CmdRun: join pipe reader threads before close returns

[satishnaidu77]

Summary

CmdRun#close waited for the child process with Process.wait2, then returned immediately while stdout/stderr were still being read in background threads. Callers that inspect stddata right after close could see incomplete output.

This showed up in functest host commands (e.g. ping -c 10): the command succeeded and printed PASS:, but validation ran before the last lines were buffered, causing false failures like expected to contain 'PASS:'.

Fix

• Track stdout/stderr pipe reader threads in @pipe_threads
• Join those threads in close after wait2 and before returning

Test

Add a spec that runs slow stdout and asserts stddata['stdout'] is complete when close returns (no polling). Existing cmd_run_spec tests check exit status and logging, but do not cover this race.

Test plan

• bundle exec rspec spec/lib/auxiliary/cmd_run_spec.rb — 8 examples, 0 failures

[Copilot]

🟢 Approval recommended

The change directly addresses the described race by joining the stdout/stderr reader threads before returning from close, and includes a targeted regression spec to prevent reintroduction.

Pull request overview

This PR fixes a race in AutoHCK::CmdRun#close where the method could return after the child process exited but before the stdout/stderr pipe-reader threads finished buffering output, leading callers to observe incomplete stddata.

Changes:

• Track stdout/stderr pipe reader threads in @pipe_threads.
• Join pipe reader threads in #close after Process.wait2 and before returning.
• Add an RSpec example that verifies stdout is complete immediately after close returns (no polling).

File summaries

File	Description
lib/auxiliary/cmd_run.rb	Tracks pipe reader threads and joins them during close so stddata is fully buffered before returning.
spec/lib/auxiliary/cmd_run_spec.rb	Adds a regression test for the stdout-buffering race by producing slow, line-by-line output and asserting completeness after close.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 0
• Review effort level: Lite

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[kostyanf14]

ok to test

[kostyanf14]

rerun tests