Your reply makes perfect sense. The parent runs for quite a long time and starts only under very specific circumstances. It's also working with some legacy logic, so it's hard to test. I have, however, modified the child to remove the 5 second time out from can_read(5) because the IO::Select docs say:

If "TIMEOUT" is not given and any handles are registered then the call will block.

I also added the line:

        my ($handle) = $select->can_read(5);
    
        $handle->blocking(1);

[download]

This had no effect either, presumably because the handle to \*STDIN had already been created. I also tried setting that handle to blocking(1) before any loops start, which also had no effect:


   my @handles    = $select->handles();
   $handles[0]->blocking(1);

[download]

I'm concerned that even if I set the read handle to block in the parent when open2() is called it still won't work. Perhaps I need both the write handle and read handle to block?

Forgive my IPC ignorance here, but what I'm trying does not seem to match what I've read and I tried to do an extremely thorough job of research and testing.

In reply to Re^2: Performance and CPU load: sysread, IO::Select and/or Storable::thaw by DBX
in thread Performance and CPU load: sysread, IO::Select and/or Storable::thaw by DBX

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