rem: rmv_from_timer_list( &(ses->tl) );
add: rmv_from_timer_list( &(ses->tl), ses_mgr.ses_timer );
context: void destroy_session( struct session *ses){	if (ses) {		if ( ses->sID.s)			shm_free( ses->sID.s );		if ( ses->tl.timer_list )			rmv_from_timer_list( &(ses->tl) );		shm_free(ses);	}}