From cd1d5eb785a759d285652551f1984ce9877a1192 Mon Sep 17 00:00:00 2001
From: Alan Protasio <alanprot@gmail.com>
Date: Wed, 6 Mar 2019 15:33:52 -0800
Subject: [PATCH] AMQ-7163 - If the broker had an unclean shutdown and number
 of free pages is Zero after the recovery, the next shutdown will also be
 'unclean'

---
 .../store/kahadb/disk/page/PageFile.java      |  7 +++
 .../store/kahadb/disk/page/PageFileTest.java  | 50 +++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/disk/page/PageFile.java b/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/disk/page/PageFile.java
index 15694d4b92..3f6a34d8f9 100644
--- a/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/disk/page/PageFile.java
+++ b/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/disk/page/PageFile.java
@@ -485,6 +485,9 @@ public class PageFile {
 
             // allow flush (with index lock held) to merge eventually
             recoveredFreeList.lazySet(newFreePages);
+        } else {
+            // If there is no free pages, set trackingFreeDuringRecovery to allow the broker to have a clean shutdown
+            trackingFreeDuringRecovery.set(null);
         }
     }
 
@@ -558,6 +561,10 @@ public class PageFile {
         return loaded.get();
     }
 
+    public boolean isCleanShutdown() {
+        return metaData != null && metaData.isCleanShutdown();
+    }
+
     public void allowIOResumption() {
         loaded.set(true);
     }
diff --git a/activemq-kahadb-store/src/test/java/org/apache/activemq/store/kahadb/disk/page/PageFileTest.java b/activemq-kahadb-store/src/test/java/org/apache/activemq/store/kahadb/disk/page/PageFileTest.java
index e2e4ec528b..11b28a8ed2 100644
--- a/activemq-kahadb-store/src/test/java/org/apache/activemq/store/kahadb/disk/page/PageFileTest.java
+++ b/activemq-kahadb-store/src/test/java/org/apache/activemq/store/kahadb/disk/page/PageFileTest.java
@@ -361,6 +361,56 @@ public class PageFileTest extends TestCase {
         }, 12000000));
     }
 
+    public void testRecoveryAfterUncleanShutdownAndZeroFreePages() throws Exception {
+        final int numberOfPages = 1000;
+        final AtomicBoolean recoveryEnd = new AtomicBoolean();
+
+        Appender appender = new DefaultTestAppender() {
+            @Override
+            public void doAppend(LoggingEvent event) {
+                if (event.getLevel().equals(Level.INFO) && event.getMessage().toString().contains("Recovered pageFile free list")) {
+                    recoveryEnd.set(true);
+                }
+            }
+        };
+
+        org.apache.log4j.Logger log4jLogger =
+                org.apache.log4j.Logger.getLogger(PageFile.class);
+        log4jLogger.addAppender(appender);
+        log4jLogger.setLevel(Level.DEBUG);
+
+        PageFile pf = new PageFile(new File("target/test-data"), getName());
+        pf.delete();
+        pf.setEnableRecoveryFile(false);
+        pf.load();
+
+        LOG.info("Creating Transactions");
+        for (int i = 0; i < numberOfPages; i++) {
+            Transaction tx = pf.tx();
+            Page page = tx.allocate();
+            String t = "page:" + i;
+            page.set(t);
+            tx.store(page, StringMarshaller.INSTANCE, false);
+            tx.commit();
+        }
+
+        pf.flush();
+
+        assertEquals(pf.getFreePageCount(), 0);
+
+        //Simulate an unclean shutdown
+        PageFile pf2 = new PageFile(new File("target/test-data"), getName());
+        pf2.setEnableRecoveryFile(false);
+        pf2.load();
+
+        assertTrue("Recovery Finished", Wait.waitFor(recoveryEnd::get, 100000));
+
+        //Simulate a clean shutdown
+        pf2.unload();
+        assertTrue(pf2.isCleanShutdown());
+
+    }
+
     public void testBackgroundWillMarkUsedPagesAsFreeInTheBeginning() throws Exception {
         final int numberOfPages = 100000;
         final AtomicBoolean recoveryEnd = new AtomicBoolean();