[SCM] Samba Shared Repository - branch master updated

[Volker Lendecke]

On Thu, Dec 18, 2014 at 08:21:04AM -0500, Poornima Gurusiddaiah wrote:
> > That will remove the immediate concerns about pthread
> > calls being used in the module, but still the
> > calls to glfs_pread_async() are there, so the more sublte
> > concern remains how the gluster gfapi library uses threads
> > (and whether it can be avoided). I am currently looking
> > into the code, trying to understand it, but I'm sure we
> > will also get an update and information from Poornima,
> > the patch author.
> > 
> Glusterfs is a multithreaded application. glfs_pread_async() doesn't really
> create any more threads as compared to glfs_pread() api(which is the sync api).
> By default when a connection to libgfapi is established (glfs_init()) there will
> be 4 threads created, and will increase as the load increases. Out of four, we have
> one queuing thread(which will grow) and one poller thread which receives the
> acknowledgments from server.

Just to make sure: It's okay to fork() at any point while there are
glusterfs threads doing their work, wherever they might be blocked? That
would mean to properly mutex_lock all independent mutexes in the
pthread_atfork prepare handler and unlocking those in the parent and
child handlers, closing and possibly re-opening resources in the child?

Thanks,

Volker

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