Files
CelerisLab/docs/compatibility.md
T
ClaudeandClaude Opus 5.5 ddc4a1a6c4 lifecycle: guard Simulation.stream after a failed jet update; scope docs
A set_jet_amplitude failure while creating the internal stream marked the
Simulation failed, but the public stream property still retried
cuda.Stream(). Guard it like the other device-touching methods and add a
regression test (no retry, close still retryable). Lifecycle wording now
names the guarded device-touching methods; cached readers and host staging
stay callable. compatibility.md records the caller-visible fail-closed change.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-28 00:23:56 +00:00

51 lines
2.8 KiB
Markdown

# Compatibility and API changes
Changes that can make a previously accepted setup or call behave differently.
Each entry names the commit, the affected entry points and the observable result.
## 87c3a31: cut-link ownership is validated for every body
`validate_cut_link_ownership` (`body/preprocess/flag_overlay.py`) now runs for
passive bodies as well as Jet/aperture bodies. Every cut link must have an
active fluid receiver (FLUID set, SOLID clear), and each `(receiver, direction)`
population may have only one writer.
Rejected with `ValueError`, before flags, populations or device buffers change:
1. Overlapping or touching passive solids whose cut links write the same
population ("Boundary requires unique cut-link writers").
2. A body whose cut-link receiver is a non-fluid cell, e.g. a channel wall row
or the inlet/outlet column ("Cut links must have active fluid receivers").
Both were previously accepted silently for passive bodies; the interpolated
boundary then had undefined results. The rules apply to the cut links of all
bodies together, so a passive body overlapping a Jet body is rejected as well.
The check runs in `Simulation.initialize`, runtime body sync (`sync_bodies`),
checkpoint save and checkpoint load (`common/checkpoint.py`). Load validates
before restoring anything, so a checkpoint whose saved geometry violates either
rule no longer restores; rebuild the geometry with separated bodies.
## 87c3a31: `Simulation.read_surface_exchange` accepts Jet-driven bodies
`read_surface_exchange(id)` previously required `SurfaceActuation` on the body.
It now also accepts bodies that own Jet aperture links, including Jets with zero
or negative amplitude (the aperture test is geometric). Bodies with neither
`SurfaceActuation` nor aperture links still raise
`ValueError("Body has no surface actuation")`. The value is unchanged: the latest
step's wall/aperture exchange, not total nozzle force.
## 7afb5ad: `Simulation` fails closed after a Jet amplitude device-write failure
`Simulation.set_jet_amplitude` previously only documented that a device error
leaves the per-link velocity column undefined; the instance stayed usable.
Now any error after input validation (internal stream creation or the upload)
marks the Simulation failed. Every later device-touching public method,
including the `stream` property (guard added in the follow-up repair commit on
`claude/jet-update-consistency`), raises
`RuntimeError("Simulation failed (...); close() and recreate it")`. The host
amplitude keeps its previous value. `close()` still works and stays retryable;
cached host readers and host staging calls are not blocked. Invalid input
(`ValueError`/`IndexError`) is unchanged: it raises before any change and the
instance stays usable. `FixedPatchStepper.set_jet_amplitude` already failed the
instance (status `failed`) and is unchanged.