Re: Use standard SIGHUP and SIGTERM handlers in autoprewarm module

Hi,

On 2020-12-16 18:12:39 +0900, Fujii Masao wrote:
> -    /* Wait to be signaled by UnpinBuffer() */
> +    /*
> +     * Wait to be signaled by UnpinBuffer().
> +     *
> +     * We assume that only UnpinBuffer() and the timeout requests established
> +     * above can wake us up here. WakeupRecovery() called by walreceiver or
> +     * SIGHUP signal handler, etc cannot do that because it uses the different
> +     * latch from that ProcWaitForSignal() waits on.
> +     */
>      ProcWaitForSignal(PG_WAIT_BUFFER_PIN);
>  
>      /*

Isn't this comment bogus?  The latch could e.g. be set by
procsignal_sigusr1_handler(), which the startup process uses. Or it could
already be set, when entering ResolveRecoveryConflictWithBufferPin().

Why is it even relevant that we only get woken up by UnpinBuffer()?

Greetings,

Andres Freund