Refactor: decouple logger SO + collapse simpler_init/bind_executors → device_init

[ChaoWao]

Summary

Continues the API-narrowing theme of #723. Two strands woven together — both
amount to "one piece of state lives in one place; no redundant C-ABI
plumbing".

(1) Logger ownership moves entirely to libsimpler_log.so

Before: simpler_init lived on host_runtime.so but reached cross-SO into
libsimpler_log.so to mutate HostLogger, then cached log_level /
log_info_v on every DeviceRunner so run_runtime could forward them to
AICPU via KernelArgs. Log state lived in three places (HostLogger, runner
member, KernelArgs) all seeded off the same C-ABI argument.

After: libsimpler_log.so exports its own simpler_log_init(level, info_v) C entry, called from ChipWorker::init before host_runtime.so
is even dlopen'd. HostLogger gains level()/info_v() raw getters.
Every consumer (host_runtime populating KernelArgs, AICPU sim SO setters,
onboard CANN dlog sync) reads HostLogger::get_instance() directly. Log
state lives in exactly one place; no log argument ever travels through
the host_runtime.so C ABI.

(2) host_runtime.so's init surface collapses to one entry: device_init

Before: simpler_init(ctx, device_id, log_level, log_info_v) +
bind_executors(ctx, aicpu_*, aicore_*) — two adjacent init-time entries
always called back-to-back.

After: device_init(ctx, device_id, aicpu_*, aicore_*) — single entry
that attaches the calling thread, takes ownership of executor binaries, and
(onboard) syncs CANN dlog from HostLogger. Log args gone because (1) put
them on a separate SO.

What changed

File group	Change
libsimpler_log.so (src/common/log/host_log.{h,cpp})	HostLogger::level() / info_v() getters; new simpler_log_init(int, int) C export
pto_runtime_c_api.h	simpler_init + bind_executors removed; new device_init(ctx, device_id, aicpu_*, aicore_*); dlsym list updated
4 × pto_runtime_c_api.cpp	Replace old entries with single device_init; onboard's dlog_setlevel reads HostLogger::get_instance().level()
4 × DeviceRunner.{h,cpp}	Drop log_level_ / log_info_v_ members + set_log_level / set_log_info_v setters; run() reads HostLogger::get_instance() directly
ChipWorker.{h,cpp}	dlsym simpler_log_init from libsimpler_log.so, call it before host_runtime.so dlopen; replace simpler_init_fn_ + bind_executors_fn_ with single device_init_fn_; one rc check + one rollback
Docs	chip-level-arch.md, dynamic-linking.md, logging.md, testing.md, python/simpler/{__init__.py,_log.py}, worker_malloc/README.md all refreshed

End-state diagram

libsimpler_log.so      ← single owner of log state
├── simpler_log_init(level, info_v)            ← only writer
└── HostLogger::get_instance().level()/.info_v() ← anyone can read

host_runtime.so       ← log args gone from every entry
├── create_device_context()
├── device_init(ctx, device_id, aicpu_*, aicore_*)
│   ├── attach_current_thread(device_id)
│   ├── set_executors(move aicpu, move aicore)
│   └── (onboard) dlog_setlevel(-1, HostLogger::get_instance().level(), 0)
├── run_runtime(ctx, runtime, callable, args, block_dim, aicpu_thread_num,
│               enable_l2_swimlane, enable_dump_tensor, enable_pmu, output_prefix)
│   └── KernelArgs.log_level = HostLogger::get_instance().level();
├── finalize_device(ctx) / destroy_device_context(ctx)
└── (ACL / comm extension surface, unchanged)

Test plan

• pip install --no-build-isolation -e . — all 4 host_runtime.so + libsimpler_log compile clean on macOS (a2a3sim + a5sim)
• pytest tests/ut/py — 116 passed, 7 skipped (unrelated torch-gated)
• examples/workers/l2/{hello_worker, worker_malloc}/main.py on a2a3sim + a5sim
• tests/ut/py/test_worker/test_bootstrap_context_sim.py (5 passed, exercises init → device_init → run end-to-end on sim)
• Onboard CI: ut-a2a3 / ut-a5 / st-onboard-* (Linux + hardware)
• ctest --test-dir build/ut_cpp (Linux)

[gemini-code-assist]

Code Review

This pull request refactors the PTO Runtime to move the binding of AICPU and AICore executor binaries from a per-run operation to a one-time initialization step. It introduces a new bind_executors C-API and updates the DeviceRunner class to store these binaries as members, significantly simplifying the run method signatures across all supported platforms. Feedback focuses on ensuring the documentation accurately reflects the simulation platform's binary loading lifecycle and addressing a potential resource leak in the initialization path where exceptions during file reading could bypass cleanup logic.