Fix: retire the AICPU loader when a program close's reset also fails

[ChaoWao]

Fixes #2269.

The gap

#2176 made LoadAicpuOp::Finalize() keep its binary handle when rtsBinaryUnload fails, so an owner able to retry the unload survives, and had a program close retire that handle once its device reset completed — the reset ends the generation the handle belonged to.

That covered one of the two reset outcomes. When the reset also failed, the retirement was skipped while the normal tail still cleared device_id_ and device_unusable_:

step	before
first finalize_device	reports the unload error, handle retained
second finalize_device	returns 0 immediately — device_id_ == -1 early-return
destroy_device_context	~LoadAicpuOp issues a second, unreported unload

So the handle was neither retryable nor retired, and the only thing that eventually touched it was a destructor calling into a device whose reset never completed.

Disposition: terminal abandonment

#2269 offered two resolutions. This takes the second — the existing program fatal-teardown style — because the first does not survive contact with the code:

• Leaving device_unusable_ true while clearing device_id_ is inert on teardown: the next finalize() hits if (device_id_ == -1) return 0; and never reaches the fatal branch.
• Keeping device_id_ instead would reach it, but that branch drains and issues aclrtResetDeviceForce — escalating every program soft-reset failure to a force reset, which [Bug] Program loader loses explicit cleanup path when unload and device reset both fail #2269 puts out of scope.
• Either way can_accept_run() would stay false for the runner's life, breaking the init → finalize → init reuse two existing tests rely on.

Terminal abandonment reuses the primitive the fatal path already uses for exactly this condition: abandon_common_after_device_failure() calls ForgetWithoutUnload() because the device's state is unconfirmed and no further runtime call may be issued against it.

What changed

retire_loader_after_device_reset() → retire_loader_after_device_teardown(bool reset_confirmed). Both outcomes forget the handle; only the reason and the diagnostic differ.

	reset confirmed	reset did not complete
what the handle names	a binary that no longer exists	a binary that may still be resident
why forget it	keeps init → finalize → init working	keeps ~LoadAicpuOp from issuing an unload against an unconfirmed device
log level	WARN	ERROR

Neither is a successful release and neither is reported as one — the error the caller already received from that close is the last word.

Kernel retention is untouched, and now enforced rather than argued. A kernel context resets nothing, so its retained handle stays valid and its explicit close is the only thing that may retire it.

Three independent links keep the kernel path clear of this call: a retained handle makes finalize_common() return non-zero; the arch tail returns early on rc != 0 && is_kernel(); and the helper carries an is_kernel() guard. The third is not redundant at the call site, which is not mode-gated — a kernel context with acl_ready_ == false runs neither reset arm and so arrives with reset_completed == false, i.e. the abandon argument, whose job is to forget a handle without unloading it. The call sites say so, naming the guard as the link that does not depend on the early return. This series has produced the same defect three times by applying a shared owner rule to the wrong mode; a comment saying "must not call this" is what failed the last two times.

ForgetWithoutUnload's contract now separates confirmed generation retirement from terminal abandonment, per the issue's last acceptance bullet. The trailing "Only the healthy path reaches here" comment on both arches is corrected too — a failed soft reset lands there as well.

Testing

test_program_loader_double_failure_leaves_nothing_to_unload, parametrized over both reset arms (rt, acl) and both arches.

No reset-failure seam existed: rtDeviceReset and aclrtResetDevice were reachable only through the process-wide, undisarmable arm_acl_guard, which refuses all six ACL/rt symbols at once and exists as the negative assertion for kernel mode. Added arm_reset_failures(count) / reset_call_count() in the shape of arm_unload_failures — fail N, then fall through — checked after the guard so the kernel scenarios are unaffected.

It covers the two soft resets only. aclrtResetDeviceForce stays uninjectable on purpose: it belongs to the fatal branch, which already abandons its bookkeeping and which this change does not touch.

The test then reuses the same context — a second simpler_init → simpler_register_callable → finalize_device, asserting unload_call_count() == 2. That reuse is the stated reason abandonment was chosen over keeping the context poisoned, so it is asserted rather than inferred; two is the double failure's own attempt plus this lifecycle's success, and three would mean the abandoned handle was resurrected into it.

Confirmed failing against the pre-fix code before keeping it, on both arms:

Finalize: rtsBinaryUnload failed: -4321 — loader retains its handle for a close retry
finalize: rtDeviceReset(3) failed during finalize: -4321
Init: LoadAicpuOp::Init: a binary is still loaded; Finalize must retire it first
    assert lib.simpler_init(*init_args) == 0
AssertionError

The barrier lands on the re-init rather than on the destructor assertion, which is the right place: it is the reuse property the disposition was chosen for. The post-destroy assertion still pins that nothing is left for ~LoadAicpuOp.

Gate	Result
a2a3 / a5 / a2a3sim / a5sim builds	pass
C++ unit suite, clean build dir	150 / 150
Python unit suite	2401 passed, 50 skipped
a2a3 onboard, test_kernel_mode_c_api.py -m requires_hardware	16 / 16
a2a3 onboard, tests/st/a2a3/kernel_capture	1 / 1
a2a3 onboard, examples tests/st --platform a2a3	74 PASS / 0 FAIL
clang-format, ruff, ruff format, pyright	clean

The issue's two preservation bullets are covered by tests that were already green and stayed green: test_program_loader_unload_failure_does_not_outlive_its_device (successful reset still reports, still re-inits, still does not unload an old-generation handle) and test_loader_unload_failure_keeps_a_retryable_owner[close_retry|init_rollback] plus test_kernel_lifecycle_retry[*] (kernel ownership, retry, and destroy-refusal unchanged).

a5 runs in CI, not on this box — it is a2a3 and the arch precheck refuses a5. ut-a5 and st-onboard-a5 both passed on the previous head, so the a5 half of the parametrization is executed, just not locally.

st-onboard-a5 first failed on that head with exit 137 (SIGKILL) — killed mid-run, no assertion, no max_diff, no recap — then passed on re-run. That is a different symptom from the TestSdmaAsyncCompletionDemo golden mismatch tracked against #2176, and I am not claiming a shared cause.

Scope

Limited to this owner, its tests and its comments. General reset recovery, faulted-device reinit guarantees, device_unusable_ semantics on the normal tail, pipeline/queue changes, launch support and capture/replay are all out, per the issue.

[coderabbitai]

📝 Walkthrough

Walkthrough

The change retires retained program loader handles after device teardown, even when reset fails. It updates A2/A3 and A5 finalization paths, distinguishes confirmed retirement from terminal abandonment, and adds tests for runtime and ACL reset failures.

Changes

Program loader teardown

Layer / File(s)	Summary
Loader retirement transition src/common/platform/onboard/host/device_runner_base.h, src/common/aicpu_loader/host/load_aicpu_op.h	The retirement helper now accepts the reset result, abandons retained handles without unloading them, and logs confirmed or unconfirmed teardown separately. The related comment distinguishes confirmed retirement from terminal abandonment.
Finalize integration src/a2a3/platform/onboard/host/device_runner.cpp, src/a5/platform/onboard/host/device_runner.cpp	Both finalization paths call loader retirement after teardown regardless of reset success.
Double-failure validation tests/ut/py/kernel_close_faults.cpp, tests/ut/py/test_kernel_mode_c_api.py	The test stubs inject bounded reset failures. Tests cover unload plus runtime or ACL reset failure, repeated finalization, and destruction without another unload.

Priority: ➖ Normal

Estimated code review effort: 3 (Moderate) | ~25 minutes

Change: Bug fix · Severity of issue fixed: Medium

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 40.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 20 functions across 6 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The changes satisfy the coding requirements in [#2269]. Program-mode finalization now retires the retained loader after both reset outcomes. Confirmed reset uses retirement semantics, and failed reset…
Out of Scope Changes check	✅ Passed	The changed files are limited to the AICPU loader teardown owner, its related declaration and comments, and fault-injection tests. The changes do not introduce general reset recovery or unrelated pipe…
Title check	✅ Passed	The title clearly and concisely describes the main change: retiring the AICPU loader when a program close also fails during reset.
Description check	✅ Passed	The description directly explains the teardown gap, the terminal-abandonment fix, kernel-mode preservation, test coverage, validation results, and scope.

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_{A rabbit watched the loader close,
When reset failed, it chose repose.
The handle left the runtime trail,
No second unload chased its tail.
Both reset paths now pass the test.
The teardown burrow rests at last.}

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[coderabbitai]

Actionable comments posted: 1

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only still-valid issues, skip the rest with a brief reason, keep changes
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Inline comments:
In `@src/a2a3/platform/onboard/host/device_runner.cpp`:
- Line 1158: Update the stale reset comments in finalize() so they state that
the loader handle is forgotten regardless of reset outcome, matching the
unconditional retire_loader_after_device_teardown call and the newer comment
below it. Apply the same wording correction in
src/a2a3/platform/onboard/host/device_runner.cpp at lines 1158-1158 and
src/a5/platform/onboard/host/device_runner.cpp at lines 1012-1012; both sites
require the comment change.

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Reviewing files that changed from the base of the PR and between fd5f2d9 and 84709c8.

📒 Files selected for processing (6)

• src/a2a3/platform/onboard/host/device_runner.cpp
• src/a5/platform/onboard/host/device_runner.cpp
• src/common/aicpu_loader/host/load_aicpu_op.h
• src/common/platform/onboard/host/device_runner_base.h
• tests/ut/py/kernel_close_faults.cpp
• tests/ut/py/test_kernel_mode_c_api.py

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[ChaoWao]

Addressed all three at 085fff5e0, also rebased onto d0ed672d5 (main moved).

The stale comment — same defect class this PR fixes

You and CodeRabbit landed on the same thing, and it was mine: I left the comment describing the old if (reset_completed) behaviour in front of the new unconditional call, so it claimed the handle is retained on failure while the code forgets it. Replaced verbatim with your text on both arches. What can outlive a failed reset is the device-side binary, not the host handle — which is what terminal abandonment means. Dropped "existing isolation policy" too, since it implied the handle was parked somewhere awaiting recovery.

1. The guard carries more weight at the call site than the helper's doc admitted

You are right, and the doc understated it by calling the guard redundant. The chain I leaned on has three independent links, and the call site is where that stops being obvious:

link	what it does
a retained handle makes finalize_common() return non-zero	so rc != 0
the arch tail returns early on rc != 0 && is_kernel()	so a kernel close never reaches the reset block
the helper's is_kernel() guard	inert even if it did

The call site is not mode-gated, so a kernel context with acl_ready_ == false runs neither reset arm and arrives with reset_completed == false — the abandon argument, whose whole job is to forget a handle without unloading it. A reader there has to go find the helper to learn that is inert. Added the sentence at both call sites, naming the latch guard as the link that does not depend on the early return.

2. The disposition's own reason was untested

This is the better of the two findings. Abandonment was chosen because keeping device_unusable_ would break init → finalize → init, and the test stopped at destroy_device_context — so the reuse claim rested on the confirmed-reset tests, which exercise the arm this PR does not change. Circular.

Appended the second lifecycle inside the same context: simpler_init → simpler_register_callable → finalize_device → unload_call_count() == 2. Two is the double failure's own attempt plus this lifecycle's success; three would mean the abandoned handle was resurrected into it.

It moved the barrier to the right place. Pre-fix, the test now stops here rather than at the destructor assertion:

assert lib.simpler_init(*init_args) == 0
Init: LoadAicpuOp::Init: a binary is still loaded; Finalize must retire it first

That is the stated reason for the disposition, now failing when the disposition is absent. The post-destroy assertion still pins "nothing left for ~LoadAicpuOp", at 2 instead of 1.

3. Nit: aclrtResetDeviceForce

Correct that arm_reset_failures otherwise reads as covering every reset. It covers the two soft resets only; the force reset belongs to the fatal branch, which already abandons and which this change does not touch. Said so in the test docstring, the shim comment, the commit message and the PR body.

Verification at 085fff5e0

Gate	Result
a2a3 / a5 / a2a3sim / a5sim builds	pass
C++ unit suite, clean build dir	150 / 150
Python unit suite	2401 passed, 50 skipped
a2a3 onboard, test_kernel_mode_c_api.py -m requires_hardware	16 / 16
a2a3 onboard, tests/st/a2a3/kernel_capture	1 / 1
a2a3 onboard, examples tests/st --platform a2a3	74 PASS / 0 FAIL
clang-format, ruff, ruff format, pyright	clean

CI on the previous head finished 19 pass / 1 skip — including ut-a5, which runs the a5 half of this test's parametrization, and st-onboard-a5. So a5 is no longer compile-verified only; the PR body said otherwise and is updated.

One thing worth recording rather than glossing: st-onboard-a5 first failed on that head with exit 137 (SIGKILL) — killed mid-run, no assertion, no max_diff, no recap — which is a different symptom from the TestSdmaAsyncCompletionDemo golden mismatch tracked on #2176. It passed on re-run. I am not claiming the two share a cause.