<p>This crate provides two types, <ahref="https://crates.io/crates/loom"><code>Slab</code></a> and <ahref="struct.Pool.html"title="struct sharded_slab::Pool"><code>Pool</code></a>, which provide
slightly different APIs for using a sharded slab.</p>
<p><ahref="https://crates.io/crates/loom"><code>Slab</code></a> implements a slab for <em>storing</em> small types, sharing them between
threads, and accessing them by index. New entries are allocated by
<ahref="struct.Slab.html#method.insert"title="method sharded_slab::Slab::insert">inserting</a> data, moving it in by value. Similarly, entries may be
deallocated by <ahref="struct.Slab.html#method.take"title="method sharded_slab::Slab::take">taking</a> from the slab, moving the value out. This API is
similar to a <code>Vec<Option<T>></code>, but allowing lock-free concurrent insertion
and removal.</p>
<p>In contrast, the <ahref="struct.Pool.html"title="struct sharded_slab::Pool"><code>Pool</code></a> type provides an <ahref="https://en.wikipedia.org/wiki/Object_pool_pattern">object pool</a> style API for
<em>reusing storage</em>. Rather than constructing values and moving them into the
pool, as with <ahref="https://crates.io/crates/loom"><code>Slab</code></a>, <ahref="struct.Pool.html#method.create"title="method sharded_slab::Pool::create">allocating an entry</a> from the pool takes a
closure that’s provided with a mutable reference to initialize the entry in
place. When entries are deallocated, they are <ahref="trait.Clear.html"title="trait sharded_slab::Clear">cleared</a> in place. Types
which own a heap allocation can be cleared by dropping any <em>data</em> they
store, but retaining any previously-allocated capacity. This means that a
<ahref="struct.Pool.html"title="struct sharded_slab::Pool"><code>Pool</code></a> may be used to reuse a set of existing heap allocations, reducing
<p>These graphs were produced by <ahref="https://github.com/hawkw/sharded-slab/blob/master/benches/bench.rs">benchmarks</a> of the sharded slab implementation,
using the <ahref="https://crates.io/crates/criterion"><code>criterion</code></a> crate.</p>
<p>The first shows the results of a benchmark where an increasing number of
items are inserted and then removed into a slab concurrently by five
threads. It compares the performance of the sharded slab implementation
with a <code>RwLock<slab::Slab></code>:</p>
<imgwidth="1124"alt="Screen Shot 2019-10-01 at 5 09 49 PM"src="https://user-images.githubusercontent.com/2796466/66078398-cd6c9f80-e516-11e9-9923-0ed6292e8498.png">
<p>The second graph shows the results of a benchmark where an increasing
number of items are inserted and then removed by a <em>single</em> thread. It
compares the performance of the sharded slab implementation with an
<code>RwLock<slab::Slab></code> and a <code>mut slab::Slab</code>.</p>
<imgwidth="925"alt="Screen Shot 2019-10-01 at 5 13 45 PM"src="https://user-images.githubusercontent.com/2796466/66078469-f0974f00-e516-11e9-95b5-f65f0aa7e494.png">
<p>These benchmarks demonstrate that, while the sharded approach introduces
a small constant-factor overhead, it offers significantly better
</div></details><h2id="modules"class="section-header">Modules<ahref="#modules"class="anchor">§</a></h2><ulclass="item-table"><li><divclass="item-name"><aclass="mod"href="implementation/index.html"title="mod sharded_slab::implementation">implementation</a></div><divclass="desc docblock-short">Notes on <code>sharded-slab</code>’s implementation and design.</div></li><li><divclass="item-name"><aclass="mod"href="pool/index.html"title="mod sharded_slab::pool">pool</a></div><divclass="desc docblock-short">A lock-free concurrent object pool.</div></li></ul><h2id="structs"class="section-header">Structs<ahref="#structs"class="anchor">§</a></h2><ulclass="item-table"><li><divclass="item-name"><aclass="struct"href="struct.DefaultConfig.html"title="struct sharded_slab::DefaultConfig">DefaultConfig</a></div><divclass="desc docblock-short">Default slab configuration values.</div></li><li><divclass="item-name"><aclass="struct"href="struct.Entry.html"title="struct sharded_slab::Entry">Entry</a></div><divclass="desc docblock-short">A handle that allows access to an occupied entry in a <ahref="struct.Slab.html"title="struct sharded_slab::Slab"><code>Slab</code></a>.</div></li><li><divclass="item-name"><aclass="struct"href="struct.OwnedEntry.html"title="struct sharded_slab::OwnedEntry">OwnedEntry</a></div><divclass="desc docblock-short">An owned reference to an occupied entry in a <ahref="struct.Slab.html"title="struct sharded_slab::Slab"><code>Slab</code></a>.</div></li><li><divclass="item-name"><aclass="struct"href="struct.Pool.html"title="struct sharded_slab::Pool">Pool</a></div><divclass="desc docblock-short">A lock-free concurrent object pool.</div></li><li><divclass="item-name"><aclass="struct"href="struct.Slab.html"title="struct sharded_slab::Slab">Slab</a></div><divclass="desc docblock-short">A sharded slab.</div></li><li><divclass="item-name"><aclass="struct"href="struct.UniqueIter.html"title="struct sharded_slab::UniqueIter">UniqueIter</a></div><divclass="desc docblock-short">An exclusive fused iterator over the items in a <ahref="struct.Slab.html"title="struct sharded_slab::Slab"><code>Slab</code></a>.</div></li><li><divclass="item-name"><aclass="struct"href="struct.VacantEntry.html"title="struct sharded_slab::VacantEntry">VacantEntry</a></div><divclass="desc docblock-short">A handle to a vacant entry in a <ahref="struct.Slab.html"title="struct sharded_slab::Slab"><code>Slab</code></a>.</div></li></ul><h2id="traits"class="section-header">Traits<ahref="#traits"class="anchor">§</a></h2><ulclass="item-table"><li><divclass="item-name"><aclass="trait"href="trait.Clear.html"title="trait sharded_slab::Clear">Clear</a></div><divclass="desc docblock-short">Trait implemented by types which can be cleared in place, retaining any
allocated memory.</div></li><li><divclass="item-name"><aclass="trait"href="trait.Config.html"title="trait sharded_slab::Config">Config</a></div><divclass="desc docblock-short">Configuration parameters which can be overridden to tune the behavior of a slab.</div></li></ul></section></div></main></body></html>
