Emit telemetry when create-instance steps exceed 10s

[shuaiyuanxx]

Summary of the Pull Request

Adds SlowOperationWatcher, an RAII guard that emits a SlowOperation telemetry event when a scoped step exceeds 10 s, so slow CreateInstance starts can be attributed to a specific phase (HCS op, kernel boot, init-daemon wait, plugin hook) instead of the opaque timeout bucket.

Fast path emits nothing. Slow path emits one SlowOperation event carrying name, thresholdMs, and the call site (file, function, line) captured via std::source_location.

PR Checklist

• Closes: Link to issue #xxx
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• Tests: Added/updated if needed and all pass
• Localization: All end user facing strings can be localized
• Dev docs: Added/updated if needed
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description

src/windows/common/SlowOperationWatcher.{h,cpp} is a single-shot threadpool timer guard. wil::unique_threadpool_timer's destroyer cancels and drains on scope exit, so the callback cannot touch *this after destruction. Reset() disarms early for cases where the scope must outlive the watched call (e.g. to keep a ReceiveMessage buffer reference alive). Name is restricted to const char (&)[N] to enforce static storage.

12 call sites wrapped:

• WslCoreVm.cpp: HcsCreateSystem, HcsStartSystem, WaitForMiniInitConnect, ReadGuestCapabilities, CreateNatNetwork, AttachDistroVhd, WaitForInitDaemonConnect
• WslCoreInstance.cpp: WaitForCreateInstanceResult, WaitForDrvFsInit, WaitForInitConfigResponse
• PluginManager.cpp: PluginOnVmStarted, PluginOnDistributionStarted

Call-site business logic is unchanged. No user-facing path.

Validation Steps Performed

Validated end-to-end against a Debug wslservice.exe with ETW capture:

• Fast path: wsl --shutdown + wsl -d Ubuntu -e echo hello — all guarded sites exercised, zero SlowOperation events.
• Slow path: injected Sleep(11000) inside WaitForMiniInitConnect — one SlowOperation{name="WaitForMiniInitConnect", thresholdMs=10000, file, function, line} event emitted.

[Copilot]

Pull request overview

This PR adds slow-operation instrumentation across VM/instance startup paths and updates the build pipeline to retain and publish binaries alongside PDBs during symbol publication.

Changes:

• Introduce WslSlowOperation (RAII + threadpool-timer) to emit telemetry/logs when scoped operations exceed a threshold.
• Wrap several VM/instance startup and plugin hook calls with WslSlowOperation scopes to measure slow phases.
• Update pipeline symbol publishing to also upload .exe/.dll binaries and avoid deleting test DLLs during staging.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/windows/service/exe/WslCoreVm.cpp	Adds WslSlowOperation scopes around key VM startup and instance creation operations.
src/windows/service/exe/WslCoreInstance.cpp	Narrows slow-operation timing specifically around blocking receives from init.
src/windows/service/exe/PluginManager.cpp	Adds slow-operation timing around plugin hook invocations.
src/windows/common/precomp.h	Exposes WslSlowOperation via the common precompiled header.
src/windows/common/WslSlowOperation.h	New RAII helper declaration for slow-operation timing and telemetry.
src/windows/common/WslSlowOperation.cpp	Implements timer-based slow threshold detection and start/end telemetry emission.
src/windows/common/CMakeLists.txt	Adds the new WslSlowOperation files to the common build.
.pipelines/build-job.yml	Keeps DLLs in bin/ and expands symbol publishing inputs to include .exe/.dll.

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 4 comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated no new comments.

[shuaiyuanxx]

Hi @OneBlue, Thanks for the thorough review! All of your suggestions have been addressed — PTAL when you have a moment.