Re: [boost] Some Boost.Filesystem problems

From: Beman Dawes (bdawes_at_[hidden])
Date: 2004-12-13 16:19:57

At 04:42 PM 12/12/2004, Ben Hutchings wrote:

 >I noticed that Boost.Filesystem doesn't use readdir_r to iterate over
 >directories, even if it is available, making that non-thread-safe.
 >There is a comment to this effect in operations_posix_windows.cpp.
 >
 >I've attached a patch that I believe will allow it to detect whether
 >readdir_r is available and to use it iff it is.  I have only tested this
 >on Linux with g++ 3.3, but I tried deliberately breaking the declaration
 >of readdir_r and verified that the code continues to work without it.

Interesting approach!

I guess the alternative is hand configuration, and that isn't very 
attractive. So let me take a look at your patch in detail and get back to 
you.

 >On a visual inspection some time back I also noted that there's no
 >special handling for empty root directories on Windows.  The problem
 >with these is that while even an empty directory normally has entries
 >for "." and "..", so that FindFirstFile can return something, root
 >directories on FAT volumes (and I think NTFS as well) do not have these
 >and Windows doesn't fake them, so FindFirstFile on an empty root returns
 >INVALID_HANDLE_VALUE.  Note that this only applies to real root
 >directories, not to the roots of drives that are mapped to
 >sub-directories using subst or file sharing.  I never got round to
 >checking whether the Boost code actually handles this or not, as I only
 >use Windows at work and we don't use Boost.Filesystem there.  Perhaps
 >someone could check that out?

I've got some code that should serve to check that out. I'll let you know.

 >  Unfortunately it's impractical to test
 >automatically, as empty volumes are hard to generate on demand!

That's one of the difficulties of the library; there are quite a few test 
cases which are difficult and/or expensive to create on demand for testing.

Thanks for you help,

--Beman