Bug 832893: changes jobqueue.pl to spawn worker processes to deliver bugmail to avoid memory leaks

r=dkl, a=LpSolit

Bugzilla/JobQueue.pm

@@ -13,7 +13,10 @@ use strict;
 use Bugzilla::Constants;
 use Bugzilla::Error;
 use Bugzilla::Install::Util qw(install_string);
-use parent qw(TheSchwartz);
+use File::Basename;
+use File::Slurp;
+use base qw(TheSchwartz);
+use fields qw(_worker_pidfile);
 
 # This maps job names for Bugzilla::JobQueue to the appropriate modules.
 # If you add new types of jobs, you should add a mapping here.
@@ -93,6 +96,57 @@ sub insert {
     return $retval;
 }
 
+# To avoid memory leaks/fragmentation which tends to happen for long running
+# perl processes; check for jobs, and spawn a new process to empty the queue.
+sub subprocess_worker {
+    my $self = shift;
+
+    my $command = "$0 -d -p '" . $self->{_worker_pidfile} . "' onepass";
+
+    while (1) {
+        my $time = (time);
+        my @jobs = $self->list_jobs({
+            funcname      => $self->{all_abilities},
+            run_after     => $time,
+            grabbed_until => $time,
+            limit         => 1,
+        });
+        if (@jobs) {
+            $self->debug("Spawning queue worker process");
+            # Run the worker as a daemon
+            system $command;
+            # And poll the PID to detect when the working has finished.
+            # We do this instead of system() to allow for the INT signal to
+            # interrup us and trigger kill_worker().
+            my $pid = read_file($self->{_worker_pidfile}, err_mode => 'quiet');
+            if ($pid) {
+                sleep(3) while(kill(0, $pid));
+            }
+            $self->debug("Queue worker process completed");
+        } else {
+            $self->debug("No jobs found");
+        }
+        sleep(5);
+    }
+}
+
+sub kill_worker {
+    my $self = Bugzilla->job_queue();
+    if ($self->{_worker_pidfile} && -e $self->{_worker_pidfile}) {
+        my $worker_pid = read_file($self->{_worker_pidfile});
+        if ($worker_pid && kill(0, $worker_pid)) {
+            $self->debug("Stopping worker process");
+            system "$0 -f -p '" . $self->{_worker_pidfile} . "' stop";
+        }
+    }
+}
+
+sub set_pidfile {
+    my ($self, $pidfile) = @_;
+    $self->{_worker_pidfile} = bz_locations->{'datadir'} .
+                               '/worker-' . basename($pidfile);
+}
+
 # Clear the request cache at the start of each run.
 sub work_once {
     my $self = shift;
@@ -136,4 +190,8 @@ be sent away to be done later.
 
 =item job_map
 
+=item set_pidfile
+
+=item kill_worker
+
 =back

Bugzilla/JobQueue/Runner.pm

@@ -38,6 +38,7 @@ our $initscript = "bugzilla-queue";
 sub gd_preconfig {
     my $self = shift;
 
+    $self->{_run_command} = 'subprocess_worker';
     my $pidfile = $self->{gd_args}{pidfile};
     if (!$pidfile) {
         $pidfile = bz_locations()->{datadir} . '/' . $self->{gd_progname} 
@@ -136,6 +137,7 @@ sub gd_can_install {
             print $config_fh <<END;
 #!/bin/sh
 BUGZILLA="$directory"
+# This user must have write access to Bugzilla's data/ directory.
 USER=$owner
 END
             close($config_fh);
@@ -183,21 +185,25 @@ sub gd_setup_signals {
     $SIG{TERM} = sub { $self->gd_quit_event(); }
 }
 
-sub gd_other_cmd {
-    my ($self) = shift;
-    if ($ARGV[0] eq "once") {
-        $self->_do_work("work_once");
+sub gd_quit_event {
+    Bugzilla->job_queue->kill_worker();
+    exit(1);
+}
 
-        exit(0);
+sub gd_other_cmd {
+    my ($self, $do, $locked) = @_;
+    if ($do eq "once") {
+        $self->{_run_command} = 'work_once';
+    } elsif ($do eq "onepass") {
+        $self->{_run_command} = 'work_until_done';
+    } else {
+        $self->SUPER::gd_other_cmd($do, $locked);
     }
-    
-    $self->SUPER::gd_other_cmd();
 }
 
 sub gd_run {
     my $self = shift;
-
-    $self->_do_work("work");
+    $self->_do_work($self->{_run_command});
 }
 
 sub _do_work {
@@ -205,11 +211,11 @@ sub _do_work {
 
     my $jq = Bugzilla->job_queue();
     $jq->set_verbose($self->{debug});
+    $jq->set_pidfile($self->{gd_pidfile});
     foreach my $module (values %{ Bugzilla::JobQueue->job_map() }) {
         eval "use $module";
         $jq->can_do($module);
     }
-
     $jq->$fn;
 }
 
@@ -242,6 +248,8 @@ to run the Bugzilla job queue.
 
 =item gd_can_install
 
+=item gd_quit_event
+
 =item gd_other_cmd
 
 =item gd_more_opt

jobqueue.pl

@@ -46,6 +46,7 @@ jobqueue.pl - Runs jobs in the background for Bugzilla.
              starts a new one.
    once      Checks the job queue once, executes the first item found (if
              any) and then exits
+   onepass   Checks the job queue, executes all items found, and then exits
    check     Report the current status of the daemon.
    install   On some *nix systems, this automatically installs and
              configures jobqueue.pl as a system service so that it will

t/011pod.t

@@ -30,7 +30,7 @@ use constant DEFAULT_WHITELIST => qr/^(?:new|new_from_list|check|run_create_vali
 use constant SUB_WHITELIST => (
     'Bugzilla::Flag'     => qr/^(?:(force_)?retarget|force_cleanup)$/,
     'Bugzilla::FlagType' => qr/^sqlify_criteria$/,
-    'Bugzilla::JobQueue' => qr/^work_once$/,
+    'Bugzilla::JobQueue' => qr/(?:^work_once|subprocess_worker)$/,
 );
 
 # These modules do not need to be documented, generally because they