Re: [Openexr-devel] Compiling on MinGW

[Giuseppe Rota]

Thankyou Florian, I'll look into it.
Giuseppe

On 12/21/06, Florian Kainz <address@hidden> wrote:

Hi Guiseppe,

the problem you are having could be caused by the build scripts.  I've
never used minGW, so I can't really debug this myself.  Assuming I can
somehow create an environment on Linux where pthreads are unavailable,
I might be able reproduce the problem, but I won't be able to work on
this for a while.

Which parts of the IlmThread library are compiled (dummy implementation,
Posix threads or Windows threads) is governed by a couple of compile-time
flags.  For example, IlmThreadMutex.cpp looks like this:

     #include "IlmBaseConfig.h"

     #if !defined (_WIN32) && !(_WIN64) && !(HAVE_PTHREAD)

     #include "IlmThreadMutex.h "

     namespace IlmThread {

     Mutex::Mutex () {}
     Mutex::~Mutex () {}
     void Mutex::lock () const {}
     void Mutex::unlock () const {}

     } // namespace IlmThread

     #endif

You may want to try hard-wiring the settings of those flags.
For example in IlmThreadMutex.cpp, replace

     #if !defined (_WIN32) && !(_WIN64) && !(HAVE_PTHREAD)

with

     #if 1

replace the corresponding lines in IlmThreadMutexPosix.cpp
and IlmThreadMutexWindows.cpp with

     #if 0

After you re-compile, the mutex-related symbols should no
longer be missing.  If this works, fix the rest of IlmThread
in a similar way.

Florian



Giuseppe Rota wrote:
> It seems like the problem is in the building of IlmThread itself. We
> cannot complete the linking step: there are a lot of undefined
> references (see attachment). Could this be a problem with the autotools,
> maybe?
> As far as using the precompiled DLLs is concerned, I tried but I was not
> able to link against them: I had the same problem with the win32 native
> build of ImageMagick, and they told me that it was a problem of name
> mangling of the compiler.
> Giuseppe
>
> On 12/20/06, *Florian Kainz* <address@hidden <mailto:address@hidden>> wrote:
>
>     I must admit that I don't know anything about minGW, but maybe
>     the following helps:
>
>     The IlmThread library will be built even if you disable threading.
>     It will contain dummy implementations for threads, mutexes and
>     semaphores.  Creating a thread always throws an exception, and
>     attempts to lock mutexes and semaphores always succeed.
>
>     The IlmImf library should work even with the dummy IlmThread
>     implementation, as long as you don't enable threading.  You should
>     be able to compile and link the IlmImfTest executable.  When you
>     run the executable, any tests that involve multithreading will
>     fail, but that doesn't necessarily mean that the IlmImf library
>     is broken.  The tests should run to completion if you comment out
>     all calls to setGlobalThreadCount() in test*.cpp.
>
>     Alternatively, can your application be linked against DLLs from a
>     native Windows build?  OpenEXR comes with Visual C++ project files,
>     and threading does work on Windows.
>
>     Florian
>
>
>
>     Paul Gregory wrote:
>      > Hi All,
>      >
>      > I've been trying to get OpenEXR to compile on MinGW for some time
>     now so
>      > that we (the Aqsis team) can release a version of Aqsis that
>     supports
>      > OpenEXR on both Windows and Posix. However, as others have found
>     on this
>      > list, it doesn't seem that OpenEXR is well setup to compile on MinGW.
>      >
>      > The main stumbling block I've hit so far is threading, I've tried to
>      > fool it into using the Win32 threading code, no joy, I've tried to
>      > install and get it to use the Win32 port of pthreads, again no
>     joy. The
>      > wierdest of all is that --disable-threading doesn't actually seem to
>      > disable threading, it still tries and fails to build the IlmThread
>      > project of ilmbase. I've hit these problems with both the stable
>     1.4.0
>      > source archive, and the newer split 1.5.0 of OpenEXR and 0.9.0
>     IlmBase
>      > source archive.
>      >
>      > If anyone has any suggestions on how to get this all to compile on
>      > MinGW/MSYS, it would be most appreciated.
>      >
>      > Thanks
>      >
>      > --
>      > Paul Gregory
>      > http://www.aqsis.org
>      >
>      >
>      >
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