Issue #10212 has been updated by Eric Wong.


 rb_env_t may use a flexible array, helps a little even on my busy system:
 
 http://80x24.org/misc/m/1410173063-19208-1-git-send-email-e%4080x24.org.txt
 
 trunk   135.18708946416155
 trunk   123.50244501209818
 trunk   133.2718793260865
 fa      109.13581056008115
 fa      116.52121020900086
 fa      114.37961085699499
 
 -----------------------------------------------------------
 raw data:
 
 [["app_lc_fizzbuzz",
   [[135.18708946416155, 123.50244501209818, 133.2718793260865],
    [109.13581056008115, 116.52121020900086, 114.37961085699499]]]]
 
 Elapsed time: 732.008122514 (sec)
 -----------------------------------------------------------
 benchmark results:
 minimum results in each 3 measurements.
 Execution time (sec)
 name    trunk   fa
 app_lc_fizzbuzz 123.502 109.136
 
 Speedup ratio: compare with the result of `trunk' (greater is better)
 name    fa
 app_lc_fizzbuzz 1.132

----------------------------------------
Bug #10212: MRI is not for lambda calculus
https://bugs.ruby-lang.org/issues/10212#change-48724

* Author: Koichi Sasada
* Status: Open
* Priority: Normal
* Assignee: Koichi Sasada
* Category: 
* Target version: current: 2.2.0
* ruby -v: ruby 2.2.0dev (2014-08-21 trunk 47241) [x86_64-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
 # title is joke.

I added benchmark/bm_lc_fizzbuzz.rb which solve fizz buzz program by lambda calculus.
http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=47447

(This program is closly described by ["Understanding Computation"] (http://computationbook.com/) by Tom Stuart)
([Japanese translation of this book] (http://www.oreilly.co.jp/books/9784873116976/) will be published soon)

The results of this program are:

```
jruby 1.7.12 (1.9.3p392) 2014-04-15 643e292 on OpenJDK 64-Bit Server VM 1.7.0_65-b32 [linux-amd64]
real    0m26.648s
user    0m30.091s
sys     0m4.369s

mruby 89e9df26819b9555fb790a16662f4ad2b9cbb2e2
real    0m27.145s
user    0m27.110s
sys     0m0.012s

ruby 2.2.0dev (2014-08-21 trunk 47241) [x86_64-linux]
real    1m54.648s
user    1m54.512s
sys     0m0.028s
```

It is clear that MRI is too slow.

I haven't dig details, but maybe it is because of GC perforamance. Because Proc (and Env) objects are wb-unprotected, such objects are marked on every minor GC.

This problem is not critical because MRI is not for lambda calculus :p but we can improve about it.




-- 
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