Add timeout and symbol length limits to demangling #540
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| result = subprocess.run( | ||
| command_parts, capture_output=True, text=True, check=True, timeout=DEFAULT_DEMANGLE_TIMEOUT | ||
| ) | ||
| except subprocess.TimeoutExpired: | ||
| elapsed = time.time() - start_time | ||
| logger.warning(f"Chunk {chunk_idx} timed out after {elapsed:.1f}s") | ||
| return {} |
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Bug: The subprocess.run call does not explicitly terminate the child process when a TimeoutExpired exception is caught, which could lead to orphan processes.
Severity: HIGH
Suggested Fix
In the except subprocess.TimeoutExpired block, add logic to explicitly terminate the child process. You can access the process via the .child attribute of the TimeoutExpired exception object and call its .kill() method to ensure it is properly cleaned up.
Prompt for AI Agent
Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.
Location: src/launchpad/utils/apple/cwl_demangle.py#L208-L214
Potential issue: When the `subprocess.run` call in `cwl_demangle.py` times out, the
`TimeoutExpired` exception is caught, but the child `cwl-demangle` process may not be
terminated. This could lead to an accumulation of zombie or orphan processes, consuming
system resources. While the behavior of `subprocess.run` on timeout can vary between
Python versions, explicitly terminating the process is the safest approach to ensure
proper resource cleanup, a pattern seen elsewhere in the codebase.
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We were seeing a build with some extremely long symbols that can cause the demangling process to hang. This is an idea for curbing the impact: