The review of 6a0f123a found that nvn_submit_prepare took the same handle given twice in one nvnQueueSubmitCommands
call for another thread's submission in flight: the first occurrence takes the copy's busy count from 0 to 1 and
resolves in place, so nvn_copy_enter returns 0 for the second, and unless the copy was known to hold no deferred binds
(deferred 1; it is 0 at the first submission and 2 for any copy with deferred binds) the call cloned it, a malloc and
copy of up to 1-2 MiB and a pin walk under copy_lock shared. It also logged "thread N submits the recording ... while
another thread's submission of it is replayed", the line the play-test reads to tell whether F-2-03's remainder
happens in this game at all, so a call that repeats a handle would have given a false positive. The asynchronous path
already keeps such a repeat in place (nvn_submit_prepare_async: used_at != now).
Now runtime/nvn_submit_guard.h nvn_copy_again says whether the handle came earlier in the same call and resolves in
place there; nvn_submit_prepare asks it only after nvn_copy_enter found the copy busy and the copy may hold deferred
binds, so only that branch pays for the scan. Such an occurrence stays in place and keeps its busy count, which
nvn_submit_done leaves per occurrence as before. Another thread that submits the copy meanwhile still takes a clone.
tests/submit_clone_check gives the copy twice in a quarter of its calls (76,759 repeats kept in place in 800,000 calls,
no replay saw its handles change, the counts end at 0) and checks nvn_copy_again step by step: given twice with
nothing else in flight, in place both times; with another submission in flight, cloned both times.
docs/building.md says so.
Not reproduced before the change. Checks that passed: submit_clone_check, pass_cc_check of nvn_api_cmd.c and
nvn_api_core.c with no new -Wall -Wextra warnings.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
nvnQueueSubmitCommands resolves a copy's deferred binds at the submit call: the handles the game's arrays hold now are
written into the recording copy (nvn_api_cmd.c resolve_deferred). With the replay on the submitting thread, a second
guest thread that submitted the same copy while the first one replayed it, or while the first copied it for a held
continuation (vk_exec.c cont_new), rewrote those handles under that replay: the rest of it bound the next frame's
textures and samplers, and a held continuation could be copied torn (F-2-03's part left after the private copies).
Now each copy counts the synchronous submissions between their prepare and the end of their replay (copy_prefix.busy,
which shares the 8 bytes pins had, so the prefix keeps its 56 bytes). nvn_submit_prepare takes copy_lock shared once
for all handles: the first submission in flight resolves the copy in place, as before; one that finds another in
flight, unless the copy is known to hold no deferred binds, resolves a clone made under that lock, with its texture
pins counted, and nvn_submit_done frees it after the replay, as the asynchronous path does for a copy a queued
submission still reads. A copy the game releases while a submission of it is in flight becomes a zombie and is freed at
the next sweep after it ends (release_copies, zombie_sweep). The bind loop moved unchanged into
runtime/nvn_submit_guard.h (nvn_resolve_binds) so a check can build it; it reports a corrupt record or a call past 16
deep to resolve_deferred, which ends the run with the messages it had, and keeps the first six changes' trace line.
Being code the front end carries under its MIT header, the new header keeps that line and THIRD_PARTY_NOTICES.md's row
names it. A clone is logged the first four times and at each power of two ("submits the recording ... while another
thread's submission of it is replayed"). No timing change and no wait: the clone path runs only when two threads have
one copy in flight at once.
Not reproduced before the change; nobody knows yet whether the game ever submits one copy from two threads at once (the
new line will say). Checks that passed: the new tests/submit_clone_check (four threads submitting two copies 200,000
times each while their arrays change: no replay saw its handles change, both paths ran, the counts ended at 0; the
unguarded 0.10.1 shape through the same harness: about 450,000 of 800,000 replays saw them change; nvn_resolve_binds
step by step), copy_sweep_check (its stand-in prefix follows the new layout), pass_cc_check on every runtime file, no new
-Wall -Wextra warnings in nvn_api_cmd.c and nvn_api_core.c.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
