The problem that we keep encountering is that randomly the threads hang or never return.

For a thread to be joinable, it must "return" from it's code block with a return statement, OR reach the end of the code block.

Since you didn't show how you wrote &somefunction, I can only generalize. 

sub somefunction{

# somehow incorporate an alarm or a loop
# to run a "return" or "goto END" 
.......
if ( $shared_flag ==1 ){ return }
#or
if( $shared_flag == 1 ){ goto END }
......
......

END:
}

[download]
or maybe alarm? 
sub somefunction{
  local $SIG{ALRM} = sub { goto END };
  alarm 10; # wait 10 seconds before interrupting 

  while (1){sleep}

END:
}

[download]
You can also try to detach the thread, and have it set a shared variable when it successfully completes. Then loop through the shared flags at the end of your main thread, and kill hanging threads.
I'm not really a human, but I play one on earth. flash japh

In reply to Re: How to terminate threads that hang or never return? by zentara
in thread How to terminate threads that hang or never return? by JFarr

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.