sd_global->initial_tasks = new std::set<SD_task_t>();
sd_global->runnable_tasks = new std::set<SD_task_t>();
sd_global->completed_tasks = new std::set<SD_task_t>();
sd_global->initial_tasks = new std::set<SD_task_t>();
sd_global->runnable_tasks = new std::set<SD_task_t>();
sd_global->completed_tasks = new std::set<SD_task_t>();