Experiment: Linked list for Context

[fbogsany]

bogsanyi@franciss-mbp benchmarks % bundle exec ruby context_bench.rb
Allocations -------------------------------------
linked list with_value
                           4/0  alloc/ret        0/0  strings/ret
    array with_value       4/1  alloc/ret        0/0  strings/ret
Warming up --------------------------------------
linked list with_value
                       103.622k i/100ms
    array with_value   109.858k i/100ms
Calculating -------------------------------------
linked list with_value
                          1.336M (± 0.4%) i/s -      6.735M
    array with_value      1.452M (± 0.3%) i/s -      7.360M

Comparison:
    array with_value:  1452403.1 i/s
linked list with_value:  1335513.3 i/s - 1.09x slower

Allocations -------------------------------------
linked list with_values
                           3/3  alloc/ret        0/0  strings/ret
   array with_values       2/0  alloc/ret        0/0  strings/ret
Warming up --------------------------------------
linked list with_values
                       113.765k i/100ms
   array with_values   123.378k i/100ms
Calculating -------------------------------------
linked list with_values
                          1.520M (± 0.6%) i/s -      7.622M
   array with_values      1.634M (± 0.8%) i/s -      8.266M

Comparison:
   array with_values:  1633881.6 i/s
linked list with_values:  1519551.6 i/s - 1.08x slower

Allocations -------------------------------------
linked list with_value recursive
                          30/3  alloc/ret        0/0  strings/ret
array with_value recursive
                          20/0  alloc/ret        0/0  strings/ret
Warming up --------------------------------------
linked list with_value recursive
                        13.911k i/100ms
array with_value recursive
                        15.145k i/100ms
Calculating -------------------------------------
linked list with_value recursive
                        146.918k (± 0.4%) i/s -    737.283k
array with_value recursive
                        156.918k (± 0.7%) i/s -    787.540k

Comparison:
array with_value recursive:   156917.5 i/s
linked list with_value recursive:   146917.6 i/s - 1.07x slower

With yjit:

bogsanyi@franciss-mbp benchmarks % bundle exec ruby --yjit context_bench.rb
Allocations -------------------------------------
linked list with_value
                           4/0  alloc/ret        0/0  strings/ret
    array with_value       4/1  alloc/ret        0/0  strings/ret
Warming up --------------------------------------
linked list with_value
                       170.330k i/100ms
    array with_value   187.176k i/100ms
Calculating -------------------------------------
linked list with_value
                          2.940M (± 0.4%) i/s -     14.819M
    array with_value      3.470M (± 1.1%) i/s -     17.407M

Comparison:
    array with_value:  3470179.8 i/s
linked list with_value:  2939828.0 i/s - 1.18x slower

Allocations -------------------------------------
linked list with_values
                           3/0  alloc/ret        0/0  strings/ret
   array with_values       2/0  alloc/ret        0/0  strings/ret
Warming up --------------------------------------
linked list with_values
                       185.121k i/100ms
   array with_values   202.576k i/100ms
Calculating -------------------------------------
linked list with_values
                          3.277M (± 1.4%) i/s -     16.476M
   array with_values      4.054M (± 0.9%) i/s -     20.460M

Comparison:
   array with_values:  4054172.0 i/s
linked list with_values:  3276817.5 i/s - 1.24x slower

Allocations -------------------------------------
linked list with_value recursive
                          30/0  alloc/ret        0/0  strings/ret
array with_value recursive
                          20/0  alloc/ret        0/0  strings/ret
Warming up --------------------------------------
linked list with_value recursive
                        25.197k i/100ms
array with_value recursive
                        29.579k i/100ms
Calculating -------------------------------------
linked list with_value recursive
                        271.735k (± 0.6%) i/s -      1.361M
array with_value recursive
                        316.777k (± 0.9%) i/s -      1.597M

Comparison:
array with_value recursive:   316777.4 i/s
linked list with_value recursive:   271735.4 i/s - 1.17x slower

[fbogsany]

This was an experiment to help with open-telemetry/opentelemetry-ruby-contrib#772. The performance impact is significant enough that we shouldn't proceed with this.