From: Robert Klemme <shortcutter@...>
Date: 2007-06-12T23:25:04+09:00
Subject: Re: Benchmark segfault [Was: Array#inject to create a hash versus   Hash[*array.collect{}.flatten] ]

On 12.06.2007 16:16, Florian Frank wrote:
> Robert Klemme wrote:
>> I believe it's the star operator:
>>
>> 13:10:22 [Temp]: ruby -e 'Hash[*Array.new(ARGV.shift.to_i) ]' 1000000
>> 13:10:35 [Temp]: ruby -e 'Hash[*Array.new(ARGV.shift.to_i) ]' 10000000
>> -e:1: [BUG] Segmentation fault
>> ruby 1.8.6 (2007-03-13) [i386-cygwin]
>>
>> Aborted (core dumped)
>> 13:10:39 [Temp]: ruby -e 'def f(*a) end; f(*Array.new(ARGV.shift.to_i))'
>> 1000000
>> 13:11:09 [Temp]: ruby -e 'def f(*a) end; f(*Array.new(ARGV.shift.to_i))'
>> 10000000
>> -e:1: [BUG] Segmentation fault
>> ruby 1.8.6 (2007-03-13) [i386-cygwin]
>>
>> Aborted (core dumped)
>> 13:11:14 [Temp]: uname -a
>> CYGWIN_NT-5.2-WOW64 PDBXPWSRK38 1.5.24(0.156/4/2) 2007-01-31 10:57 i686
>> Cygwin
>> 13:11:36 [Temp]: ruby --version
>> ruby 1.8.6 (2007-03-13 patchlevel 0) [i386-cygwin]
> 
> The reason for this problem is, that the stack is used to pass A LOT of
> arguments to the Hash.[] method. If the stack size of the executed process isn't
> big enough (check your resource limits), this can lead to crashes.

That was what I was guessing.  However, I haven't enough insight to 
verify.  There is at least one point that causes me doubt: the array can 
be handled and stored like any other array, so it should be on the heap 
(or it is implicitly moved there).

Kind regards

	robert