Re: [boost] [shmem] Shmem version 0.9 available

From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2006-01-28 05:32:06

> When I tried to upgrade shmem 0.9 in vault I am failing to compile on
> Cygwin using gcc 3.4.4 with the following error message.
> 
> e:/boost/boost_1_33_1/boost/shmem/shared_memory.hpp:585: error: there are no
> arguments to `shm_open' that depend on a template parameter, so a
> declaration of `shm_open' must be available
> e:/boost/boost_1_33_1/boost/shmem/shared_memory.hpp:585: error: (if you use
> `-fpermissive', G++ will accept your code, but allowing the use of an
> undeclared name is deprecated)
> 
> I went a head and added the following two lines to shared_memory.hpp after
> which I was able to compile.

I didn't know that someone was trying to use this in cygwin! Last time I 
checked, cygwin had not PTHREAD_PROCESS_SHARED support so I thought 
Shmem couldn't work with cygwin. I'm wrong or has this changed?

You've said "I tried to upgrade shmem 0.9" so I suppose you have tested 
previous Shmem versions. What was the latest version of Shmem that you 
could compile?

I don't know much about cygwin but shared_memory.hpp header says:

#if (defined BOOST_WINDOWS) && !(defined BOOST_DISABLE_WIN32)
#  include <boost/shmem/sync/win32/win32_sync_primitives.hpp>
#else

#  ifdef BOOST_HAS_UNISTD_H
#    include <fcntl.h>        //O_CREAT, O_*...
#    include <sys/mman.h>     //mmap
#    include <unistd.h>       //ftruncate, close
#    include <semaphore.h>  //sem_t* family, SEM_VALUE_MAX
#    include <string>         //std::string
#    include <sys/stat.h>     //mode_t, S_IRWXG, S_IRWXO, S_IRWXU,
#  else
#    error Unknown platform
#  endif

So if you have calls to shm_open in the code the

#if (defined BOOST_WINDOWS) && !(defined BOOST_DISABLE_WIN32)

condition should be true and since you don't get

#    error Unknown platform

I suppose BOOST_HAS_UNISTD_H is true. And posix says

#    include <sys/mman.h>     //mmap

is enough to get shm_open and shm_unlink declarations. Can you 
investigate this a bit further?

Thanks,

Ion