On 08.09.2013 14:17, Bart wrote:
On 9/8/13, Tomas Hajny <xhaj...@hajny.biz> wrote:
Why do you believe that ExpandFilename is not threadsafe (on Windows or
any other platform)?
..
The only platform specific part inside
ExpandFilename is a call to GetDir function retrieving the current
directory. If that is not 'threadsafe' by itself (on Windows), then your
statement is correct,
And that is exactly the point.
GetDir calls GetCurentDirectory and MS says (see:
http://msdn.microsoft.com/en-us/library/windows/desktop/aa364934%28v=vs.85%29.aspx)
that multithreaded applications should not call GetCurrentDirectory.
The problem is not GetCurrentDirectory itself (this function and
SetCurrentDirectory use the process's PEB lock to access the current
directory which is stored inside the PEB as well), but that different
threads could call SetCurrentDirectory with different values and thus a
thread who expected the current directory to be a specific one might
resolve a relative path (by using another WinAPI function) using a
current directory set by a different thread.
So this can not be solved by using a lock inside ExpandFilename and
might happen on other systems as well as long as the current directory
is not stored per thread.
Regards,
Sven
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