[Python-Dev] Py_BEGIN_ALLOW_THREADS around readdir()?

Mon Apr 17 21:08:27 CEST 2006

On 17-apr-2006, at 20:50, Martin v. Löwis wrote:
> Ronald Oussoren wrote:
>> AFAIK readdir is only unsafe when multiple threads use the same 
>> DIR* at
>> the same time. The spec[1] seems to agree with me.
>> [1] : http://www.opengroup.org/onlinepubs/009695399/functions/ 
>> readdir.html
>> What specific sentence makes you think so? I see
>> "The readdir() interface need not be reentrant."
>> which seems to allow for an implementation that returns a static
> struct dirent.

A couple of lines down it says:
"The pointer returned by readdir() points to data which may be 
overwritten by another call to readdir() on the same directory 
stream. This data is not overwritten by another call to readdir() on 
a different directory stream."
This explicitly says that implementations cannot use a static dirent 
structure.
>> Of course, the most natural implementation associates the storage
> for the result with the DIR*, so it's probably not a real problem...

If this were a problem on some platform I'd expect it to be so 
ancient that it doesn't offer readdir_r either.
Ronald