[#benchmarks]
:idprefix: benchmarks_

= Benchmarks

== boost::unordered_[multi]set

All benchmarks were created using `unordered_set<unsigned int>` (non-duplicate) and `unordered_multiset<unsigned int>` (duplicate). The source code can be https://github.com/boostorg/boost_unordered_benchmarks/tree/boost_unordered_set[found here^].

The insertion benchmarks insert `n` random values, where `n` is between 10,000 and 3 million. For the duplicated benchmarks, the same random values are repeated an average of 5 times.

The erasure benchmarks erase all `n` elements randomly until the container is empty. Erasure by key uses `erase(const key_type&)` to remove entire groups of equivalent elements in each operation.

The successful lookup benchmarks are done by looking up all `n` values, in their original insertion order.

The unsuccessful lookup benchmarks use `n` randomly generated integers but using a different seed value.

=== GCC 12 + libstdc++-v3, x64

==== Insertion

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/gcc/running insertion.xlsx.practice.png[width=250,link=_images/benchmarks-set/gcc/running insertion.xlsx.practice.png,window=_blank]
|image::benchmarks-set/gcc/running insertion.xlsx.practice non-unique.png[width=250,link=_images/benchmarks-set/gcc/running insertion.xlsx.practice non-unique.png,window=_blank]
|image::benchmarks-set/gcc/running insertion.xlsx.practice non-unique 5.png[width=250,link=_images/benchmarks-set/gcc/running insertion.xlsx.practice non-unique 5.png,window=_blank]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5
|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/gcc/running insertion.xlsx.practice norehash.png[width=250,link= _images/benchmarks-set/gcc/running insertion.xlsx.practice norehash.png,window=_blank]
|image::benchmarks-set/gcc/running insertion.xlsx.practice norehash non-unique.png[width=250,link= _images/benchmarks-set/gcc/running insertion.xlsx.practice norehash non-unique.png,window=_blank]
|image::benchmarks-set/gcc/running insertion.xlsx.practice norehash non-unique 5.png[width=250,link= _images/benchmarks-set/gcc/running insertion.xlsx.practice norehash non-unique 5.png,window=_blank]

h|non-duplicate elements, +
prior `reserve`
h|duplicate elements, +
prior `reserve`
h|duplicate elements, +
max load factor 5, +
prior `reserve`

|===

==== Erasure

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/gcc/scattered erasure.xlsx.practice.png[width=250,link= _images/benchmarks-set/gcc/scattered erasure.xlsx.practice.png,window=_blank]
|image::benchmarks-set/gcc/scattered erasure.xlsx.practice non-unique.png[width=250,link= _images/benchmarks-set/gcc/scattered erasure.xlsx.practice non-unique.png,window=_blank]
|image::benchmarks-set/gcc/scattered erasure.xlsx.practice non-unique 5.png[width=250,link= _images/benchmarks-set/gcc/scattered erasure.xlsx.practice non-unique 5.png,window=_blank]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5

|
|image::benchmarks-set/gcc/scattered erasure by key.xlsx.practice non-unique.png[width=250,link= _images/benchmarks-set/gcc/scattered erasure by key.xlsx.practice non-unique.png,window=_blank]
|image::benchmarks-set/gcc/scattered erasure by key.xlsx.practice non-unique 5.png[width=250,link= _images/benchmarks-set/gcc/scattered erasure by key.xlsx.practice non-unique 5.png,window=_blank]

|
h|by key, duplicate elements
h|by key, duplicate elements, +
max load factor 5

|===

==== Successful Lookup

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/gcc/scattered successful looukp.xlsx.practice.png[width=250,window=_blank,link= _images/benchmarks-set/gcc/scattered successful looukp.xlsx.practice.png]
|image::benchmarks-set/gcc/scattered successful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link= _images/benchmarks-set/gcc/scattered successful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/gcc/scattered successful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link= _images/benchmarks-set/gcc/scattered successful looukp.xlsx.practice non-unique 5.png]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5

|===

==== Unsuccessful lookup

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice.png[width=250,window=_blank,link= _images/benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice.png]
|image::benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link= _images/benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link= _images/benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice non-unique 5.png]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5

|===

=== Clang 15 + libc++, x64

==== Insertion

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice.png[width=250, window=_blank,link= _images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice.png]
|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice non-unique.png[width=250, window=_blank,link= _images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice non-unique.png]
|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice non-unique 5.png[width=250, window=_blank,link= _images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice non-unique 5.png]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5

|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash.png]
|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash non-unique.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash non-unique.png]
|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash non-unique 5.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash non-unique 5.png]

h|non-duplicate elements, +
prior `reserve`
h|duplicate elements, +
prior `reserve`
h|duplicate elements, +
max load factor 5, +
prior `reserve`

|===

==== Erasure

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice.png]
|image::benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice non-unique.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice non-unique.png]
|image::benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice non-unique 5.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice non-unique 5.png]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5

|
|image::benchmarks-set/clang_libcpp/scattered erasure by key.xlsx.practice non-unique.png[width=250,link= _images/benchmarks-set/clang_libcpp/scattered erasure by key.xlsx.practice non-unique.png,window=_blank]
|image::benchmarks-set/clang_libcpp/scattered erasure by key.xlsx.practice non-unique 5.png[width=250,link= _images/benchmarks-set/clang_libcpp/scattered erasure by key.xlsx.practice non-unique 5.png,window=_blank]

|
h|by key, duplicate elements
h|by key, duplicate elements, +
max load factor 5

|===

==== Successful lookup

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice.png]
|image::benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice non-unique 5.png]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5

|===

==== Unsuccessful lookup

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice.png]
|image::benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link= _images/benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice non-unique 5.png]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5

|===

=== Visual Studio 2022 + Dinkumware, x64

==== Insertion

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/vs/running insertion.xlsx.practice.png[width=250,window=_blank,link= _images/benchmarks-set/vs/running insertion.xlsx.practice.png]
|image::benchmarks-set/vs/running insertion.xlsx.practice non-unique.png[width=250,window=_blank,link= _images/benchmarks-set/vs/running insertion.xlsx.practice non-unique.png]
|image::benchmarks-set/vs/running insertion.xlsx.practice non-unique 5.png[width=250,window=_blank,link= _images/benchmarks-set/vs/running insertion.xlsx.practice non-unique 5.png]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5

|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/vs/running insertion.xlsx.practice norehash.png[width=250,window=_blank,link= _images/benchmarks-set/vs/running insertion.xlsx.practice norehash.png]
|image::benchmarks-set/vs/running insertion.xlsx.practice norehash non-unique.png[width=250,window=_blank,link= _images/benchmarks-set/vs/running insertion.xlsx.practice norehash non-unique.png]
|image::benchmarks-set/vs/running insertion.xlsx.practice norehash non-unique 5.png[width=250,window=_blank,link= _images/benchmarks-set/vs/running insertion.xlsx.practice norehash non-unique 5.png]

h|non-duplicate elements, +
prior `reserve`
h|duplicate elements, +
prior `reserve`
h|duplicate elements, +
max load factor 5, +
prior `reserve`

|===

==== Erasure

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/vs/scattered erasure.xlsx.practice.png[width=250,window=_blank,link= _images/benchmarks-set/vs/scattered erasure.xlsx.practice.png]
|image::benchmarks-set/vs/scattered erasure.xlsx.practice non-unique.png[width=250,window=_blank,link= _images/benchmarks-set/vs/scattered erasure.xlsx.practice non-unique.png]
|image::benchmarks-set/vs/scattered erasure.xlsx.practice non-unique 5.png[width=250,window=_blank,link= _images/benchmarks-set/vs/scattered erasure.xlsx.practice non-unique 5.png]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5

|
|image::benchmarks-set/vs/scattered erasure by key.xlsx.practice non-unique.png[width=250,link= _images/benchmarks-set/vs/scattered erasure by key.xlsx.practice non-unique.png,window=_blank]
|image::benchmarks-set/vs/scattered erasure by key.xlsx.practice non-unique 5.png[width=250,link= _images/benchmarks-set/vs/scattered erasure by key.xlsx.practice non-unique 5.png,window=_blank]

|
h|by key, duplicate elements
h|by key, duplicate elements, +
max load factor 5

|===

==== Successful lookup

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/vs/scattered successful looukp.xlsx.practice.png[width=250,window=_blank,link= _images/benchmarks-set/vs/scattered successful looukp.xlsx.practice.png]
|image::benchmarks-set/vs/scattered successful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link= _images/benchmarks-set/vs/scattered successful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/vs/scattered successful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link= _images/benchmarks-set/vs/scattered successful looukp.xlsx.practice non-unique 5.png]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5

|===

==== Unsuccessful lookup

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice.png[width=250,window=_blank,link= _images/benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice.png]
|image::benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link= _images/benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link= _images/benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice non-unique 5.png]

h|non-duplicate elements
h|duplicate elements
h|duplicate elements, +
max load factor 5

|===

== boost::unordered_(flat|node)_map

All benchmarks were created using:

* `https://abseil.io/docs/cpp/guides/container[absl::flat_hash_map^]<uint64_t, uint64_t>`
* `boost::unordered_map<uint64_t, uint64_t>`
* `boost::unordered_flat_map<uint64_t, uint64_t>`
* `boost::unordered_node_map<uint64_t, uint64_t>`

The source code can be https://github.com/boostorg/boost_unordered_benchmarks/tree/boost_unordered_flat_map[found here^].

The insertion benchmarks insert `n` random values, where `n` is between 10,000 and 10 million.

The erasure benchmarks erase traverse the `n` elements and erase those with odd key (50% on average).

The successful lookup benchmarks are done by looking up all `n` values, in their original insertion order.

The unsuccessful lookup benchmarks use `n` randomly generated integers but using a different seed value.


=== GCC 12, x64


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/gcc-x64/Running insertion.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/gcc-x64/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x64/Running erasure.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/gcc-x64/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x64/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/gcc-x64/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x64/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/gcc-x64/Scattered unsuccessful looukp.xlsx.plot.png]

h|running insertion
h|running erasure
h|successful lookup
h|unsuccessful lookup

|===

=== Clang 15, x64


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/clang-x64/Running insertion.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-x64/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x64/Running erasure.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-x64/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x64/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-x64/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x64/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-x64/Scattered unsuccessful looukp.xlsx.plot.png]

h|running insertion
h|running erasure
h|successful lookup
h|unsuccessful lookup

|===

=== Visual Studio 2022, x64


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/vs-x64/Running insertion.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/vs-x64/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x64/Running erasure.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/vs-x64/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x64/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/vs-x64/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x64/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/vs-x64/Scattered unsuccessful looukp.xlsx.plot.png]

h|running insertion
h|running erasure
h|successful lookup
h|unsuccessful lookup

|===

=== Clang 12, ARM64


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/clang-arm64/Running insertion.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-arm64/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/clang-arm64/Running erasure.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-arm64/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/clang-arm64/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-arm64/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/clang-arm64/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-arm64/Scattered unsuccessful looukp.xlsx.plot.png]

h|running insertion
h|running erasure
h|successful lookup
h|unsuccessful lookup

|===

=== GCC 12, x86


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/gcc-x86/Running insertion.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/gcc-x86/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x86/Running erasure.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/gcc-x86/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x86/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/gcc-x86/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x86/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/gcc-x86/Scattered unsuccessful looukp.xlsx.plot.png]

h|running insertion
h|running erasure
h|successful lookup
h|unsuccessful lookup

|===

=== Clang 15, x86


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/clang-x86/Running insertion.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-x86/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x86/Running erasure.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-x86/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x86/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-x86/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x86/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/clang-x86/Scattered unsuccessful looukp.xlsx.plot.png]

h|running insertion
h|running erasure
h|successful lookup
h|unsuccessful lookup

|===

=== Visual Studio 2022, x86


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/vs-x86/Running insertion.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/vs-x86/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x86/Running erasure.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/vs-x86/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x86/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/vs-x86/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x86/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link= _images/benchmarks-flat_map/vs-x86/Scattered unsuccessful looukp.xlsx.plot.png]

h|running insertion
h|running erasure
h|successful lookup
h|unsuccessful lookup

|===

== boost::concurrent_(flat|node)_map

All benchmarks were created using:

* `https://spec.oneapi.io/versions/latest/elements/oneTBB/source/containers/concurrent_hash_map_cls.html[oneapi::tbb::concurrent_hash_map^]<int, int>`
* `https://github.com/greg7mdp/gtl/blob/main/docs/phmap.md[gtl::parallel_flat_hash_map^]<int, int>` with 64 submaps
* `boost::concurrent_flat_map<int, int>`
* `boost::concurrent_node_map<int, int>`

The source code can be https://github.com/boostorg/boost_unordered_benchmarks/tree/boost_concurrent_flat_map[found here^].

The benchmarks exercise a number of threads _T_ (between 1 and 16) concurrently performing operations
randomly chosen among **update**, **successful lookup** and **unsuccessful lookup**. The keys used in the
operations follow a https://en.wikipedia.org/wiki/Zipf%27s_law#Formal_definition[Zipf distribution^]
with different _skew_ parameters: the higher the skew, the more concentrated are the keys in the lower values
of the covered range.

`boost::concurrent_flat_map` and `boost::concurrent_node_map` are exercised using both regular and xref:concurrent.adoc#concurrent_bulk_visitation[bulk visitation]:
in the latter case, lookup keys are buffered in a local array and then processed at
once each time the buffer reaches `xref:reference/concurrent_flat_map.adoc#concurrent_flat_map_constants[bulk_visit_size]`.

=== GCC 12, x64


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.01.png]
|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.5.png]
|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.99.png]

h|500k updates, 4.5M lookups +
skew=0.01
h|500k updates, 4.5M lookups +
skew=0.5
h|500k updates, 4.5M lookups +
skew=0.99
|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.01.png]
|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.5.png]
|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.99.png]

h|5M updates, 45M lookups +
skew=0.01
h|5M updates, 45M lookups +
skew=0.5
h|5M updates, 45M lookups +
skew=0.99
|===

=== Clang 15, x64


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.01.png]
|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.5.png]
|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.99.png]

h|500k updates, 4.5M lookups +
skew=0.01
h|500k updates, 4.5M lookups +
skew=0.5
h|500k updates, 4.5M lookups +
skew=0.99
|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.01.png]
|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.5.png]
|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.99.png]

h|5M updates, 45M lookups +
skew=0.01
h|5M updates, 45M lookups +
skew=0.5
h|5M updates, 45M lookups +
skew=0.99
|===

=== Visual Studio 2022, x64


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.01.png]
|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.5.png]
|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.99.png]

h|500k updates, 4.5M lookups +
skew=0.01
h|500k updates, 4.5M lookups +
skew=0.5
h|500k updates, 4.5M lookups +
skew=0.99
|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.01.png]
|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.5.png]
|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.99.png]

h|5M updates, 45M lookups +
skew=0.01
h|5M updates, 45M lookups +
skew=0.5
h|5M updates, 45M lookups +
skew=0.99
|===

=== Clang 12, ARM64


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.01.png]
|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.5.png]
|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.99.png]

h|500k updates, 4.5M lookups +
skew=0.01
h|500k updates, 4.5M lookups +
skew=0.5
h|500k updates, 4.5M lookups +
skew=0.99
|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.01.png]
|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.5.png]
|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.99.png]

h|5M updates, 45M lookups +
skew=0.01
h|5M updates, 45M lookups +
skew=0.5
h|5M updates, 45M lookups +
skew=0.99
|===

=== GCC 12, x86


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.01.png]
|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.5.png]
|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.99.png]

h|500k updates, 4.5M lookups +
skew=0.01
h|500k updates, 4.5M lookups +
skew=0.5
h|500k updates, 4.5M lookups +
skew=0.99
|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.01.png]
|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.5.png]
|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.99.png]

h|5M updates, 45M lookups +
skew=0.01
h|5M updates, 45M lookups +
skew=0.5
h|5M updates, 45M lookups +
skew=0.99
|===

=== Clang 15, x86


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.01.png]
|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.5.png]
|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.99.png]

h|500k updates, 4.5M lookups +
skew=0.01
h|500k updates, 4.5M lookups +
skew=0.5
h|500k updates, 4.5M lookups +
skew=0.99
|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.01.png]
|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.5.png]
|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.99.png]

h|5M updates, 45M lookups +
skew=0.01
h|5M updates, 45M lookups +
skew=0.5
h|5M updates, 45M lookups +
skew=0.99
|===

=== Visual Studio 2022, x86


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.01.png]
|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.5.png]
|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.99.png]

h|500k updates, 4.5M lookups +
skew=0.01
h|500k updates, 4.5M lookups +
skew=0.5
h|500k updates, 4.5M lookups +
skew=0.99
|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.01.png]
|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.5.png]
|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link= _images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.99.png]

h|5M updates, 45M lookups +
skew=0.01
h|5M updates, 45M lookups +
skew=0.5
h|5M updates, 45M lookups +
skew=0.99
|===