ObjectSpace.count_objects中每个哈希值的含义是什么?

时间:2013-07-26 22:40:21

标签: ruby-on-rails ruby objectspace

在ruby 1.9.3中,我使用ObjectSpace来检查内存问题。 ObjectSpace.count_objects返回一个哈希,如下所示:

{:TOTAL=>1004232, :FREE=>258543, :T_OBJECT=>12519, :T_CLASS=>10318, :T_MODULE=>1330,    
:T_FLOAT=>2024, :T_STRING=>555422, :T_REGEXP=>3543, :T_ARRAY=>68372, :T_HASH=>5399,
:T_STRUCT=>542, :T_BIGNUM=>8105, :T_FILE=>10, :T_DATA=>44277, :T_MATCH=>6, :T_COMPLEX=>1,   
:T_RATIONAL=>82, :T_NODE=>31973, :T_ICLASS=>1766}

每个哈希值是什么意思?特别是,为什么:TOTAL长时间保持不变?这是否意味着没有创建新对象?

我看到similar posting,但还没有好的答案。

1 个答案:

答案 0 :(得分:1)

>> ObjectSpace.count_objects
=> {:TOTAL=>30205, :FREE=>131, :T_OBJECT=>1550, :T_CLASS=>921, :T_MODULE=>31, :T_FLOAT=>7, :T_STRING=>18368, :T_REGEXP=>185, :T_ARRAY=>4
196, :T_HASH=>254, :T_STRUCT=>1, :T_BIGNUM=>3, :T_FILE=>9, :T_DATA=>1311, :T_MATCH=>84, :T_COMPLEX=>1, :T_NODE=>3121, :T_ICLASS=>32}
>> class MyClass ; end
=> nil
>> ObjectSpace.count_objects
=> {:TOTAL=>30205, :FREE=>203, :T_OBJECT=>1562, :T_CLASS=>923, :T_MODULE=>31, :T_FLOAT=>7, :T_STRING=>18333, :T_REGEXP=>185, :T_ARRAY=>4
274, :T_HASH=>268, :T_STRUCT=>1, :T_BIGNUM=>3, :T_FILE=>9, :T_DATA=>1320, :T_MATCH=>97, :T_COMPLEX=>1, :T_NODE=>2956, :T_ICLASS=>32}
>> MyClass = nil
(irb):4: warning: already initialized constant MyClass
(irb):2: warning: previous definition of MyClass was here
=> nil
>> ObjectSpace.count_objects
=> {:TOTAL=>30205, :FREE=>87, :T_OBJECT=>1572, :T_CLASS=>923, :T_MODULE=>31, :T_FLOAT=>7, :T_STRING=>18425, :T_REGEXP=>185, :T_ARRAY=>43
39, :T_HASH=>279, :T_STRUCT=>1, :T_BIGNUM=>3, :T_FILE=>9, :T_DATA=>1328, :T_MATCH=>107, :T_COMPLEX=>1, :T_NODE=>2876, :T_ICLASS=>32}
>> MyClass
=> nil
>> GC.start
=> nil
>> ObjectSpace.count_objects
=> {:TOTAL=>30205, :FREE=>7356, :T_OBJECT=>1549, :T_CLASS=>921, :T_MODULE=>31, :T_FLOAT=>7, :T_STRING=>14100, :T_REGEXP=>184, :T_ARRAY=>
3821, :T_HASH=>244, :T_STRUCT=>1, :T_BIGNUM=>3, :T_FILE=>5, :T_DATA=>1285, :T_MATCH=>8, :T_COMPLEX=>1, :T_NODE=>657, :T_ICLASS=>32}
>> 

查看T_CLASS对象,我们可以看到这些是计数。当我删除该类并启动垃圾收集器时,它会再次减少计数。

TOTAL值保持不变并不意味着没有创建对象,显然当您创建一个新对象(如MyClass)时,计数没有改变。这可能意味着它只是偶尔重新评估总数,而不是实时。

但是,通过一些数学运算,当我对值求和,并删除TOTAL计数时,我得到TOTAL。因此,当count_objects报告对象计数时,看起来它是对象数量的计数。