claude-code - 💡(How to fix) Fix Orphaned Claude Code process enters 100% CPU busy loop when parent terminal is closed [2 comments, 2 participants]

• Process consumed 101% CPU for 17+ hours after the parent terminal was closed
• SIGTERM was ignored — only SIGKILL terminated it
• sample output showed the main thread in a tight loop with no I/O waits — pure busy spinning
• A zombie child process (<defunct>) was present, suggesting lifecycle management broke down
• No network connections were open — the process was not communicating with the API

TL;DR

The claude process likely needs to be modified to handle the case when its parent terminal is closed, to prevent it from entering a CPU-bound busy loop.

Guidance

• Investigate how the claude process handles SIGHUP signals, which are typically sent when a terminal is closed, to determine why it is not terminating as expected.
• Review the code for any potential issues with signal handling, such as ignoring SIGTERM or not properly handling SIGHUP.
• Consider adding a mechanism for the claude process to detect when its parent terminal has been closed, such as by checking for the existence of the terminal or its file descriptor.
• Look into the zombie child process (<defunct>) to understand why it is not being properly cleaned up, which may be related to the lifecycle management issue.

Example

No code snippet can be provided without more information about the claude process's codebase.

Notes

The issue seems to be specific to the claude process and its handling of terminal closure, so any solution will likely require modifications to the process itself.

Recommendation

Apply a workaround to handle the case when the parent terminal is closed, such as by sending a SIGTERM signal to the claude process when the terminal is closed, until a proper fix can be implemented in the claude process code.