Re: [Xenomai] Issue in notifier_callback while threadobj_lock is being held (forge/mercury)

[Philippe Gerum <rpm@xenomai.org>]

On 05/01/2014 01:49 PM, Matthias Schneider wrote:

> On a first glance the commit seems to work find - I am still verifying.
> Simplifying the suspend handling, would sending a SIGNOTIFY signal straight
> to the signal handler instead of using pipe read/write operations be an
> equivalent, even simpler alternative as demonstrated in the attached patch?
>

IIRC, the reason to base the logic on fasync handling was primarily to 
allow for extending the scheme to multi-processing setups (copperplate 
provides mechanisms for sharing most of its core objects between 
processes). Typically, using an AF_UNIX named socket instead of an 
anonymous pipe would have made possible to notify threads which belong 
to different processes the same way.

Simplifying the notification path would be a good thing though, we could 
use the regular (t)kill kernel interface to send the thread-directed 
SIGNOTIFY signal, instead of pthread_kill().

-- 
Philippe.