Re: [boost] [interprocess] maximum length for names of mutexes, memory segments etc.

Subject: Re: [boost] [interprocess] maximum length for names of mutexes, memory segments etc.
From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2008-12-04 12:56:31

JOAQUIN M. LOPEZ MUÑOZ wrote:
> A component of Boost.Flyweight called intermodule_holder internally
> uses some Boost.Interprocess objects with very long names intended
> to guarantee sistem-wide uniqueness. For instance, this is how such
> an internal mutex can be named (87 chars):
> 
> boost_flyweight_intermodule_holder_mutex_5660_601342046_2913549788_3054690985_591945496
> 
> Alas seems like 87 chars is too much in some platforms like NetBSD:
> 
>   terminate called after throwing an instance of 'boost::interprocess::interprocess_exception'
>     what():  File name too long
> 
> See http://tinyurl.com/6m693p . This problem also shows in some of
> Boost.Inteprocess own tests for NetBSD.
> Is there any maximum length we can safely commit to across allplatforms?
> (docs are silent wrt this).

I don't know if a portable scheme can be easily deduced. Just to be 
curious, does the C++ standard say anything about path or file name 
lengths? Maybe we should follow the same way. The path length depends on 
the filesystem type so finding a common scheme might be pretty 
difficult. Some operating system (embedded mainly) named objects require 
pretty short names, so I don't know what could be a portable length.

Regards,

Ion