--- loncom/Attic/lonc 2002/03/03 18:13:07 1.31
+++ loncom/Attic/lonc 2002/03/20 03:42:45 1.33
@@ -5,7 +5,7 @@
# provides persistent TCP connections to the other servers in the network
# through multiplexed domain sockets
#
-# $Id: lonc,v 1.31 2002/03/03 18:13:07 harris41 Exp $
+# $Id: lonc,v 1.33 2002/03/20 03:42:45 foxr Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -45,7 +45,7 @@
# 12/20 Scott Harrison
# YEAR=2002
# 2/19/02,02/22/02,02/25/02 Gerd Kortemeyer
-#
+# 3/07/02 Ron Fox
# based on nonforker from Perl Cookbook
# - server who multiplexes without forking
@@ -57,12 +57,13 @@ use Socket;
use Fcntl;
use Tie::RefHash;
use Crypt::IDEA;
-use Net::Ping;
+#use Net::Ping;
use LWP::UserAgent();
$status='';
$lastlog='';
$conserver='SHELL';
+$DEBUG = 0; # Set to 1 for annoyingly complete logs.
# -------------------------------- Set signal handlers to record abnormal exits
@@ -158,47 +159,53 @@ $SIG{HUP}=$SIG{USR1}='IGNORE';
&status("Forking ...");
foreach $thisserver (keys %hostip) {
- if (&online($hostname{$thisserver})) {
+ #if (&online($hostname{$thisserver})) {
make_new_child($thisserver);
- }
+ #}
}
&logthis("Done starting initial servers");
# ----------------------------------------------------- Install signal handlers
-$SIG{CHLD} = \&REAPER;
+
$SIG{INT} = $SIG{TERM} = \&HUNTSMAN;
$SIG{HUP} = \&HUPSMAN;
$SIG{USR1} = \&USRMAN;
# And maintain the population.
while (1) {
- &status("Sleeping");
- sleep; # wait for a signal (i.e., child's death)
+ my $deadpid = wait; # Wait for the next child to die.
# See who died and start new one
&status("Woke up");
my $skipping='';
- foreach $thisserver (keys %hostip) {
- if (!$childpid{$thisserver}) {
- if (($childatt{$thisserver}<$childmaxattempts) &&
- (&online($hostname{$thisserver}))) {
- $childatt{$thisserver}++;
- &logthis(
- "INFO: Trying to reconnect for $thisserver "
- ."($childatt{$thisserver} of $childmaxattempts attempts)");
- make_new_child($thisserver);
- } else {
- $skipping.=$thisserver.' ';
- }
-
- }
- }
- if ($skipping) {
- &logthis("WARNING: Skipped $skipping");
+
+ if(exists($children{$deadpid})) {
+
+ $thisserver = $children{$deadpid}; # Look name of dead guy's peer.
+
+ delete($children{$deadpid}); # Get rid of dead hash entry.
+
+ if($childatt{$thisserver} < $childmaxattempts) {
+ $childatt{$thisserver}++;
+ &logthis(
+ "INFO: Trying to reconnect for $thisserver "
+ ."($childatt{$thisserver} of $childmaxattempts attempts)");
+ make_new_child($thisserver);
+
+ }
+ else {
+ $skipping .= $thisserver.' ';
+ }
+ if($skipping) {
+ &logthis("WARNING: Skipped $skipping");
+
+ }
}
+
}
+
sub make_new_child {
$newserver=shift;
@@ -217,7 +224,7 @@ sub make_new_child {
sigprocmask(SIG_UNBLOCK, $sigset)
or die "Can't unblock SIGINT for fork: $!\n";
$children{$pid} = $newserver;
- $childpid{$conserver} = $pid;
+ $childpid{$newserver} = $pid;
return;
} else {
$conserver=$newserver;
@@ -238,9 +245,10 @@ unlink($port);
# -------------------------------------------------------------- Open other end
&openremote($conserver);
-
+ &logthis(" Connection to $conserver open ");
# ----------------------------------------- We're online, send delayed messages
&status("Checking for delayed messages");
+
my @allbuffered;
my $path="$perlvar{'lonSockDir'}/delayed";
opendir(DIRHANDLE,$path);
@@ -250,7 +258,7 @@ unlink($port);
foreach (@allbuffered) {
&status("Sending delayed: $_");
$dfname="$path/$_";
- &logthis('Sending '.$dfname);
+ if($DEBUG) { &logthis('Sending '.$dfname); }
my $wcmd;
{
my $dfh=IO::File->new($dfname);
@@ -271,17 +279,8 @@ unlink($port);
}
$cmd="enc:$cmdlength:$encrequest\n";
}
- $SIG{ALRM}=sub { die "timeout" };
- $SIG{__DIE__}='DEFAULT';
- eval {
- alarm(60);
- print $remotesock "$cmd\n";
- $answer=<$remotesock>;
+ $answer = londtransaction($remotesock, $cmd, 60);
chomp($answer);
- alarm(0);
- };
- $SIG{ALRM}='DEFAULT';
- $SIG{__DIE__}=\&catchexception;
if (($answer ne '') && ($@!~/timeout/)) {
unlink("$dfname");
@@ -289,6 +288,7 @@ unlink($port);
&logperm("S:$conserver:$bcmd");
}
}
+ if($DEBUG) { &logthis(" Delayed transactions sent"); }
# ------------------------------------------------------- Listen to UNIX socket
&status("Opening socket");
@@ -300,11 +300,11 @@ unless (
my $st=120+int(rand(240));
&logthis(
"WARNING: ".
- "Can't make server socket ($st secs): $@");
+ "Can't make server socket ($st secs): .. exiting");
sleep($st);
exit;
};
-
+
# -----------------------------------------------------------------------------
&logthis("$conserver online");
@@ -329,8 +329,8 @@ while (1) {
# check for new information on the connections we have
# anything to read or accept?
- foreach $client ($select->can_read(0.1)) {
+ foreach $client ($select->can_read(100.0)) {
if ($client == $server) {
# accept a new connection
&status("Accept new connection: $conserver");
@@ -356,6 +356,7 @@ while (1) {
$inbuffer{$client} .= $data;
+
# test whether the data in the buffer or the data we
# just read means there is a complete request waiting
# to be fulfilled. If there is, set $ready{$client}
@@ -365,12 +366,12 @@ while (1) {
}
}
}
-
+
# Any complete requests to process?
foreach $client (keys %ready) {
handle($client);
}
-
+
# Buffers to flush?
foreach $client ($select->can_write(1)) {
# Skip this client if we have nothing to say
@@ -426,16 +427,19 @@ sub handle {
# send output to $outbuffer{$client}
my $client = shift;
my $request;
-
foreach $request (@{$ready{$client}}) {
# ============================================================= Process request
# $request is the text of the request
# put text of reply into $outbuffer{$client}
# ------------------------------------------------------------ Is this the end?
+ chomp($request);
+ if($DEBUG) {
+ &logthis(" Request $request processing starts");
+ }
if ($request eq "close_connection_exit\n") {
&status("Request close connection");
&logthis(
- "CRITICAL: Request Close Connection");
+ "CRITICAL: Request Close Connection ... exiting");
$remotesock->shutdown(2);
$server->close();
exit;
@@ -452,27 +456,19 @@ sub handle {
$encrequest.=
unpack("H16",$cipher->encrypt(substr($cmd,$encidx,8)));
}
- $request="enc:$cmdlength:$encrequest\n";
+ $request="enc:$cmdlength:$encrequest";
}
# --------------------------------------------------------------- Main exchange
- $SIG{ALRM}=sub { die "timeout" };
- $SIG{__DIE__}='DEFAULT';
- eval {
- alarm(300);
- &status("Sending: $request");
- print $remotesock "$request";
- &status("Waiting for reply from $conserver: $request");
- $answer=<$remotesock>;
- &status("Received reply: $request");
- alarm(0);
- };
- if ($@=~/timeout/) {
- $answer='';
- &logthis(
- "CRITICAL: Timeout: $request");
- }
- $SIG{ALRM}='DEFAULT';
- $SIG{__DIE__}=\&catchexception;
+ $answer = londtransaction($remotesock, $request, 300);
+
+ if($DEBUG) {
+ &logthis(" Request data exchange complete");
+ }
+ if ($@=~/timeout/) {
+ $answer='';
+ &logthis(
+ "CRITICAL: Timeout: $request");
+ }
if ($answer) {
@@ -488,17 +484,25 @@ sub handle {
$answer=substr($answer,0,$cmdlength);
$answer.="\n";
}
+ if($DEBUG) {
+ &logthis("sending $answer to client\n");
+ }
$outbuffer{$client} .= $answer;
} else {
$outbuffer{$client} .= "con_lost\n";
}
&status("Completed: $request");
-
+ if($DEBUG) {
+ &logthis(" Request processing complete");
+ }
# ===================================================== Done processing request
}
delete $ready{$client};
# -------------------------------------------------------------- End non-forker
+ if($DEBUG) {
+ &logthis(" requests for child handled");
+ }
}
# ---------------------------------------------------------- End make_new_child
}
@@ -522,6 +526,7 @@ sub openremote {
my $conserver=shift;
&status("Opening TCP");
+ my $st=120+int(rand(240)); # Sleep before opening:
unless (
$remotesock = IO::Socket::INET->new(PeerAddr => $hostip{$conserver},
@@ -529,32 +534,24 @@ unless (
Proto => "tcp",
Type => SOCK_STREAM)
) {
- my $st=120+int(rand(240));
+
&logthis(
-"WARNING: Couldn't connect ($st secs): $@");
+"WARNING: Couldn't connect to $conserver ($st secs): ");
sleep($st);
exit;
};
# ----------------------------------------------------------------- Init dialog
+&logthis("INFO Connected to $conserver, initing ");
&status("Init dialogue: $conserver");
- $SIG{ALRM}=sub { die "timeout" };
- $SIG{__DIE__}='DEFAULT';
- eval {
- alarm(60);
-print $remotesock "init\n";
-$answer=<$remotesock>;
-print $remotesock "$answer";
-$answer=<$remotesock>;
-chomp($answer);
- alarm(0);
- };
- $SIG{ALRM}='DEFAULT';
- $SIG{__DIE__}=\&catchexception;
+ $answer = londtransaction($remotesock, "init", 60);
+ chomp($answer);
+ $answer = londtransaction($remotesock, $answer, 60);
+ chomp($answer);
if ($@=~/timeout/) {
- &logthis("Timed out during init");
+ &logthis("Timed out during init.. exiting");
exit;
}
@@ -597,7 +594,7 @@ if ($cipher=new IDEA $cipherkey) {
sleep($st);
exit;
}
-
+ &logthis(" Remote open success ");
}
@@ -610,21 +607,21 @@ sub catchexception {
chomp($signal);
&logthis("CRITICAL: "
."ABNORMAL EXIT. Child $$ for server [$wasserver] died through "
- ."\"$signal\" with parameter [$@]");
- die($@);
+ ."\"$signal\" with parameter ");
+ die("Signal abend");
}
# -------------------------------------- Routines to see if other box available
-sub online {
- my $host=shift;
- &status("Pinging ".$host);
- my $p=Net::Ping->new("tcp",20);
- my $online=$p->ping("$host");
- $p->close();
- undef ($p);
- return $online;
-}
+#sub online {
+# my $host=shift;
+# &status("Pinging ".$host);
+# my $p=Net::Ping->new("tcp",20);
+# my $online=$p->ping("$host");
+# $p->close();
+# undef ($p);
+# return $online;
+#}
sub connected {
my ($local,$remote)=@_;
@@ -635,7 +632,7 @@ sub connected {
unless ($hostname{$local}) { return 'local_unknown'; }
unless ($hostname{$remote}) { return 'remote_unknown'; }
- unless (&online($hostname{$local})) { return 'local_offline'; }
+ #unless (&online($hostname{$local})) { return 'local_offline'; }
my $ua=new LWP::UserAgent;
@@ -654,17 +651,6 @@ sub connected {
}
-sub REAPER { # takes care of dead children
- $SIG{CHLD} = \&REAPER;
- my $pid = wait;
- my $wasserver=$children{$pid};
- &logthis("CRITICAL: "
- ."Child $pid for server $wasserver died ($childatt{$wasserver})");
- delete $children{$pid};
- delete $childpid{$wasserver};
- my $port = "$perlvar{'lonSockDir'}/$wasserver";
- unlink($port);
-}
sub hangup {
foreach (keys %children) {
@@ -725,15 +711,8 @@ sub subreply {
or return "con_lost";
- $SIG{ALRM}=sub { die "timeout" };
- $SIG{__DIE__}='DEFAULT';
- eval {
- alarm(10);
- print $sclient "$cmd\n";
- $answer=<$sclient>;
- chomp($answer);
- alarm(0);
- };
+ $answer = londtransaction($sclient, $cmd, 10);
+
if ((!$answer) || ($@=~/timeout/)) { $answer="con_lost"; }
$SIG{ALRM}='DEFAULT';
$SIG{__DIE__}=\&catchexception;
@@ -753,6 +732,83 @@ sub logthis {
print $fh "$local ($$) [$conserver] [$status]: $message\n";
}
+#-------------------------------------- londtransaction:
+#
+# Performs a transaction with lond with timeout support.
+# result = londtransaction(socket,request,timeout)
+#
+sub londtransaction {
+ my ($socket, $request, $tmo) = @_;
+
+ if($DEBUG) {
+ &logthis("londtransaction request: $request");
+ }
+
+ # Set the signal handlers: ALRM for timeout and disble the others.
+
+ $SIG{ALRM} = sub { die "timeout" };
+ $SIG{__DIE__} = 'DEFAULT';
+
+ # Disable all but alarm so that only that can interupt the
+ # send /receive.
+ #
+ my $sigset = POSIX::SigSet->new(QUIT, USR1, HUP, INT, TERM);
+ my $priorsigs = POSIX::SigSet->new;
+ unless (defined sigprocmask(SIG_BLOCK, $sigset, $priorsigs)) {
+ &logthis(" CRITICAL -- londtransaction ".
+ "failed to block signals ");
+ die "could not block signals in londtransaction";
+ }
+ $answer = '';
+ #
+ # Send request to lond.
+ #
+ eval {
+ alarm($tmo);
+ print $socket "$request\n";
+ alarm(0);
+ };
+ # If request didn't timeout, try for the response.
+ #
+
+ if ($@!~/timeout/) {
+ eval {
+ alarm($tmo);
+ $answer = <$socket>;
+ if($DEBUG) {
+ &logthis("Received $answer in londtransaction");
+ }
+ alarm(0);
+ };
+ } else {
+ if($DEBUG) {
+ &logthis("Timeout on send in londtransaction");
+ }
+ }
+ if( ($@ =~ /timeout/) && ($DEBUG)) {
+ &logthis("Timeout on receive in londtransaction");
+ }
+ #
+ # Restore the initial sigmask set.
+ #
+ unless (defined sigprocmask(SIG_UNBLOCK, $priorsigs)) {
+ &logthis(" CRITICAL -- londtransaction ".
+ "failed to re-enable signal processing. ");
+ die "londtransaction failed to re-enable signals";
+ }
+ #
+ # go back to the prior handler set.
+ #
+ $SIG{ALRM} = 'DEFAULT';
+ $SIG{__DIE__} = \&cathcexception;
+
+ # chomp $answer;
+ if ($DEBUG) {
+ &logthis("Returning $answer in londtransaction");
+ }
+ return $answer;
+
+}
sub logperm {
my $message=shift;
@@ -813,6 +869,11 @@ B forks off children processes tha
in the network. Management of these processes can be done at the
parent process level or the child process level.
+ After forking off the children, B the B
+executes a main loop which simply waits for processes to exit.
+As a process exits, a new process managing a link to the same
+peer as the exiting process is created.
+
B is the location of log messages.
The process management is now explained in terms of linux shell commands,
@@ -888,23 +949,6 @@ Subroutine B:
SIGUSR1 is sent to all the children, and the status of
each connection is logged.
-=item *
-
-SIGCHLD
-
-Parent signal assignment:
- $SIG{CHLD} = \&REAPER;
-
-Child signal assignment:
- none
-
-Command-line invocations:
- B B<-s> SIGCHLD I
-
-Subroutine B:
- This is only invoked for the B parent I.
-Information pertaining to the child is removed.
-The socket port is cleaned up.
=back