Does utime do what you need?

the help says :-

For example, this code has the same effect as the Unix touch(1) comman
+d when
the files already exist and belong to the user running the program:

#!/usr/bin/perl
$atime = $mtime = time;
utime $atime, $mtime, @ARGV;
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Don't know about thread safety though, but why would you care ?