Re: per-thread init for overlays?

[Pierangelo Masarati <ando@sys-net.it>]

Aaron Richton wrote:

> I'm linking an external library with my overlay that needs per-process
> initialization, which I handle in my overlay_init function. I clean that
> initialization up in the on_bi.bi_destroy function. (Feel free to yell at
> me if that's the wrong place, but it seems to work.)
>
> My question is for thread-specific initialization. The external library
> claims thread safety, but in addition to the process init() call, there is
> a per-thread thread_init()/thread_end() call. They recommend,
> unsurprisingly, placing this near a pthread_create()/pthread_destroy() or
> moral equivalent. Is there any appropriate place to do this in the
> overlay?
>  
None that I'm aware of.  But I suggest you look at 
ldap_pvt_thread_pool_{get,set}key().
You could write a function like

void *private_cookie;

/* cleanup cookie & thread */
static void
private_cookie_free( void *key, void *data );

void
private_init_thread( Operation *op )
{
       void *cookie;

       ldap_pvt_thread_pool_getkey( op->o_threadctx, &private_cookie, 
&cookie, NULL );
       if ( cookie == NULL ) {
               /* init cookie & overlay */
               ldap_pvt_thread_pool_setkey( op->o_threadctx, 
&private_cookie,
                       cookie, private_cookie_free );
       }
}

Each function in your overlay could call private_thread_init() to make 
sure per-thread initialization occurred.

p.


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