On 01/04/2016 07:40 AM, Eli Zaretskii wrote:
>> From: Daniel Colascione <dancol@dancol.org>
>> Date: Sun, 3 Jan 2016 15:51:13 -0800
>>
>> How would moving to C help? Keep in mind that we're talking about fork
>> *and exec*, so the parent and child don't share memory. They can,
>> however, communicate over a pipe.
> 
> Communicating over a pipe means encoding/decoding stuff, which
> allocates memory, temporary buffers, and can potentially run Lisp.
> It's IMO unwise to do that in a crashed session.

Did you read my proposal? I suggested reading a *single byte*. POSIX
guarantees we can do that, even from async-signal-unsafe context. The
byte tells us whether to save, crash, die, or attempt to recover.

man 7 signal

But never mind. This whole ask-the-user-what-to-do thing is too
confusing. Just imagine I'd said we'd always write the save file.