[DecviL]

Background

PinK 0.0.2.0 fails to start a project on an exFAT drive because backend ownership acquisition publishes a persistent port registry using a hard link, which exFAT does not support. The reported failure is EISDIR in ProjectBackendLease.acquire.

Bug report: https://forum.cocos.org/t/topic/177872/5?u=weijinda

Persisting a control port across restarts can also block normal startup when that port has subsequently been allocated to another project or application.

Implementation

• Remove the persistent rendezvous/port.json registry and hard-link publication. Each backend startup binds 127.0.0.1 on port 0, allowing the OS to allocate a currently available control port.
• Atomically publish the instance address and credentials in owner.json. Discovery validates the live project and instance identity; missing, corrupt, unrelated, or unresponsive stale metadata does not pin a new startup to an old port.
• Obtain a newly spawned backend's readiness descriptor directly over parent/child IPC, so overlapping owner.json writes cannot make a caller mistake another process for its own child.
• Query and stop a specific instance using its descriptor and authenticated control endpoint. Retain stale discovery metadata on shutdown to avoid deleting another instance's newer publication.
• Update lifecycle tests and documentation. No dependencies are added.

Behavior change: cross-process project exclusivity is no longer enforced. Independent startup commands may create separate backends for the same project; callers must coordinate concurrent project writes. ensureProjectBackend reuses a discoverable backend and shares concurrent startup requests within the calling process. Old registry paths are neither read nor migrated.

Testing

• Passed: TypeScript build:

  node node_modules/typescript/bin/tsc -b

• Passed on Windows / NTFS: 16 tests covering dynamic ports, concurrent subprocess startup, stale or corrupt metadata, former ports occupied by unrelated or unresponsive services, authenticated shutdown, and launcher cleanup:

  node node_modules/jest/bin/jest.js --config jest.config.ts --runInBand --runTestsByPath tests/project-backend-client.test.ts tests/project-backend-ownership.test.ts tests/project-backend-launcher.test.ts --silent

• Passed on an actual exFAT volume (E:): all 10 backend discovery/ownership tests with COCOS_BACKEND_TEST_TMPDIR=E:\. The Windows junction assertion is omitted when a custom test directory is configured.
• Passed: real managed MCP/Scene backend integration test with COCOS_TEST_PROJECT_BACKEND=1, covering startup, reuse, explicit shutdown, restart, and stale-descriptor handling.
• Passed: git diff --check.

[wuzhiming]

未发现本次改动引入且有充分证据可确认的问题，仅完成静态审查，不代表测试通过。审查范围：三个文件的所提供 patch；对照 base 与 head 的 ownership.ts，并读取 head 的启动客户端、Launcher、所有权测试及相关测试辅助代码，核对并发发布、注册信息校验、监听器关闭和临时目录清理。无 patch 的相关文件仅用于验证调用关系，未作完整审查。未运行测试或构建，未实测 Windows、NTFS/exFAT 的目录重命名行为及真实后端集成；文档仅审查所提供差异。固定审查提交：18e3dce7，对照基线：e683ccc8。

PR 审查：#1011
审查提交：18e3dce7090adaf66c554fd1e6db8aa462f86b4e
Base：e683ccc80479aeda84365121f7bb5597f456c38f

验证范围：3 个变更文件，另读取 8 个提交内文件；静态审查，未运行构建或测试，未修改代码。