Re: [B2-devel] problems caused(?) by recent patches

[Alexei S. <ale...@gm...>]

Charles,

Can you investigate the crashes with your precise timer patch?

-Alexei

On Thu, Jan 14, 2010 at 8:58 PM, Alexei Svitkine
<ale...@gm...> wrote:
> I've reverted the SDL audio patch.
>
> On Thu, Jan 14, 2010 at 3:06 PM, Ronald P. Regensburg
> <ron...@xs...> wrote:
>> In answer to the comments by Charles Srstka:
>>
>> About the precise timer patch:
>> The crash with the precise timer crash was not limited to PPC
>> machines. I noticed it myself on a PPC machine first while it did not
>> happen on my Intel machine. However, within 6 days after posting my
>> 18-10-2009 build I got in the SheepShaver forum four reports of the
>> crash, each at the very same moment in the startup process, one on a
>> PPC machine and three on a Intel machine. The 25-10-2009 build
>> (without the precise timer patch) solved the crash for myself on my
>> PPC machine as well as for the other reported PPC machine and for two
>> out of the three reported Intel machines. On the third reported Intel
>> machine the 25-10-2009 crashed with a SIGSEGV. That crash was resolved
>> by enabling "Ignore Illegal Memory Accesses" (ignoresegv true). Later,
>> there were a few more reports of SIGSEGV crashes on Intel machines
>> with the 25-10-2009 build that could be solved this way. So far, I got
>> one report of the 25-10-2009 build crashing with a SIGSEGV in Leopard
>> on a PPC machine, not yet solved nor understood.
>>
>> About the sdl-audio patch:
>> Probably best to simply remove the patch. In the original
>> pre-19-02-2009 BasiliskII/src/SDL/audio_sdl.cpp file the value for
>> audio_spec.samples is set to 4096, well within the recommended range.
>>
>> Ronald.
>>
>>
>> Op 14 jan 2010, om 17:11 heeft Charles Srstka het volgende geschreven:
>>
>>> On Jan 14, 2010, at 7:18 AM, Ronald P. Regensburg wrote:
>>>
>>>>
>>>> In Emaculation.com forums, Alexei Svitkine asked me to mail to this
>>>> list about patches I needed to revert before building SheepShaver
>>>> (and
>>>> BasiliskII) for Mac OS X in order to avoid problems.
>>>>
>>>>
>>>> The problems with the "precise timer patch" were discussed in the
>>>> basilisk-devel list between October 23 and October 28. Those problems
>>>> were the reason for me to make the 25-10-2009 build for
>>>> Emaculation.com within days after the 18-10-2009 build.
>>>>
>>>> In my last October 25 message to the basilisk-devel list I told which
>>>> files I used for the 25-10-2009 build to omit the "precise timer
>>>> patch" and the "sdl-audio patch".
>>>>
>>>> The "sdl-audio patch" apparently made sound for most users worse
>>>> rather than better. Users of both BasiliskII and SheepShaver builds
>>>> created after that patch was added, complained about the problems for
>>>> months and reported considerable improvement when I posted builds of
>>>> both without the patch. That happened before I joined this mailing
>>>> list. The problems were sound delays, stuttering, even skipping of
>>>> sounds. The problem was more serious in BasiliskII than in
>>>> SheepShaver.
>>>>
>>>> I do not know whether these patches actually cause the problems or
>>>> just make bugs in other parts of the code apparent.
>>>
>>> The crash with the precise timer patch was mostly limited to running
>>> the app on PPC machines if I remember correctly, wasn’t it? Since
>>> SheepShaver runs completely different code paths on PPC and Intel,
>>> with the PPC version running native code and the Intel using
>>> emulation, I can see how the change could have caused problems with
>>> one that would not have come up on the other. The best solution in
>>> this case may be to enable the precise timer patch only when
>>> building for Intel.
>>>
>>> The SDL audio patch, on the other hand, is simply ill-advised in my
>>> opinion. The docs for SDL recommend using a value between 512 and
>>> 8192 for the ‘samples’ field of an SDL_AudioSpec. The patch in the
>>> SheepShaver source sets it to 16384. The result is laggy audio. I
>>> think the patch was made to reduce the demands on processing power
>>> for older machines, but for those with modern hardware it seems to
>>> cause more problems than it solves.
>>>
>>> Charles
>>> ------------------------------------------------------------------------------
>>> Throughout its 18-year history, RSA Conference consistently attracts
>>> the
>>> world's best and brightest in the field, creating opportunities for
>>> Conference
>>> attendees to learn about information security's most important
>>> issues through
>>> interactions with peers, luminaries and emerging and established
>>> companies.
>>> http://p.sf.net/sfu/rsaconf-dev2dev
>>> _______________________________________________
>>> basilisk-devel mailing list
>>> bas...@li...
>>> https://lists.sourceforge.net/lists/listinfo/basilisk-devel
>>>
>>
>>
>> ------------------------------------------------------------------------------
>> Throughout its 18-year history, RSA Conference consistently attracts the
>> world's best and brightest in the field, creating opportunities for Conference
>> attendees to learn about information security's most important issues through
>> interactions with peers, luminaries and emerging and established companies.
>> http://p.sf.net/sfu/rsaconf-dev2dev
>> _______________________________________________
>> basilisk-devel mailing list
>> bas...@li...
>> https://lists.sourceforge.net/lists/listinfo/basilisk-devel
>>
>