«

Hi,

I hope, that my topic is not off-topic.
I try to compile with g++ 4.0.1 a multithreaded library. On MS Visual
Studio I must set the crt-libs for multithreaded.
Do I need this for g++? Is there a falg (linker / compiler) for using
multithread?

Thanks

Phil

Hi,

Philipp Kraus wrote:
> I hope, that my topic is not off-topic.
> I try to compile with g++ 4.0.1 a multithreaded library. On MS Visual
> Studio I must set the crt-libs for multithreaded.
> Do I need this for g++? Is there a falg (linker / compiler) for using
> multithread?

this is platform dependent, even with gcc. So there is no general answer.

You have to check informations about your platform or ask in a platform
related group.


Marcel

Am 24.08.2010 11:32, schrieb Philipp Kraus:
> Hi,
>
> I hope, that my topic is not off-topic.
> I try to compile with g++ 4.0.1 a multithreaded library. On MS Visual
> Studio I must set the crt-libs for multithreaded.
> Do I need this for g++? Is there a falg (linker / compiler) for using
> multithread?
>
> Thanks
>
> Phil
>

On most Unixes (including Mac OSX) you have to use -pthread für
compiling and linking.

Lars

On 8/24/2010 5:32 AM, Philipp Kraus wrote:
> I hope, that my topic is not off-topic.
> I try to compile with g++ 4.0.1 a multithreaded library. On MS Visual
> Studio I must set the crt-libs for multithreaded.
> Do I need this for g++? Is there a falg (linker / compiler) for using
> multithread?

Just to let you know, there is a hierarchy of newsgroups, whose name
stars with 'gnu.', for questions specific to those products. There is,
AFAIK, a subhierarchy 'gnu.g++.*', but I don't follow it closely to know
how useful (or useless) it might be.

And, generally speaking, questions on specific compilers, their options,
their libraries, command line format, etc., *are* off-topic.

V
--
I do not respond to top-posted replies, please don't ask

On Tue, 2010-08-24, Lars Tetzlaff wrote:
> Am 24.08.2010 11:32, schrieb Philipp Kraus:
>> Hi,
>>
>> I hope, that my topic is not off-topic.
>> I try to compile with g++ 4.0.1 a multithreaded library. On MS Visual
>> Studio I must set the crt-libs for multithreaded.
>> Do I need this for g++? Is there a falg (linker / compiler) for using
>> multithread?
>
> On most Unixes (including Mac OSX) you have to use -pthread für
> compiling and linking.

I don't know MacOS but I know the others, and I believe you're wrong.
You have to link with the Pthreads library (-lpthread) to use the
Pthreads functions, but there's nothing remarkable about that.

There was in the distant past a #define _REENTRANT which prepared the
C standard library for multithreaded use ... unsure which systems need
it today, but that's easy to google for.

/Jorgen

--
// Jorgen Grahn <grahn@ Oo o. . .
\X/ snipabacken.se> O o .

Am 25.08.2010 09:38, schrieb Jorgen Grahn:
> On Tue, 2010-08-24, Lars Tetzlaff wrote:
>> Am 24.08.2010 11:32, schrieb Philipp Kraus:
>>> Hi,
>>>
>>> I hope, that my topic is not off-topic.
>>> I try to compile with g++ 4.0.1 a multithreaded library. On MS Visual
>>> Studio I must set the crt-libs for multithreaded.
>>> Do I need this for g++? Is there a falg (linker / compiler) for using
>>> multithread?
>>
>> On most Unixes (including Mac OSX) you have to use -pthread für
>> compiling and linking.
>
> I don't know MacOS but I know the others, and I believe you're wrong.
> You have to link with the Pthreads library (-lpthread) to use the
> Pthreads functions, but there's nothing remarkable about that.
>
> There was in the distant past a #define _REENTRANT which prepared the
> C standard library for multithreaded use ... unsure which systems need
> it today, but that's easy to google for.
>
> /Jorgen
>

No, -pthread implies -lpthread but also switches the compiler to
threaded mode (i.e. errno is thread local).

From info g++:

`-pthread'
Adds support for multithreading with the "pthreads" library. This
option sets flags for both the preprocessor and linker.



Lars

On Wed, 2010-08-25, Lars Tetzlaff wrote:
> Am 25.08.2010 09:38, schrieb Jorgen Grahn:
>> On Tue, 2010-08-24, Lars Tetzlaff wrote:
>>> Am 24.08.2010 11:32, schrieb Philipp Kraus:
>>>> Hi,
>>>>
>>>> I hope, that my topic is not off-topic.
>>>> I try to compile with g++ 4.0.1 a multithreaded library. On MS Visual
>>>> Studio I must set the crt-libs for multithreaded.
>>>> Do I need this for g++? Is there a falg (linker / compiler) for using
>>>> multithread?
>>>
>>> On most Unixes (including Mac OSX) you have to use -pthread für
>>> compiling and linking.
>>
>> I don't know MacOS but I know the others, and I believe you're wrong.
>> You have to link with the Pthreads library (-lpthread) to use the
>> Pthreads functions, but there's nothing remarkable about that.
>>
>> There was in the distant past a #define _REENTRANT which prepared the
>> C standard library for multithreaded use ... unsure which systems need
>> it today, but that's easy to google for.
>>
>> /Jorgen
>>
>
> No, -pthread implies -lpthread but also switches the compiler to
> threaded mode (i.e. errno is thread local).
>
> From info g++:
>
> `-pthread'
> Adds support for multithreading with the "pthreads" library. This
> option sets flags for both the preprocessor and linker.

Ah, sorry. I note though that that's an "IBM RS/6000 and PowerPC"
option, and also on SPARC. So I guess it boils down to what someone
else suggested: RTFM for your compiler, standard library and
architecture.

/Jorgen

--
// Jorgen Grahn <grahn@ Oo o. . .
\X/ snipabacken.se> O o .

On 25/08/10 08:38, Jorgen Grahn wrote:
> On Tue, 2010-08-24, Lars Tetzlaff wrote:
>> Am 24.08.2010 11:32, schrieb Philipp Kraus:
>>> Hi,
>>>
>>> I hope, that my topic is not off-topic.
>>> I try to compile with g++ 4.0.1 a multithreaded library. On MS Visual
>>> Studio I must set the crt-libs for multithreaded.
>>> Do I need this for g++? Is there a falg (linker / compiler) for using
>>> multithread?
>>
>> On most Unixes (including Mac OSX) you have to use -pthread für
>> compiling and linking.
>
> I don't know MacOS but I know the others, and I believe you're wrong.
> You have to link with the Pthreads library (-lpthread) to use the
> Pthreads functions, but there's nothing remarkable about that.

With some compilers (don't remember whether it was gcc or Sun compiler)
linking explicitly with -lpthread meant using the old threads library,
as opposed to using -pthread or -mt for linking.

--
Max