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.
