Garbage collection in D

[Robert Fraser]

Sam Hu wrote:
> bearophile Wrote:
> 
>> I have tried the new JavaVM on Win, that optionally performs escape analysis, and the results are nice:
>>
>> Timings, N=100_000_000, Windows, seconds:
>>   D 1:  40.20 DMD
>>   D 2:  21.83 DMD
>>   D 2:  18.80 DMD, struct + scope
>>   C++:  18.06
>>   D 1:   8.47 DMD
>>   D 2:   7.41 DMD + scope
>>   Java:  1.84 V.1.6.0_14, -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC
>>   Java   1.78 -server
>>   Java:  1.44
>>   Java:  1.38 V.1.6.0_14
>>   Java:  0.28 V.1.6.0_14, -server -XX:+DoEscapeAnalysis
>>   
>> Timings, N=100_000_000, Pubuntu, seconds:
>>   D 1:  25.7  LDC
>>   C++:   6.87
>>   D 1:   2.67 LDC + scope
>>   Java:  1.49
>>
>> Bye,
>> bearophile
> 
> Sorry for my stepping in...
> 
> What does this result mean?Does it mean D is slower than Java and C++ is also slower than Java?Or that's true just under  certain circumstance?
> I am really confused and really appreicate if any further explanation.
> 
> 
> Regards,
> Sam

It suggests that for dynamic allocation of many small objects via "new", 
Java is an order of magnitude faster than C++, which in turn is slightly 
faster than D.