in reply to join() or detach() which is more memory efficient ?

when I use detach() - I get a DBI error, so when I used join() I dont get the same.

In theory, they should ultimately be much of a muchness once the join has been called. The nice thing about detach is that the cleanup occurs immediately the thread ends rather than waiting until you get around to calling join. Which might save some memory overall if you are starting new threads on the fly as their stack segments can be reused (earlier).

when I use detach() - I get a DBI error, so when I used join() I dont get the same.

That suggests that you, or the modules you are using, have some kind of error, and warrants further investigation.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
  • Comment on Re: join() or detach() which is more memory efficient ?

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Re^2: join() or detach() which is more memory efficient ?
by goutamram (Initiate) on Mar 25, 2011 at 16:11 UTC
    Thank you! But since both does the same cleanup and join() does it at a later stage - I think both should have the same memory efficiency !?!
[reply]
      But since both does the same cleanup and join() does it at a later stage - I think both should have the same memory efficiency

      If you do:

      my $a = async {
    ...
};
... some other stuff;

my $b = async {
    ...
};
$_->join for $a, $b;

      [download]

      Your peak memory usage may be slightly higher than if you do:

      async {
    ...
}->detach;
... some other stuff;

async {
    ...
}->detach;

      [download]

      Because the second thread will require the process to allocate more virtual memory to accomodate the stack space for the second thread, because the first thread hasn't been joined when it is created.

      Whereas, with the second snippet, the first thread may have completed before the second thread is created, and so the memory used by the first thread can be reused for the second. Thereby the total memory consumption may be a little lower. It's all a matter of timing.

      If total memory consumption isn't a problem, just ignore it.

      I'd still want to investigate the DBI error though. It is likely also a timing problem.

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
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