sys:statistics/3
允许或禁止收集统计数据
用法：
statistics(Name, Flag, Timeout) -> ok | {ok, Statistics}
允许或禁止收集统计数据，参数 Timeout 表示该操作的超时时间。
参数 Flag 的取值有：
- true：允许收集统计
- get：获取收集的统计信息
- false：禁止收集统计
RegisteredList = erlang:registered(), RegisteredListLen = length(RegisteredList), ranDOM:seed(erlang:now()), Rand = random:uniform(RegisteredListLen), RegisterName = lists:nth(Rand, RegisteredList), sys:statistics(RegisterName, true, 5000).
RegisteredList = erlang:registered(), RegisteredListLen = length(RegisteredList), random:seed(erlang:now()), Rand = random:uniform(RegisteredListLen), RegisterName = lists:nth(Rand, RegisteredList), sys:statistics(RegisterName, get, 5000).
RegisteredList = erlang:registered(), RegisteredListLen = length(RegisteredList), random:seed(erlang:now()), Rand = random:uniform(RegisteredListLen), RegisterName = lists:nth(Rand, RegisteredList), sys:statistics(RegisterName, false, 5000).