[jira] [Commented] (GUACAMOLE-94) readdir_r is deprecated

["Michael Jumper (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/GUACAMOLE-94?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15439457#comment-15439457 ] 

Michael Jumper commented on GUACAMOLE-94:
-----------------------------------------

Well, clearly we need to address this somehow.

That said, I cannot fathom why glibc is taking it upon themselves to deprecate a standard function. The documented justification:

{quote}
It is expected that a future version of POSIX.1 will make readdir_r() obsolete, and require that readdir() be thread-safe when concurrently employed on different directory streams.
{quote}

seems twisted, since the key point is that the *current* standard does no such thing. It strikes me as odd that a libc implementation would intentionally break their previous compatibility with the actual existing standard, in the hope that their vision for a different standard will become reality and provide absolution.

Anyway, on to what this would mean for the guacamole-server source:

{quote}
In cases where multiple threads must read from the same directory stream, using readdir(3) with external synchronization is still preferable to the use of readdir_r(), for the reasons given in the points above.
{quote}

Using readdir() instead of readdir_r() will require adding additional synchronization to prevent client threads trampling each other during concurrent directory reads.

> readdir_r is deprecated
> -----------------------
>
>                 Key: GUACAMOLE-94
>                 URL: https://issues.apache.org/jira/browse/GUACAMOLE-94
>             Project: Guacamole
>          Issue Type: Bug
>          Components: RDP
>    Affects Versions: 0.9.9
>            Reporter: tomberek
>            Priority: Minor
>
> A function is now deprecated in /src/protocols/rdp/rdp_fs.c:
> http://man7.org/linux/man-pages/man3/readdir_r.3.html
> I get this during builds (note, I've got a Nix expression building this in a chroot'd sandbox each time):
> {code:none}
> ...
>   CC       guac_rdpdr/guacdr_la-rdpdr_fs_service.lo
>   CC       guac_rdpdr/guacdr_la-rdpdr_messages.lo
>   CC       guac_rdpdr/guacdr_la-rdpdr_printer.lo
>   CC       guac_rdpdr/guacdr_la-rdpdr_service.lo
>   CC       guacdr_la-rdp_fs.lo
> rdp_fs.c: In function 'guac_rdp_fs_read_dir':
> rdp_fs.c:563:5: error: 'readdir_r' is deprecated [-Werror=deprecated-declarations]
>      if (readdir_r(file->dir, &(file->__dirent), &result))
>      ^
> In file included from rdp_fs.h:44:0,
>                  from rdp_fs.c:25:
> /nix/store/8ic0jwg3p5vcwx52k4781n987hmv0bks-glibc-2.24-dev/include/dirent.h:183:12: note: declared here
>  extern int readdir_r (DIR *__restrict __dirp,
>             ^
> cc1: all warnings being treated as errors
> make[3]: *** [Makefile:1197: guacdr_la-rdp_fs.lo] Error 1
> make[3]: Leaving directory '/tmp/nix-build-guacamole-0.9.9.drv-0/incubator-guacamole-server-6c0862e82da8ee737ee655c7815b1851de6d0488-src/src/protocols/rdp'
> make[2]: *** [Makefile:736: all] Error 2
> make[2]: Leaving directory '/tmp/nix-build-guacamole-0.9.9.drv-0/incubator-guacamole-server-6c0862e82da8ee737ee655c7815b1851de6d0488-src/src/protocols/rdp'
> make[1]: *** [Makefile:474: all-recursive] Error 1
> make[1]: Leaving directory '/tmp/nix-build-guacamole-0.9.9.drv-0/incubator-guacamole-server-6c0862e82da8ee737ee655c7815b1851de6d0488-src'
> make: *** [Makefile:406: all] Error 2
> {code}



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