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A comment on Apple Engineers Its Own Downfall with the Macbook Pro Keyboard. Parent comment

Re:Apple Engineers Its Own Downfall with the Macbook Pro Key... by jmts on Thursday June 28, 2018 @01:10AM (#17414227)
Perhaps cheaper in space, but you will have to do an initial pass over the entire structure to zero your visited bits first, so it may not be cheaper in time.
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Re:Apple Engineers Its Own Downfall with the Macbook Pro Key... by ufo on Thursday June 28, 2018 @01:32AM (#17414317)
The GC already needs to sweep through the whole allocated memory to find the unreacheble objects to be freed. Flipping a bit while doing this isnt a big deal.
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Re:Apple Engineers Its Own Downfall with the Macbook Pro Key... by stcredzero on Thursday June 28, 2018 @12:41PM (#17418431)
Just ensure the bits are always zero on allocation, use DFS, and ensure you re-zero the bits on the way out.
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Re:Apple Engineers Its Own Downfall with the Macbook Pro Key... by WalterBright on Thursday June 28, 2018 @11:25PM (#17422165)
Since the first pass quit when it finds the first marked node, the zeroing can traverse the structure, erasing marked bits, and stopping at the first 0. The entire structure doesn't have to be visited.
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Re:Apple Engineers Its Own Downfall with the Macbook Pro Key... by stcredzero on Friday June 29, 2018 @08:25PM (#17428840)
The entire structure doesn't have to be visited.

We are both saying this.

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Re:Apple Engineers Its Own Downfall with the Macbook Pro Key... by WalterBright on Thursday June 28, 2018 @01:25AM (#17414284)
You have to walk the hash table again to free it.
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