[chenBright]

What problem does this PR solve?

Issue Number: resolve

Problem Summary:

Collector uses a leaky singleton, so its destructor never stops its worker threads during normal process exit. A pending RPC dump can therefore read rpc_dump_dir after its string storage has been destroyed, causing a heap-use-after-free.

What is changed and the side effects?

Changed:

• Add an idempotent shutdown hook that stops and joins both Collector threads while retaining the singleton.
• Ensure Collector shutdown completes before RPC dump flags are destroyed, including when Collector was initialized before main().
• Serialize first-time initialization with shutdown, use an atomic stop flag, and reject submissions after shutdown.

Side effects:

• Performance effects:

• Breaking backward compatibility:

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Check List:

• Please make sure your changes are compilable.
• When providing us with a new feature, it is best to add related tests.
• Please follow Contributor Covenant Code of Conduct.

[Copilot]

🟡 Changes recommended

An active concurrency defect can allow a post-shutdown submission to escape final cleanup, and the regression tests do not cover the pre-main initialization teardown ordering.

2 open issues

• Shutdown can miss submissions that pass the stop check · New
• Exit tests do not cover pre-main collector initialization · New

What changed in this PR

This pull request adds coordinated shutdown for the process-wide bvar collector, ensuring worker threads finish before RPC dump configuration is destroyed during process exit.

Changes:

• Adds synchronized collector initialization and shutdown with an atomic stop state.
• Stops and joins collector workers, cleans up pending samples, and rejects post-shutdown submissions.
• Adds RPC dump exit-ordering safeguards.
• Adds shutdown, concurrency, and process-exit regression tests.

This pull request requires changes.

File	Description
test/​brpc_collector_shutdown_unittest.cpp	Adds process-exit and concurrency tests for collector shutdown behavior.
src/​bvar/​collector.h	Declares the internal collector shutdown hook and documents post-shutdown submission behavior.
src/​bvar/​collector.cpp	Implements serialized initialization, shutdown coordination, worker joining, pending-sample cleanup, and shutdown-aware submissions.
src/​brpc/​rpc_dump.cpp	Registers RPC dump shutdown before its flags are destroyed.

_{Review effort: Lite}

[Copilot]

🔵 Needs a closer look

Runtime sanitizer/build validation across pthread and TLS shutdown interleavings, atexit and static teardown ordering, and supported link modes was unavailable, leaving correctness and duplicate-source test-linking unconfirmed.

No open issues 🎉

2 resolved since last review

• Shutdown can miss submissions that pass the stop check
• Exit tests do not cover pre-main collector initialization

_{Review effort: Lite}

[wasphin]

LGTM