Add: unit tests for PTO2 scheduler core data structures and hot-paths

[chenshengxin2026]

Summary

The core data structures (task allocator, dep-list pool, fanin pool, SPSC queue, tensor map) and scheduling hot-paths (wire_task, on_mixed_task_complete, on_task_release, advance_ring_pointers) in the PTO2 A2A3 scheduler previously had no unit test coverage. Bugs in these paths — off-by-one in wrap-around, stale fanin references, lost dependency edges — only surface under specific task-graph topologies and are extremely hard to diagnose at the system-test level.

This PR adds per-component unit tests:

• test_task_allocator — heap bump, wrap-around guard, flow-control window
• test_task_state — slot lifecycle driven through src API, profiling CAS semantics
• test_dep_list_pool / test_fanin_pool — ring allocation, overflow detection, tail advance
• test_spsc_queue — cached-index SPSC correctness, wrap, capacity semantics
• test_tensormap — hash distribution, overlap detection, lookup saturation
• test_wiring — end-to-end wire → complete → release → advance cycle

These tests also serve as executable documentation of design contracts (e.g. heap_available reports max-not-sum, LIFO dispatch for cache locality, relaxed size() as a hint only).

Test plan

• cmake -B tests/ut/cpp/build -S tests/ut/cpp && cmake --build tests/ut/cpp/build -j$(nproc)
• ctest --test-dir tests/ut/cpp/build -L no_hardware --output-on-failure
• All new and modified test binaries pass

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[ChaoZheng109]

建议删除这一行新增的 include 目录,改为让 UT 的 #include 与生产代码保持一致。

生产代码里所有引用 pto_scheduler.h 的地方都用带子目录前缀的形式:

• src/a2a3/runtime/tensormap_and_ringbuffer/runtime/pto_orchestrator.h:34: #include "scheduler/pto_scheduler.h"
• src/a2a3/runtime/tensormap_and_ringbuffer/runtime/pto_ring_buffer.cpp:25: #include "scheduler/pto_scheduler.h"
• src/a2a3/runtime/tensormap_and_ringbuffer/runtime/pto_runtime2.h:43: #include "scheduler/pto_scheduler.h"

约定是: include path 只暴露 runtime/,然后用 scheduler/pto_scheduler.h 作相对路径。这样 scheduler/ / shared/ 这些子目录的归属在 #include 行里就可见,不会被 flatten。

本 PR 里 5 个 UT 文件用的是短路径写法(#include "pto_scheduler.h"),为了让它们能 resolve,CMake 被迫追加了 runtime/scheduler 这个额外的 include 目录。建议反过来做:

改 5 个 test 文件的 include:

• tests/ut/cpp/a2a3/test_wiring.cpp:32
• tests/ut/cpp/a2a3/test_ready_queue.cpp:47
• tests/ut/cpp/a2a3/test_spsc_queue.cpp:30
• tests/ut/cpp/a2a3/test_task_state.cpp:31
• tests/ut/cpp/a2a3/test_scheduler_state.cpp:22

把 #include "pto_scheduler.h" 改成 #include "scheduler/pto_scheduler.h",然后回滚本行。

为什么不是风格偏好而已: 将来如果 scheduler/ 再被拆分(例如 scheduler/hot/ + scheduler/cold/),生产代码的 #include "scheduler/..." 必须跟着改;但 UT 的短路径 include 只要 CMake 同步 include path 就还能编译,于是 UT 的 include 解析可能偏离生产代码 —— UT 以为自己在测同一个头文件,实际链路已经不同。保持对称就不会出这种静默漂移。