbers in the range [0, 1) and
mtwist_rand_m1_1 produces numbers in the range (-1, 1). The numbers will
not be denormal, so the distribution should be fairly uniform (as much
as Mersenne Twister itself is), but this needs proper testing.
0 is included for the mtwist_rand_0_1 as it seems useful, but -1 is not
included in mtwist_rand_m1_1 in order to keep the extremes of the
distribution balanced around 0.
The cache system pointers are now indices into an array of
cache_system_t blocks, allowing them to be 32 bits instead of 64, thus
allowing cache_system_t to fit into a single CPU cache line. This still
gives and effective 38 bits (256GB) of addressing for cache/hunk. This
does mean that the cache functions cannot work with more than 256GB, but
should that become a problem, cache and working hunking hunk can be
separate, and it should be possible to have multiple cache systems.
There's no point in zeroing out memory that is only going to be
overwritten by the loaded file (excess bytes beyond the end of a
massaged text file shouldn't be accessed anyway, and the terminating
null is still written).
This is needed for cleaning up excess memsets when loading files because
Hunk_RawAllocName has nonnull on its hunk pointer (as the rest of the
hunk functions really should, but not just yet).
In trying to reduce unnecessary memsets when loading files, I found that
Hunk_RawAllocName already had nonnull on it, so quakefs needed to know
the hunk it was to use. It seemed much better to to go this way (first
step in what is likely to be a lengthy process) than backtracking a
little and removing the nonnull attribute.
This allows using references in expressions, eg:
$frames.size * size_t($properties.limits.maxSamplers)
As references remain property list items until actually evaluated.
For now, just dot product, trig, and min/max/bound, but it works well as
a proof of concept. The main goal was actually min. Only the list of
symbols is provided, it is the user's responsibility to set up the
symbol table and context.
cexpr's symbol tables currently aren't readily extended, and dynamic
scoping is usually a good thing anyway. The chain of contexts is walked
when a symbol is not found in the current context's symtab, but minor
efforts are made to avoid checking the same symtab twice (usually cased
by cloning a context but not updating the symtab).
The generated short names for a lot of Vulkan enums start with a number
(eg VK_IMAGE_TYPE_2D -> 2d). Having to prefix the short name with ` is a
tiny cost for the convenience.
While there may be better solutions, I needed a varargs function for
building Vulkan specialization data. Like progs functions, negative
parameter counts indicate ellipsis with the number of fixed parameters
being equal to -param_count - 1.
I'm not sure what I was thinking when I made PL_RemoveObjectForKey take
a const plitem. One of those times where C could do with being a little
more strict.
Listeners are separate to the main callback as listeners have only
read-only access to the objects, but the main callback is free to modify
the cvar and thus can act as a parser and validator. The listeners are
invoked after the main callback if the cvar is modified. There does not
need to be a main callback for the listeners to be invoked.
I decided cvars and input buttons/axes need listeners so any changes to
them can be propagated. This will make using cvars in bindings feasible
and I have an idea for automatic imt switching that would benefit from
listeners attached to buttons and cvars.
I didn't notice that uint is defined somewhere on Linux... until I tried
compiling for windows (not defined). Use a define to keep the cast
function naming nice.
It turns out that calling Sys_Shutdown in the signal handler can cause
lockups due to the signal occurring at unsafe times. Fortunately, this is
just the IO related signals (INT, HUP, TERM, QUIT) as the others are
usually caused by actual errors and should not occur in system code thus
timing should not be an issue. However, care will need to be taken when it
comes to handling SIGINT or similar for breaking runaway progs code when
that time comes.
While QF doesn't currently use nanoseconds, having access to a clock
that is not affected by setting system time is nice, and as a bonus, can
handle suspends should the need arise.
At the low level, only unions can cause a set to grow. Of course, things
get interesting at the higher level when infinite (inverted) sets are
mixed in.
Instead of printing every representable member of an infinite set (ie,
up to element 63 in a set that can hold 64 elements), only those
elements up to one after the last non-member are listed. For example,
{...} - {2 3} -> {0 1 4 ...}
This makes reading (and testing!) infinite sets much easier.
Most of the set ops were always endian-agnostic since they were simply
operating on multiple bits in parallel, but individual element
add/remove/test was very endian-dependent. For the most part, this
didn't matter, but it does matter very much when loading external data
into a set or writing the data out (eg, for PVS).
