_TempFile UDF - possible bug

[LoWang]

Hello I have noticed a very strange behavior of this function - it seems to be outputting the SAME result when you run two concurrent scripts and they happen to call this function in the same time!

It took me a while to see what's happening but it is true - my two scripts both log messages in one logfile while running so I set up logging of the generated _TempFile filename they were going to use and it was the same several times. It seems it does not depend on system time seconds value, because I generated 5 filenames during one second and 2 pairs were the same and one was different. What shall I do? I think I will have to use some fixed filename for every file operation instead of _TempFile since it is not reliable when you run two processes using it :-\

[KaFu]

Use a script specific $s_FilePrefix.

[ProgAndy]

Try to use GetTempFileName

[jchd]

Use the PID as prefix, like:

$tempfn = _TempFile(@TempDir, @AutoitPID)

It should work around. You should perhaps try to make a reproduce example script. After confirmation post a ticket asking that the function be changed to incorporate the PID within the filename before testing for existence.

Anyway, that should bring our attention to the fact that the source of entropy used inside Random in not good enough and not resistant to parallel use in distinct processes. Perhaps using PID and some memory base address of process or similar value would help having a more random Random. I believe the underlying function itself is well beyond doubt; the culprit must be the seed used and the unsufficiently small granularity of timer(s).