Method clear

benchmarks/tbb/observer_proxy.cpp:90–122

}

void observer_list::clear () {
    __TBB_ASSERT( this != &the_global_observer_list, "Method clear() cannot be used on the list of global observers" );
    // Though the method will work fine for the empty list, we require the caller
    // to check for the list emptiness before invoking it to avoid extra overhead.
    __TBB_ASSERT( !empty(), NULL );
    {
        scoped_lock lock(mutex(), /*is_writer=*/true);
        observer_proxy *next = my_head;
        while ( observer_proxy *p = next ) {
            __TBB_ASSERT( p->my_version >= 6, NULL );
            next = p->my_next;
            // Both proxy p and observer p->my_observer (if non-null) are guaranteed
            // to be alive while the list is locked.
            task_scheduler_observer_v3 *obs = p->my_observer;
            // Make sure that possible concurrent observer destruction does not
            // conflict with the proxy list cleanup.
            if ( !obs || !(p = (observer_proxy*)__TBB_FetchAndStoreW(&obs->my_proxy, 0)) )
                continue;
            // accessing 'obs' after detaching of obs->my_proxy leads to the race with observer destruction
            __TBB_ASSERT( !next || p == next->my_prev, NULL );
            __TBB_ASSERT( is_alive(p->my_ref_count), "Observer's proxy died prematurely" );
            __TBB_ASSERT( p->my_ref_count == 1, "Reference for observer is missing" );
#if TBB_USE_ASSERT
            p->my_observer = NULL;
            p->my_ref_count = 0;
#endif /* TBB_USE_ASSERT */
            remove(p);
            delete p;
        }
    }
    while( my_head )
        __TBB_Yield();
}

void observer_list::insert ( observer_proxy* p ) {
    scoped_lock lock(mutex(), /*is_writer=*/true);