From 011187104f04ef6be208b48dbe3f8e0faeec7e7b Mon Sep 17 00:00:00 2001
From: M Kassaei <m.kassaei@open.ac.uk>
Date: Tue, 27 Mar 2012 14:23:05 +0100
Subject: [PATCH] MDL-32214 quiz regrading: with many attempts, PHP runs out of
 memory

---
 mod/quiz/report/overview/report.php | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/mod/quiz/report/overview/report.php b/mod/quiz/report/overview/report.php
index c7e268149d4..0b82f201bb0 100644
--- a/mod/quiz/report/overview/report.php
+++ b/mod/quiz/report/overview/report.php
@@ -374,6 +374,7 @@ class quiz_overview_report extends quiz_attempt_report {
      */
     protected function regrade_attempt($attempt, $dryrun = false, $slots = null) {
         global $DB;
+        set_time_limit(30);
 
         $transaction = $DB->start_delegated_transaction();
 
@@ -406,6 +407,11 @@ class quiz_overview_report extends quiz_attempt_report {
         }
 
         $transaction->allow_commit();
+
+        // Really, PHP should not need this hint, but without this, we just run out of memory.
+        $quba = null;
+        $transaction = null;
+        gc_collect_cycles();
     }
 
     /**
@@ -445,7 +451,6 @@ class quiz_overview_report extends quiz_attempt_report {
         $this->clear_regrade_table($quiz, $groupstudents);
 
         foreach ($attempts as $attempt) {
-            set_time_limit(30);
             $this->regrade_attempt($attempt, $dryrun);
         }
 
@@ -494,7 +499,6 @@ class quiz_overview_report extends quiz_attempt_report {
         $this->clear_regrade_table($quiz, $groupstudents);
 
         foreach ($attempts as $attempt) {
-            set_time_limit(30);
             $this->regrade_attempt($attempt, false, $attemptquestions[$attempt->uniqueid]);
         }
 
-- 
2.17.1