Store permanent values in the cache (for #1683)#1685
Merged
hawkw merged 5 commits intoeliza/generalize-cachefrom May 19, 2022
Merged
Store permanent values in the cache (for #1683)#1685hawkw merged 5 commits intoeliza/generalize-cachefrom
hawkw merged 5 commits intoeliza/generalize-cachefrom
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In some cases--like inbound policy discovery--we have a set of permanent values that should never be removed from the cache. This change updates the cache to only hold a handle when eviction is scheduled. No handle is held when the cache entry is permanent. This change also fixes a possible race condition. Previously, the eviction task could consume an entry's handle without locking the cache. This made it possible for a `get_or_insert_with` call to race against the eviction task, adding an entry that would be immediately evicted by the eviction task. Signed-off-by: Oliver Gould <[email protected]>
Contributor
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Oh, whoops, I missed this and made my own almost-identical version of the permanent entry part of the change: 3525055 I'm going to merge this anyway to pick up the race fix --- good catch. |
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In some cases--like inbound policy discovery--we have a set of permanent
values that should never be removed from the cache. This change updates
the cache to only hold a handle when eviction is scheduled. No handle is
held when the cache entry is permanent.
This change also fixes a possible race condition. Previously, the
eviction task could consume an entry's handle without locking the cache.
This made it possible for a
get_or_insert_withcall to race againstthe eviction task, adding an entry that would be immediately evicted by
the eviction task.
Signed-off-by: Oliver Gould [email protected]