spinlock variable protection

Malte Vesper malte.vesper at postgrad.manchester.ac.uk
Fri Jan 30 10:23:10 EST 2015

Spinlocks imply memory barriers as far as I am aware...

Read here: 

On 30/01/15 14:20, Matwey V. Kornilov wrote:
> 2015-01-30 16:52 GMT+03:00 buyitian <buyitian at gmail.com>:
>> Please check the assembly code to double confirm the GCC behavior.
>> Why will GCC change the order as what you mentioned? Only assembly code can tell you.
> It does not change at the moment. I think it can change it.
> Because from line
>    ret = hdl->count;
> until line
>    return ret;
> there is no access to either ret or hdl->count. So it is reasonable to
> optimizer to think that their values are the same and eliminate
> unneeded variable.

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