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

[Philippe Gerum <rpm@xenomai.org>]

On 05/01/2014 02:52 PM, Philippe Gerum wrote:
> 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.

Plus: passing parameters to the notification messages, which we would 
not be able to do using plain signaling. There are a few inter-process 
requests we still need to implement via the notification system. Once 
they are more specifically framed and scoped, we may get back to this 
optimization. Maybe we could use a mixed approach as well.

-- 
Philippe.