Expand description
Customization of where and how the generation lock works.
By default, all the ArcSwapAny instances share the same
generation lock. This is to save space in them (they have the same size as a single pointer),
because the default lock is quite a large data structure (it’s sharded, to prevent too much
contention between different threads). This has the disadvantage that a lock on one instance
influences another instance.
The things in this module allow customizing how the lock behaves. The default one is
Global. If you want to use independent but unsharded lock, use the
PrivateUnsharded (or the
IndependentArcSwap type alias).
Or you can implement your own lock, but you probably should study the internals of the library first.
Not Implemented Yet
These variants would probably make sense, but haven’t been written yet:
- A lock storage that is shared, but only between a certain group of pointers. It could be
either as a reference (but then each
ArcSwapwould get a bit bigger), or a macro that could generate an independent but global storage.
Structs
PrivateUnsharded, but with configurable number of shards.ArcSwap. Therefore, locks on
each instance won’t influence any other instances. On the other hand, the ArcSwap itself gets
bigger and doesn’t have multiple shards, so concurrent uses might contend each other a bit.