Message361138
| Author |
vstinner |
| Recipients |
eric.snow, jkloth, nanjekyejoannah, ncoghlan, vstinner |
| Date |
2020年02月01日.00:30:57 |
| SpamBayes Score |
-1.0 |
| Marked as misclassified |
Yes |
| Message-id |
<1580517057.49.0.13192433757.issue39511@roundup.psfhosted.org> |
| In-reply-to |
| Content |
> Would it not suffice to just make the singletons "immortal"?
The problem is to make Py_INCREF/Py_DECREF efficient. Last time someone tried to use an atomic variable for ob_refcnt, it was 20% slower if I recall correctly. If many threads start to update such atomic variable, the CPU cacheline of common singletons like None, True and False can quickly become a performance bottleneck.
On the other side, if each interpreter has its own objects, there is no need to protect ob_refcnt, the interpreter lock protects it. |
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