Method return_item

benchmarks/tbb/pipeline.cpp:212–223

return an item, invalidate the queued item, but only advance if advance advance == true for parallel filters. If the filter is serial, leave the item in the buffer to keep another stage from being spawned.

    //  advance == true for parallel filters.  If the filter is serial, leave the
    // item in the buffer to keep another stage from being spawned.
    bool return_item(task_info& info, bool advance) {
        spin_mutex::scoped_lock lock( array_mutex );
        task_info& item = array[low_token&(array_size-1)];
        ITT_NOTIFY( sync_acquired, this );
        if( item.is_valid ) {
            info = item;
            item.is_valid = false;
            if (advance) low_token++;
            return true;
        }
        return false;
    }

    //! true if the current low_token is valid.
    bool has_item() { spin_mutex::scoped_lock lock(array_mutex); return array[low_token&(array_size -1)].is_valid; }