Thanks for you quick suggestion, and excuse me for my confusing comment. Actually it is the first time I asking for help on the website, I do miss a lot of things. I am learning HTTP server in Perl, following the instruction of the book <Network Programming with Perl, By Lincoln D. Stein, December 15, 2000>, and doing a lot of test, it is my first attempt to implement a server with adaptive pre-threading technology.

I am working on Microsoft Windows 2000 with Activestate perl v5.8.6 built for MSWin32-x86-multi-thread, and send HTTP request on Firefox web browser with the standard 'GET' method.

  1. lock %{ $cnf{'lock'} } it is a typo, should be lock %{ $stat{'lock'} }
  2. about the nested subroutines: I understand that the subroutines live in the package's symbol table, so it is global not private in the surrounding block, I am doing this just for convenience, they need not be invoked out side of the block. Am I missing something?
  3. thank you for pointing our my misunderstand of the END{} block.
  4. about the signal handler: I intent to stop the server smoothly when press Ctrl+C, if it behaves as what I think, it should increase the $stat{'done'} and then the main loop should break, and END{} is called, exit. But actually it does not, the server does not response to the key sequence, neither when I do like this $SIG{'INT'} = $SIG{'TERM'} = sub { die };
  5. the biggest problem is in the code: 
    LOOP:    while ( !$stat{'work'}{$t}{'stat'} ne 'done' ) {
            {
                lock %{ $stat{'lock'} };
                $c = $listener->accept() or next LOOP;
            }
            
            notify( 'work', $t, 'busy' );
            trc 'log', "new connect accept", $c->peerhost().":".$c->pe
+erport();

            # fix me, the thread blocks here, why?
            # if I lock %{ $cnf{'lock'} } untill close the $c, things 
+will be OK,
            # but then we can't gain advantage of the multi-threads no
+r the pre-threads
            # design.
            if ( my $r = $c->get_request() ) {

    [download]
    when running, one thread get the 'lock' and accept a new connection, then 'unlock', and it is blocked at the last line. I had done following test,
    1. remove the block surrounding the lock action, like this 
      #            {
                lock %{ $stat{'lock'} };
                $c = $listener->accept() or next LOOP;
#            }

      [download]
      it is OK, except the other threads can't accept new connection during the current thread handling the request, because the 'lock' is not released until the handling is finished, the multi-thread server becomes a serial one.
    2. when I remove the get_request() block, send data once the new connection is accepted regardless of the request, it is OK now.

      3. It is really confusing to me.

  6. How does the thread context switch, one more question in 
        sub do_worker {
        my $t = threads->self()->tid();
        
        # wait for the main thread finish initialization
        # fix me, yield can't achieve our purpose, why?
        # threads->yield();
        sleep(1);

    [download]
    if I do not add the last line of code, the main thread do not spawn enough 'worker' threads at the first time, only 2 ones created, but it should be 8 at this time. I guess the current thread is switched to the main thread at that time so I add threads->yield(), then one more 'worker' threads is spawned at the first time, but it is still not what I want. At last I add sleep(1), it is OK then, why?
Looking forward to you kindly help.

In reply to Re^2: multi thread problem in an simple HTTP server by bravesoul
in thread multi thread problem in an simple HTTP server by bravesoul

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.