in reply to Re: threads with shared variables across multiple instances of a module
in thread threads with shared variables across multiple instances of a module

Ah yes perfect, thanks! I thought about this, but figured the same problem would occur with the same variable name, but I guess inside of the function its able to have a unique reference to it, great!

Beats my other hack around using self and sharing parts of the hash - which apparently is possible :D

Thanks again.

  • Comment on Re^2: threads with shared variables across multiple instances of a module

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Re^3: threads with shared variables across multiple instances of a module
by BrowserUk (Patriarch) on Mar 25, 2010 at 19:56 UTC

    Yes, you can share individual elements of a hash (using share()):

    use strict; use warnings; use threads; use threads::shared; my %h; share $h{ fred }; $h{fred} = 2; async{ my $a='bill'; lock $h{fred}; $h{fred}=$a; }->join; print $h{fred}; bill

    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.

      can i share the whole hash ?? a can't push in my shared hash pair like this:

      "192.168.0.1:3128" => $client

      $client is a local (defined with "my") variable (socket)

      part of my code:

      ..... use strict; use Socket; use threads; use threads::shared; ....... my %clients :shared; ...... my $server = IO::Socket::INET -> new(.....); ..... while( my $client = $server -> accept ) { ..... ############### in next 2 strings i'm wall!!! i don't know how push $socket (it's refe +rence to NANDLE, isn't it?!) in shared hash %clients, and then get it + back like a handle!! the best error i've had, was "Bad file descriptor" ################ $clients{ "$client_ip:$client_port" } = *client{IO}; # add new socket +to %client syswrite( $$qwe{IO}, "hi, how are you??") || die ":$! _ $@"; ..... }

      help me please, desparing

        This  *client{IO}; is invalid syntax when $client is a lexical.

        It would have to be *{ $client }{IO}.

        But that still won't help you because of an (unnecessary) restriction that doesn't allow you to store globs, (or references to globs) into shared scalars.

        There are two ways to share globs (filehandles sockets etc.) between threads:

        1. Share the file number between threads and dup() the associated filehandle into existance in teh target thread(s):
          my %clients :shared; while( my $client = $server->accept; $clients{ client } = fileno( $client ); } ... ## within the threads my $client; my $fileno = $clients{ client }; open $client, "+<&$fileno" or die ... ## dup() the the glob from the f +ileno ## use $client
        2. Allow the thread access to the client handle via cloned closure:
          while( my $client = $server->accept ) { async{ while( my $in = <$client> ) { print $client $in; ### simple echo server } }->detach; }

        I've never understood this restriction. The fact that a glob can be successfully shared via the latter method suggests strongly that the restriction both artifical (they just decided to reject glob(ref) assignments to shared scalars--and the code supports this); and unnecessary.

        But those that should know the answer to why this restriction was established and persists, have chosen not to answer that question.


        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.

      perhaps i didn't understand, but i have the same error "Thread 1 terminated abnormally: : Bad file descriptor". can explain to me ?

      6 use strict; 7 use IO::Socket; 9 use threads; 10 use threads::shared; 12 use constant BUFSIZE => 1024; ......... # create port, also "new" try bind, listen 31 my $server = IO::Socket::INET -> new( ............. 41 threads -> create( \&to_client ) || die "$! \n"; # STDIN, send + writed to client you point, like this "192.168.0.1:3128 my message", + also have "list" command # start threads to treat querys 44 while( my $client = $server -> accept ) { 45 my $client_ip = $client -> peerhost(); 46 my $client_port = $client -> peerport(); 47 my $tmp = "$client_ip:$client_port"; 48 ## ????? IN THIS PLACE I WANT TO PUSH SOCKET $client a +s value in hash %clients with key "$client_ip:$client_port" ???? 49 %clients = ( %clients, "$client_ip:$client_port" => fi +leno($client) ) ; # add new socket to %clients 50 54 print "got a connection from: $client_ip:$client_port +$client\n"; 55 $client -> autoflush; # don't buffer 56 57 threads -> create( \&from_client, $client, $client_ip, + $client_port ) || die "$! \n"; #STDOUT, get message from client 58 59 } 60 exit 0; # ****************************************************** 79 # send message to client, or get list of clients 80 sub to_client { 81 my ( $clnt_ip_port, $msg_t, $tmp ); 82 83 while( sysread(STDIN, $tmp, BUFSIZE) ) { 84 #print "debug1 $tmp"; 85 chomp $tmp; # very-very need, difficult to exp +lain =) 86 if( $tmp eq "list" ) { # show list of clients 87 print "connect to this server:\n"; 88 foreach my $z ( keys %clients ) { prin +t "client: $z $clients{$z}\n"; } 89 } 90 elsif ( $tmp =~ /\d{1,3}\.\d{1,3}\.\d{1,3}\.\d +{1,3}:\d{4,5}\s.*/ ) { # find in STDIN blank 91 ( $clnt_ip_port, $msg_t ) = ( $tmp =~ +/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}:\d{4,5})\s(.*)/ ); # split messa +ge to addres like "192.168.0.1:3128" (it is key fo r %clients) + and message 92 #print "debug1 blank {$clnt_ip_port} {$msg_t}\n"; 93 if ( exists $clients{$clnt_ip_port} ) +{ # if key exist in %clients then send 94 #print "syswrite $clients{$clnt_ip_port} {$msg_t} \n"; ????? IN THIS PLACE I WANT TO GET IT BACK ( SOCKET $client as +value from hash %clients with key "$client_ip:$client_port" ) ???? 95 my $client; 96 my $fileno = $clients{$clnt_ip +_port}; 97 open $client, "+<$fileno" || d +ie "open: $!\n"; 98 syswrite( $client, $msg_t ) || + die ": $! __ $@\n"; 99 close $client; 100 } else { print "don't exist client or +empty message!\n"; } 101 } else { print "wrong value, check and see \"l +ist\" of clients!\n"; } 102 } 103 } 106 # ****************************************************** 107 # STDOUT, get message from client 108 sub from_client { 109 my ( $sock, $clnt_ip, $clnt_port ) = @_;; 110 my $msg_f; 111 112 syswrite( STDOUT, "from $clnt_ip:$clnt_port: $msg_f" ) + while sysread( $sock, $msg_f, BUFSIZE ); 113 print "client at $clnt_ip:$clnt_port closed connection + \n"; 114 delete $clients{"$clnt_ip:$clnt_port"}; # delete socke +t from %client 115 116 $sock -> close; 117 }

        If you included the full error message (including the line number), I'd have a chance of knowing which thread terminated abnormally.

        If you included all the source code, I might stand a chance of trying it out for myself.

        If you posted the code without the line numbers, I wouldn't have to strip them off.

        And your code would be far easier (for you and me) to read and analyse if it was formatted consistently.

        As it is, the most obvious problem is that %clients isn't declared (or shared) anywhere.

        And BTW, this %clients = ( %clients, "$client_ip:$client_port" => fileno($client) ) ; is a really horrible way to add a new key/value pair to a hash. A simple:

        $clients{ "$client_ip:$client_port" } = fileno($client);

        is much easier to read and far more efficient.

        You've also failed to do any locking of your shared hash. (Assuming it is actually declared & shared somewhere in the code you've omitted!)


        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.