feat: reclaim fiber + async heap (close the closure-env / Future leaks)

Browse Source

Closes the documented per-spawn closure-env leak and most of the async leak,
using only the existing closure.env / closure.fn_ptr field accessors — no compiler
change. Also names the fat-pointer ABI in core.sx (ClosureRaw / SliceRaw) so the
underlying {fn_ptr, env} / {ptr, len} layout is discoverable in one place.

- Fiber body env: Scheduler.reap_fiber frees f.body.env via f.dctx.allocator (the
  spawn-time allocator snapshotted in dctx) at all three reap sites (run/poll/
  deinit). 1820's 'live after deinit' 3 -> 0.
- Async box + closure envs: sx_run_boxed_closure frees the ThunkBox, the
  completion-closure env, and the worker's env (new ThunkBox.worker_env) the
  instant the worker completes.
- Async Future: two-flag ownership — Future.worker_done (set at the end of the
  completion closure) + consumed (set at the end of await); fut_release frees the
  heap Future (via the captured Future.alloc) when BOTH are set, so the LAST of
  {worker, await} reclaims it. await now CONSUMES the future (single-use; touching
  it afterward is a use-after-free — documented). Residual for an AWAITED future
  is 0 (lock: examples/concurrency/1827); a never-awaited future (fire-and-forget /
  race loser) keeps only its Future struct — the structured-concurrency remainder.

Self-reviewed across orderings (await-after/before-complete, cancel-then-await,
cancel-while-parked, double-free via await+deinit, race residual, blocking impl,
cross-allocator reap) — all deterministic, no UAF/double-free. Suite 855/0;
byte-identical on aarch64-macOS + aarch64-linux; .ir churn is the core.sx +
Future/ThunkBox field additions.

...

This commit is contained in:

agra

2026-06-28 16:19:04 +03:00

parent aae7d72a66

commit 2b1307a0dc

52 changed files with 168342 additions and 160106 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download Patch File Download Diff File Expand all files Collapse all files

8149

examples/protocols/expected/0400-protocols-impl-for-builtin.ir

File diff suppressed because one or more lines are too long

8579

examples/protocols/expected/0413-protocols-parameterized-protocol-value.ir

File diff suppressed because one or more lines are too long

8893

examples/protocols/expected/0414-protocols-generic-struct-protocol-erase.ir

File diff suppressed because one or more lines are too long

8911

examples/protocols/expected/0416-protocols-auto-type-erasure.ir

File diff suppressed because one or more lines are too long