in reply to Re^2: File::Temp painfully slow under Cygwin
in thread File::Temp painfully slow under Cygwin

Get Devel::Trace and try  perl -d:Trace -e ' require File::Temp; ' and try to find where it hangs

Replies are listed 'Best First'.
Re^4: File::Temp painfully slow under Cygwin
by dds (Novice) on Jul 09, 2013 at 13:18 UTC
    I think I nailed down the problem's cause. A simpler test case is
    perl -e 'use Cwd; print getcwd'
    At some point this issues the following Cygwin calls
      168 4607616 main perl 9268 mount_info::conv_to_win32_path: src_path //Cwd.dll, dst \\Cwd.dll, flags 0x2, rc 0
      170 4607786 main perl 9268 build_fh_pc: fh 0x61276450, dev 000000C2
      937 4608723 WNetOpenEnum perl 9268 cygthread::stub: thread 'WNetOpenEnum', id 0x1A58, stack_ptr 0x109AD40
    --- Process 9268, exception 000006ba at 767DC41F
    2273000 6881723 main perl 9268 __set_errno: int stat_worker(path_conv&, stat*):1880 setting errno 2
    
    Note that //Cwd.dll is interpreted as a network path on Windows and that WNetOpenEnum takes two seconds to execute, before failing with an exception. Tracing the code gives
    $ perl -d:Trace -e 'use Cwd; print getcwd'
    >> -e:1: use Cwd; print getcwd
    >> /usr/lib/perl5/5.14/i686-cygwin-threads-64int/Cwd.pm:406:   *cwd = sub { &$orig_cwd() }
    
    and this seems to be related to the following code.
    if ($^O eq 'cygwin') {
      # We need to make sure cwd() is called with no args, because it's
      # got an arg-less prototype and will die if args are present.
      local $^W = 0;
      my $orig_cwd = \&cwd;
      *cwd = sub { &$orig_cwd() }
    }