Re: Convert close_idle_connection (SIGUSR1) to flag-only handler with main-loop processing.

> I have reviewed the patch(026-close-idle-connection-flag-only) from Emond.
> It has also passed all regression tests.
>
> The SIGUSR1 handler in the child process directly performed connection
> cleanup, including pool_free_startup_packet() and pool_close(). These
> operations are not async-signal-safe and can modify connection pool memory
> while the main loop is using it.
>
> In particular, SIGUSR1 can arrive while
> connect_using_existing_connection() is replacing startup packet pointers.
> This can cause the signal handler to free the same startup packet or
> connection pool that the main loop is currently accessing.
>
> This issue was reproduced in a local test environment, where sending
> SIGUSR1 during startup packet replacement caused the child process to
> terminate with a segmentation fault.
>
> Changes:
> Flag-only Signal Handler: Make close_idle_connection() only set a
> volatile sig_atomic_t flag and return.
>
> Main-loop Processing: Process the pending request from the child main loop
> and perform connection cleanup outside the signal handler.
>
> Direct Cleanup: Update the failover/failback restart path to call the
> cleanup function directly.
>
> Thank you Emond.

I have looked in the patch. It looks good to me.

Regards,
--
Tatsuo Ishii
SRA OSS K.K.
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