-
Notifications
You must be signed in to change notification settings - Fork 2.3k
/
TestLockManagerBean.java
212 lines (183 loc) · 7.5 KB
/
TestLockManagerBean.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
/**
* Copyright (c) 2002-2016 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.management;
import java.lang.Thread.State;
import java.util.Collection;
import java.util.List;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.neo4j.graphdb.Lock;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Transaction;
import org.neo4j.jmx.impl.JmxKernelExtension;
import org.neo4j.kernel.GraphDatabaseAPI;
import org.neo4j.kernel.info.LockInfo;
import org.neo4j.kernel.info.LockingTransaction;
import org.neo4j.kernel.info.ResourceType;
import org.neo4j.test.ImpermanentDatabaseRule;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
public class TestLockManagerBean
{
private LockManager lockManager;
@Rule
public ImpermanentDatabaseRule dbRule = new ImpermanentDatabaseRule();
@SuppressWarnings("deprecation")
private GraphDatabaseAPI graphDb;
@Before
public void setup()
{
graphDb = dbRule.getGraphDatabaseAPI();
lockManager = graphDb.getDependencyResolver().resolveDependency( JmxKernelExtension.class )
.getSingleManagementBean( LockManager.class );
}
@Test
public void restingGraphHoldsNoLocks()
{
assertEquals( "unexpected lock count", 0, lockManager.getLocks().size() );
}
@Test
public void modifiedNodeImpliesLock()
{
Node node = createNode();
try(Transaction ignore = graphDb.beginTx())
{
node.setProperty( "key", "value" );
List<LockInfo> locks = lockManager.getLocks();
assertEquals( "unexpected lock count", 2, locks.size() );
LockInfo lock = locks.get( 0 );
assertNotNull( "null lock", lock );
Collection<LockingTransaction> transactions = lock.getLockingTransactions();
assertEquals( "unexpected transaction count", 1, transactions.size() );
LockingTransaction txInfo = transactions.iterator().next();
assertNotNull( "null transaction", txInfo );
assertEquals( "read count", 0, txInfo.getReadCount() );
/* Before property handling moved from Primitive into the Kernel API there were two
* locks acquired for setting a property. One was about acquiring a write lock for that entity
* before even accessing the Primitive. The other one was the normal write lock for a change
* to an entity. The former guarded for a property data race, which is at the point of writing this
* unknown if it exists after the move or not (which also made the change to only acquire
* one lock again). */
assertEquals( "write count should be 1", 1, txInfo.getWriteCount() );
assertNotNull( "transaction", txInfo.getTransaction() );
assertEquals( "read count", 0, lock.getReadCount() );
assertEquals( "write count", 1, lock.getWriteCount() );
assertEquals( "waiting thread count", 0, lock.getWaitingThreadsCount() );
}
List<LockInfo> locks = lockManager.getLocks();
assertEquals( "unexpected lock count", 0, locks.size() );
}
@Test
public void explicitLocksAffectTheLockCount()
{
try ( Transaction tx = graphDb.beginTx() )
{
Node root = graphDb.createNode();
Lock first = tx.acquireReadLock( root );
LockInfo lock = getSingleLock();
assertEquals( "read count", 1, lock.getReadCount() );
assertEquals( "write count", 1, lock.getWriteCount() );
tx.acquireReadLock( root );
lock = getSingleLock();
assertEquals( "read count", 2, lock.getReadCount() );
assertEquals( "write count", 1, lock.getWriteCount() );
tx.acquireWriteLock( root );
lock = getSingleLock();
assertEquals( "read count", 2, lock.getReadCount() );
assertEquals( "write count", 2, lock.getWriteCount() );
first.release();
lock = getSingleLock();
assertEquals( "read count", 1, lock.getReadCount() );
assertEquals( "write count", 2, lock.getWriteCount() );
}
List<LockInfo> locks = lockManager.getLocks();
assertEquals( "unexpected lock count", 0, locks.size() );
}
@Test
public void shouldCountContendedLocks() throws Exception
{
final Node node = createNode();
Thread thread = null;
try ( Transaction tx = graphDb.beginTx() )
{
tx.acquireReadLock( node );
assertEquals( "all locks", 1, lockManager.getLocks().size() );
assertEquals( "contended locks", 0, lockManager.getContendedLocks( 0 ).size() );
thread = new Thread()
{
@Override
public void run()
{
try( Transaction tx = graphDb.beginTx() )
{
tx.acquireWriteLock( node );
}
}
};
thread.start();
awaitWaitingStateIn( thread );
assertEquals( "all locks", 1, lockManager.getLocks().size() );
assertEquals( "contended locks", 1, lockManager.getContendedLocks( 0 ).size() );
LockInfo contended = lockManager.getContendedLocks( 0 ).get( 0 );
assertEquals( "resource type", ResourceType.NODE, contended.getResourceType() );
assertEquals( "resource id", Long.toString( node.getId() ), contended.getResourceId() );
assertEquals( "read count", 1, contended.getReadCount() );
assertEquals( "write count", 0, contended.getWriteCount() );
assertEquals( "number of waiting thread", 1, contended.getWaitingThreads().size() );
assertEquals( "waiting thread name", thread.getName(), contended.getWaitingThreads().get( 0 ).getThreadName() );
}
finally
{
if ( thread != null ) thread.join();
}
}
private Node createNode()
{
try( Transaction tx = graphDb.beginTx() )
{
Node node = graphDb.createNode();
tx.success();
return node;
}
}
private void awaitWaitingStateIn( Thread t )
{
while ( t.getState() != State.WAITING )
{
try
{
Thread.sleep( 1 );
}
catch ( InterruptedException e )
{
Thread.interrupted();
}
}
}
private LockInfo getSingleLock()
{
List<LockInfo> locks = lockManager.getLocks();
assertEquals( "unexpected lock count", 1, locks.size() );
LockInfo lock = locks.get( 0 );
assertNotNull( "null lock", lock );
return lock;
}
}