A hitch on the render side never showed in a report: the client report lists slow client frames
only, and a present sample had no frames at all. While a present sample runs, the present hook
notes when each frame is presented; the report then lists the longest gaps between presents, each
with what the present thread's samples in it spent their time in and how many were waiting. This
is what found a 170 ms stall every 5 s: the game's batched GPU uploads blocking in the driver.
Players reported the game hanging for about a second while skating. A
profile showed the memory line in the log walking every heap
(HeapSummary) on the client thread, 0.5 to 2 s every two minutes. An
audit of everything that runs on the game's update and render threads
found more of the same, and Sentry's top crashes had causes of ours.
Freezes:
- Memory log line: no heap walk or thread snapshot; the GPU part and the
write happen on a thread of their own.
- Profile database: synchronous=NORMAL in WAL mode. A save is still kept
when the game crashes; every play event no longer waits for the disk
inside the game's hooks.
- ReSkate's own preferences and values (menu clicks, session sliders,
Discord) are saved by a background writer in order; reads see a value
until it is saved.
- Input: the foreground window and the keyboard are sampled on a thread
of their own (GetAncestor and GetAsyncKeyState stalled the client tick
40-50 ms when another program held Windows' lock); flight input uses
the sample; ClipCursor at most twice a second while a menu has the
pointer.
- Hooks installed while the game runs go in one transaction per place
(HookBatch): throwdowns, remote players, the party, Hall of Meat.
- Off the update thread: the host's map package lookup (one table read in
the background, not the Mods folder per offer), the trainer's map file
and settings save, Board Break's settings save, mod music playlists and
their covers, the Spotify station covers.
- Off the render thread: the Modding page's and the deck card's Mods
folder reads. The overlay's three startup waits share five seconds.
- Less work per frame: Steam names reused while one a frame is asked
again, 2 friends a tick, steam_api64.dll checked once per process,
cosmetic names read in place rather than a system call per character,
an outfit load no longer copies the inventory per slot, the throwdown
type scan runs at background priority over resident memory, the Board
Break deck label is kept a minute.
Crashes:
- Render-resource pool: the metadata fields are written to the state
owner only. The other renderer is 0x2daa00 bytes, and +0x11aae28 is far
past its end (store_field crash; heap corruption in every release).
- Other players' skateboard effects: a stale skateboard component is no
longer followed, and the joint lookup is walked with a bound first (an
endless loop in reused memory ended in GameStall).
- Launcher: Oodle decodes into the buffer it asks for with corrupt data
possible, and its assertions no longer stop the process (heap corruption
in the store-copy scan; a breakpoint in oo2core).
Timings (Send performance timings):
- A frame of half a second or more in a level is sent as game.freeze:
where the time went (ReSkate's tick, the game's frame, or outside it),
whether the renderer kept presenting, and ReSkate's busiest zones.
- Closing the game sends the level session it was in.
Music after a connection drop:
- Spotify device: an account Spotify could not be reached with is kept and
tried again (3 s doubling to a minute); a session that drops is taken
up again. Only an account Spotify refuses is asked for anew.
- YouTube playlist pictures that could not be fetched are tried again,
from 30 s to 10 minutes apart.
A 30 s profile on a 77-player server had four frames of 20 to 30 ms against a
usual 7.8 ms, from two things:
- The Park Editor read every mod's manifest every five seconds to list park
mods, on the game's thread and whether or not its list was showing (the
switch for that is never set): about 11 ms each time. The look every few
seconds now runs on a thread of its own and is taken up when it is done;
the one after making, renaming or removing a park is still at once.
- Connecting to a player asked Steam for their name, and waited on the Steam
client for 7 to 10 ms each time a player came into reach. The link takes
the name already read, if any: it only labels the link in diagnostics.
Profiler: a release ReSkate.dll has no symbols, and its functions were all
named after the nearest export. The check for that looked at the symbol's
size, but DbgHelp gives an export a size up to the next one. It now asks
whether the module's own symbols were loaded, and writes ReSkate.dll+0x<offset>
when they were not, to be named from the release's symbols afterwards
Replay drafts: the replay editor saves a draft as a pin on the recording
and a thumbnail in the game's media catalogue, which the Drafts screen
lists from. The game only makes that catalogue for a user signed in to
its backend, so under ReSkate a saved draft had nowhere to be listed.
ReSkate now registers the catalogue service and signs in a local user,
both with the game's own functions, so the game's Drafts screen works as
it was built: save, list, open and delete within a session.
A draft's footage stays in the recorder's memory, as it does in the
game, and does not outlive the session. Thumbnails of earlier sessions'
drafts are removed from the catalogue folder at startup; only folders
whose manifest is a replay draft's are touched.
Profiler: `perf sample` on the client thread now reports the slowest
client frames ahead of the function table, each with what it spent its
time in. An average over thirty seconds hides a single long frame.
Game
- Player distance (Settings > Interface, "player-distance"): how far
away another player is still built as a skater, 50 to 1000 m, default
120. Past it they keep their nametag or dot. All the way up shows
everyone. A player already shown stays until 15% further out, so one
skating along the edge is not built and taken down over and over. The
game ran a full skater for every player on the server wherever they
were, which is most of a frame on a full one
- Nametags are always ReSkate's own. The "ReSkate nametags" toggle, the
"Nametag style" button and the nametag-style command are gone; the
game's own nametags are never shown
- Nametag distance ("nametag-distance"): how far away a name still
shows before it becomes a dot, 10 to 500 m. Default 120, was a fixed
150, so by default the name and the skater go at the same distance
- Nametag dots ("nametag-dots"): off hides the dots for far players and
the ones at the screen's edge for players off screen
- Friends' nametags only ("nametags-friends"): only Steam friends get a
name or dot; chat bubbles still show for everyone
Server
- A player out of sight of another (half as far again as the low rate
starts, 255 m by default) is sent to them once a second instead of
five times. On a full server most players are out of each other's
sight, and at five a second each they were most of what was sent
- Rotations are rounded before a pose is passed on, more coarsely the
further away the recipient is: 0.04 degrees within the full rate's
reach, 0.16 within the half rate's, a third of a degree past that,
about 5 degrees out of sight. The pose is still an ordinary one. A
bone that turned by less than a step is the same bytes as before, so
the difference from the reference leaves it out, and the low bits of
the ones that did turn pack away. By distance only: a player the
crowd limit slowed keeps the fine rotations
- A recipient crossing from one precision to another is sent a whole
state of that player, since a difference from a reference of another
precision would carry every bone again
- "net" shows the size of the poses sent at each precision
Profiler
- A function in ReSkate.dll is reported by its address when the DLL has
no symbols. A release build named every one of ours as the nearest of
three exports, so a report could not say which was slow; the
release's symbols name the address afterwards
AyeZeeBB