这段代码:
Fiber.new do
Thread.current['a'] = 5
p Thread.current.object_id
p Thread.current['a']
Fiber.new do
p Thread.current.object_id
p Thread.current['a']
end.resume
p Thread.current.object_id
p Thread.current['a']
end.resume
显示以下结果:
3442840
5
3442840
nil
3442840
5
为什么current['a']
返回nil
嵌套纤维?怎么解释?