From 6df7b9816541893a905eec56c333b40673522e84 Mon Sep 17 00:00:00 2001
From: Byron Jones <bjones@mozilla.com>
Date: Thu, 7 Feb 2013 15:56:05 +0800
Subject: Bug 832893: change jobqueue.pl to spawn worker processes to deliver
 bugmail to avoid memory leaks

---
 Bugzilla/JobQueue.pm        | 53 +++++++++++++++++++++++++++++++++++++++++++++
 Bugzilla/JobQueue/Runner.pm | 25 +++++++++++++--------
 jobqueue.pl                 |  1 +
 3 files changed, 70 insertions(+), 9 deletions(-)

diff --git a/Bugzilla/JobQueue.pm b/Bugzilla/JobQueue.pm
index e719efa04..ac97e58c4 100644
--- a/Bugzilla/JobQueue.pm
+++ b/Bugzilla/JobQueue.pm
@@ -27,7 +27,9 @@ use strict;
 use Bugzilla::Constants;
 use Bugzilla::Error;
 use Bugzilla::Install::Util qw(install_string);
+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.
@@ -99,6 +101,57 @@ 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) = @_;
+    $pidfile =~ s/^(.+)(\..+)$/$1.worker$2/;
+    $self->{_worker_pidfile} = $pidfile;
+}
+
 # Clear the request cache at the start of each run.
 sub work_once {
     my $self = shift;
diff --git a/Bugzilla/JobQueue/Runner.pm b/Bugzilla/JobQueue/Runner.pm
index 26755e78f..d45c36647 100644
--- a/Bugzilla/JobQueue/Runner.pm
+++ b/Bugzilla/JobQueue/Runner.pm
@@ -51,6 +51,7 @@ 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} 
@@ -196,21 +197,26 @@ 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");
+    $SIG{__DIE__} = \&Carp::confess if $self->{debug};
+    $self->_do_work($self->{_run_command});
 }
 
 sub _do_work {
@@ -218,6 +224,7 @@ 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);
diff --git a/jobqueue.pl b/jobqueue.pl
index 775fe8dd6..38ea97eb2 100755
--- a/jobqueue.pl
+++ b/jobqueue.pl
@@ -60,6 +60,7 @@ 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
-- 
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