Re: glibc / proc server interaction

[Brent W. Baccala]

On Mon, Feb 5, 2018 at 1:51 AM, Samuel Thibault <samuel.thibault@gnu.org> wrote:

Hello,

Brent W. Baccala, on lun. 05 févr. 2018 00:35:17 -0500, wrote:
> How do we know that the proc server knows about the task yet?  It will get a
> notification from the kernel that a new task has been created, but how do we
> know that the notification has been processed yet?

Isn't the notification synchronous ?

I don't see how.  The kernel just sends a mach_notify_new_task message, and there is no reply.

I see that the proc server increases its own scheduling priority (line 217 in proc/main.c), which is probably why the notification gets processed before the fork() resumes, but I don't see anything else to achieve synchronization.

If that's the explanation, then we should think about how to synchronize that exchange without relying on scheduling priority.

    agape

    brent