[Mono-dev] [PATCH] Speed up ByteEncoding.GetString()

Kornél Pál kornelpal at gmail.com
Tue Jun 13 17:06:11 EDT 2006


I committed the patch. Note according to my test result this implementation
is about three times faster than the previous one so I consider it to be
obvious improvement. Of course this only affects ByteEncoding.GetString()
but other encodings were not using StringBuilder so they are faster altough
they could be improved using unsafe code but that requires some
infrastructural changes in I18N.

For the referenced bug:

When calling for example MethodInfo.Invoke or Delegate.CreateDelegate 
without ReflectionPermissionFlag.MemberAccess permission 
MethodAccessException has to be thrown. But I don't think that this is a 
mysterious bug. This behaviour is documented on MSDN and if you search for 
MethodAccessException you will find the methods that throw 
MethodAccessException with the description when they trow it.

Anyway the bug in Mono is that it doesn't enforce this check not that it 
grants ReflectionPermissionFlag.MemberAccess permission to code. If  we 
grant ReflectionPermissionFlag.MemberAccess permission (or full trust) to 
class library assemblies we can use reflection safely.


----- Original Message ----- 
From: "Atsushi Eno" <atsushi at ximian.com>
To: "Kornél Pál" <kornelpal at gmail.com>
Cc: <mono-devel-list at lists.ximian.com>
Sent: Tuesday, June 13, 2006 4:10 PM
Subject: Re: [Mono-dev] [PATCH] Speed up ByteEncoding.GetString()

>I see no problem on this patch, so feel free to go ahead, though the
> improvement is not obvious now. But it would be faster in general
> cases.
> Just an extra note, see bug #70841 to see concrete nonpublic method
> access problem that Miguel was worried.
> Atsushi Eno
> Kornél Pál wrote:
>> Is this patch OK to commit?
>> Kornél
>> ----- Original Message ----- From: "Kornél Pál" <kornelpal at gmail.com>
>> To: "Miguel de Icaza" <miguel at ximian.com>
>> Cc: <mono-devel-list at lists.ximian.com>
>> Sent: Friday, June 09, 2006 2:24 PM
>> Subject: Re: [Mono-dev] [PATCH] Speed up ByteEncoding.GetString()
>>> OK, now I understan your problem.
>>> Please review this modified patch.
>>> Kornél
>>> ----- Original Message ----- From: "Miguel de Icaza" <miguel at ximian.com>
>>> To: "Kornél Pál" <kornelpal at gmail.com>
>>> Cc: <mono-devel-list at lists.ximian.com>
>>> Sent: Friday, June 09, 2006 2:01 PM
>>> Subject: Re: [Mono-dev] [PATCH] Speed up ByteEncoding.GetString()
>>>> Hello,
>>>>> Invoking non-public methods using SRE is widely used by our class
>>>>> library,
>>>>> it is supported by the ECMA standards so I don't really understand
>>>>> what
>>>>> you
>>>>> mean on "access to internal methods will at some point broken".
>>>> As I said, this might be something that we will fix in the future, and
>>>> although it works today, it does not mean it will work today, I do not
>>>> want to add more dependencies that might prevent us from fixing it in
>>>> the future.
>>>> Besides, poking at string internals is not something am very excited
>>>> about supporting nor encouraging.  The last time we did something
>>>> "unsafe" like this, it was reviewed over and over, and it turned out to
>>>> be buggy, it took months to track the mysterious bug because the
>>>> conditions were very hard to reproduce.
>>>>> Note that even using "new string ((char) 0, length)" is faster than
>>>>> the
>>>>> current implementation.
>>>> That part of the patch is fine with me.
>>>> Miguel
>> ------------------------------------------------------------------------
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