stdio performance in tango, stdlib, and perl

[Andrei Alexandrescu (See Website For Email)]

James Dennett wrote:
> Walter Bright wrote:
>> Bill Baxter wrote:
>>> James Dennett wrote:
>>>> Walter Bright wrote:
>>>> It might be harsh, but not entirely unjustified, to say
>>>> that the "conventional wisdom" of many communities of
>>>> programmers is a long, long way from being wise.  As
>>>> the community behind a language grows larger, there is
>>>> a natural tendency for it not to have some a density
>>>> of experts; if D amasses a million users it's a safe
>>>> bet than most of them won't be as sharp as the average
>>>> D user is today.
>> D bucks conventional wisdom in more than one way. There's a current
>> debate going on among people involved in the next C++ standardization
>> effort about whether to include garbage collection or not. The people
>> involved are arguably the top tier of C++ programmers.
>>
>> But still, there are one or two that repeat the conventional (and wrong)
>> wisdom about garbage collection. Such conventional wisdom is much more
>> common among the general population of C++ programmers.
> 
> Which "wrong" assertions are those?
> 
>>> I think there is a tendency to assume that APIs and languages which
>>> have (A) been around a long time and
>>> (B) been used by millions of people
>>> will probably be close to optimal.  It just makes sense that that
>>> would be the case.  Unfortunately, it's all too often just not true.
>> I just find it strange that C++, a language meant for building speedy
>> applications, would incorporate iostreams, which is slow, not thread
>> safe, and not exception safe.
> 
> I'm intrigued by your claim that IOStreams is not thread-safe;
> the IOStreams framework is thread-safe in the same way that
> the STL is thread-safe.  The one minor difference is that
> IOStreams exposes some global variables, which is unfortunate
> as they can easily be used in inappropriate ways in a
> multi-threaded environment.  Then again, that is unsurprising
> as C++ does not yet officially incorporate support for
> multi-threading.  Is there something deeper in IOStreams that
> you consider to be thread-unsafe, or is it just the matter of
> its global variables?

cout << a << b;

can't guarantee that a and b will be adjacent in the output. In contrast,

printf(format, a, b);

does give that guarantee. Moreover, that guarantee is not between 
separate threads in the same process, it's between whole processes! 
Guess which of the two is usable :o).

Btw, does tango provide such a guarantee for code such as Cout(a)(b)? 
 From the construct, my understanding is that it doesn't.


Andrei