Re: [Boost-Users] Re: 1.30.0 - problem with filesystem lib

From: Russ Wood (rw99_at_[hidden])
Date: 2003-03-21 09:09:35

On Fri, 21 Mar 2003, Russell Hind wrote:

>I had the same problem with C++Builder 6 when first using the filesystem
>library.  The default builds for filesystem are single threaded.  If
>your application is multi-threaded, then you need to re-build the
>filesystem library with multi-threading (it uses mutexes somewhere (I
>think from smart_ptr but can't remember)).  If you use the
>single-threaded library, then you don't get the mutex, but the
>++operator is inlined and tries to lock it.  This causes a hang as the
>win32 light-weight mutex is stored as just an integer (long maybe), so
>the program just hangs waiting for it to be cleared.
>
>I have built four versions of the library
>
>libboost_filesystem.lib    - release, single-threaded
>libboost_filesystemd.lib   - debug, single-threaded
>libboost_filesystemmt.lib  - release, multi-threaded
>libboost_filesystemmtd.lib - debug, multi-threaded
>
>I use a #pragma int the code to link the appropriate lib depending on
>Borland's __MT__ define (and also if I want debugging or not)
>
>HTH
>
>Russell

That makes sense, thanks. It would be good if all four versions were
built by bjam, or if this was mentioned somewhere in the docs.

I wonder why it was decided to have locking on directory iterators at
all, seems a bit low level?

Thanks for your help

Russ