Add heartbeat logic to compiler server to detect when vm is booted (prevents unnecessary vm restarts)

PBot/VERSION.pm

@@ -13,8 +13,8 @@ use warnings;
 # These are set automatically by the build/commit script
 use constant {
   BUILD_NAME     => "PBot",
-  BUILD_REVISION => 482,
+  BUILD_REVISION => 483,
-  BUILD_DATE     => "2014-02-21",
+  BUILD_DATE     => "2014-02-22",
 };
 
 1;

modules/compiler_vm/compiler_server.pl

@@ -5,8 +5,12 @@ use strict;
 
 use IO::Socket;
 use Net::hostent;
+use IPC::Shareable;
 
-my $PORT = 9000;
+my $SERVER_PORT    = 9000;
+my $MONITOR_PORT   = 3335;
+my $SERIAL_PORT    = 3333;
+my $HEARTBEAT_PORT = 3336;
 
 sub server_listen {
   my $port = shift @_;
@@ -17,7 +21,7 @@ sub server_listen {
     Listen    => SOMAXCONN,
     Reuse     => 1);
 
-  die "can't setup server" unless $server;
+  die "can't setup server: $!" unless $server;
 
   print "[Server $0 accepting clients]\n";
 
@@ -39,7 +43,7 @@ sub vm_start {
   }
 
   if($pid == 0) {
-    my $command = 'nice -n -20 qemu-system-x86_64 -M pc -net none -hda /home/compiler/compiler/compiler-savedvm.qcow2 -m 128 -monitor tcp:127.0.0.1:3335,server,nowait -serial tcp:127.0.0.1:3333,server,nowait -boot c -loadvm 1 -enable-kvm -nographic -no-kvm-irqchip';
+    my $command = "nice -n -20 qemu-system-x86_64 -M pc -net none -hda /home/compiler/compiler/compiler-savedvm.qcow2 -m 128 -monitor tcp:127.0.0.1:$MONITOR_PORT,server,nowait -serial tcp:127.0.0.1:$SERIAL_PORT,server,nowait -serial tcp:127.0.0.1:$HEARTBEAT_PORT,server -boot c -loadvm 1 -enable-kvm -no-kvm-irqchip -nographic";
     my @command_list = split / /, $command;
     exec(@command_list); 
   } else {
@@ -51,7 +55,7 @@ sub vm_reset {
   use IO::Socket;
 
   print "Resetting vm\n";
-  my $sock = IO::Socket::INET->new(PeerAddr => '127.0.0.1', PeerPort => 4445, Prot => 'tcp');
+  my $sock = IO::Socket::INET->new(PeerAddr => '127.0.0.1', PeerPort => $MONITOR_PORT, Prot => 'tcp');
   if(not defined $sock) {
     print "[vm_reset] Unable to connect to monitor: $!\n";
     return;
@@ -59,7 +63,7 @@ sub vm_reset {
 
   print $sock "loadvm 1\n";
   close $sock;
-  print "Resetted vm\n";
+  print "Reset vm\n";
 }
 
 sub execute {
@@ -107,16 +111,64 @@ sub execute {
 }
 
 sub compiler_server {
+  my ($server, $heartbeat_pid, $heartbeat_monitor);
+
+  my $heartbeat;
+  my $running;
+
+  tie $heartbeat, 'IPC::Shareable', 'dat1', { create => 1 };
+  tie $running,   'IPC::Shareable', 'dat2', { create => 1 };
+
+  while(1) {
+    $running = 1;
+    $heartbeat = 0;
+
     my $vm_pid = vm_start;
     print "vm started pid: $vm_pid\n";
 
-  my $server = server_listen($PORT);
+    $heartbeat_pid = fork;
+    die "Fork failed: $!" if not defined $heartbeat_pid;
 
-  while (my $client = $server->accept()) {
+    if($heartbeat_pid == 0) {
+      tie $heartbeat, 'IPC::Shareable', 'dat1', { create => 1 };
+      tie $running,   'IPC::Shareable', 'dat2', { create => 1 };
+
+      $heartbeat_monitor = undef;
+      while(not $heartbeat_monitor) {
+        print "Connecting to heartbeat ...";
+        $heartbeat_monitor = IO::Socket::INET->new(PeerAddr => '127.0.0.1', PeerPort => $HEARTBEAT_PORT, Proto => 'tcp', Type => SOCK_STREAM);
+        if(not $heartbeat_monitor) {
+          print " failed.\n";
+          sleep 2;
+        } else {
+          print " success!\n";
+        }
+      }
+
+      #print "child: running: $running\n";
+
+      while($running and <$heartbeat_monitor>) {
+        $heartbeat = 1;
+        #print "child: got heartbeat\n";
+      }
+
+      #print "child no longer running\n";
+      exit;
+    } else {
+      if(not defined $server) {
+        print "Starting compiler server on port $SERVER_PORT\n";
+        $server = server_listen($SERVER_PORT);
+      } else {
+        print "Compiler server already listening on port $SERVER_PORT\n";
+      }
+
+      #print "parent: running: $running\n";
+
+      while ($running and my $client = $server->accept()) {
         $client->autoflush(1);
         my $hostinfo = gethostbyaddr($client->peeraddr);
         print '-' x 20, "\n";
-    printf "[Connect from %s]\n", $client->peerhost;
+        printf "[Connect from %s at %s]\n", $client->peerhost, scalar localtime;
         my $timed_out = 0;
         my $killed = 0;
 
@@ -135,8 +187,14 @@ sub compiler_server {
             print "got: [$line]\n";
 
             if($line =~ m/^compile:end$/) {
+              if($heartbeat == 0) {
+                print "No heartbeat yet, ignoring compile attempt.\n";
+                print $client "$nick: Recovering from previous snippet, please wait.\n";
+                last;
+              }
+
               $code = quotemeta($code);
-          print "Attemping compile...\n";
+              print "Attempting compile...\n";
               alarm 0;
               my $tnick = quotemeta($nick);
               my $tlang = quotemeta($lang);
@@ -155,7 +213,7 @@ sub compiler_server {
               print "Ret: $ret; result: [$result]\n";
 
               if($result =~ m/\[Killed\]$/) {
-            print "Processed was killed\n";
+                print "Process was killed\n";
                 $killed = 1;
               }
 
@@ -194,8 +252,12 @@ sub compiler_server {
 
         print "stopping vm $vm_pid\n";
         vm_stop $vm_pid;
-    $vm_pid = vm_start;
+        $running = 0;
-    print "new vm pid: $vm_pid\n";
+        last;
+      } 
+      #print "Compiler server no longer running, restarting...\n";
+    }
+    waitpid($heartbeat_pid, 0);
   }
 }
 

modules/compiler_vm/compiler_vm_server.pl

@@ -29,11 +29,12 @@ my %languages = (
 );
 
 sub runserver {
-  my ($input, $output);
+  my ($input, $output, $heartbeat);
 
   if(not defined $USE_LOCAL or $USE_LOCAL == 0) {
     open($input, '<', "/dev/ttyS0") or die $!;
     open($output, '>', "/dev/ttyS0") or die $!;
+    open($heartbeat, '>', "/dev/ttyS1") or die $!;
   } else {
     open($input, '<', "/dev/stdin") or die $!;
     open($output, '>', "/dev/stdout") or die $!;
@@ -47,6 +48,10 @@ sub runserver {
 
   print "Waiting for input...\n";
 
+  my $pid = fork;
+  die "Fork failed: $!" if not defined $pid;
+
+  if($pid == 0) {
     while(my $line = <$input>) {
       chomp $line;
 
@@ -63,7 +68,7 @@ sub runserver {
         print $output "result:$result\n";
         print $output "result:end\n";
 
-      system("rm prog");
+        #system("rm prog");
 
         if(not defined $USE_LOCAL or $USE_LOCAL == 0) {
           print "input: ";
@@ -92,9 +97,16 @@ sub runserver {
 
       $code .= $line . "\n";
     }
+  } else {
+    while(1) {
+      print $heartbeat "\n";
+      sleep 1;
+    }
+  }
 
   close $input;
   close $output;
+  close $heartbeat;
 }
 
 sub interpret {
@@ -108,6 +120,8 @@ sub interpret {
     return "No support for language '$lang' at this time.\n";
   }
 
+  system("chmod -R 755 /home/compiler");
+
   open(my $fh, '>', $languages{$lang}{'file'}) or die $!;
   print $fh $code . "\n";
   close $fh;
@@ -149,6 +163,7 @@ sub interpret {
     $output = "[$result]\n";
   }
 
+  print "Executing gdb\n";
   my $user_input_quoted = quotemeta $user_input;
   ($ret, $result) = execute(60, "bash -c 'date -s \@$date; ulimit -t 1; compiler_watchdog.pl $user_input_quoted > .output'");