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cardilcardil
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Fixing lazy sync problem
Using properly Double-checked locking pattern for Lazy and SerializableLazy classes. Additionally, adding more test to cover the introduced code.
1 parent 67c1ca6 commit e5c8aa9

5 files changed

Lines changed: 192 additions & 20 deletions

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‎src/main/java/pl/wavesoftware/eid/impl/Lazy.java‎

Lines changed: 8 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -24,7 +24,7 @@
2424
* @since 2.0.0
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*/
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class Lazy<T> implements Supplier<T> {
27-
private Supplier<T> supplier;
27+
private volatile Supplier<T> supplier;
2828
private T value;
2929

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Lazy(Supplier<T> supplier) {
@@ -50,16 +50,13 @@ static <R> Lazy<R> of(R value) {
5050
@Override
5151
public T get() {
5252
if (supplier != null) {
53-
value = doGet();
54-
}
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return value;
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}
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58-
private synchronized T doGet() {
59-
if (supplier != null) {
60-
T calculated = supplier.get();
61-
supplier = null;
62-
return calculated;
53+
synchronized (this) {
54+
if (supplier != null) {
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T calculated = supplier.get();
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supplier = null;
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value = calculated;
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}
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}
6360
}
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return value;
6562
}

‎src/main/java/pl/wavesoftware/eid/impl/SerializableLazy.java‎

Lines changed: 6 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -29,7 +29,7 @@ final class SerializableLazy<T extends Serializable>
2929
implements SerializableSupplier<T> {
3030

3131
private static final long serialVersionUID = 20181124011908L;
32-
private T serializable;
32+
private volatile T serializable;
3333

3434
private SerializableLazy(Supplier<T> supplier) {
3535
super(supplier);
@@ -42,14 +42,11 @@ static <R extends Serializable> SerializableLazy<R> serializableOf(Supplier<R> s
4242
@Override
4343
public T get() {
4444
if (serializable == null) {
45-
serializable = doGetFromParent();
46-
}
47-
return serializable;
48-
}
49-
50-
private synchronized T doGetFromParent() {
51-
if (serializable == null) {
52-
return super.get();
45+
synchronized (this) {
46+
if (serializable == null) {
47+
serializable = super.get();
48+
}
49+
}
5350
}
5451
return serializable;
5552
}

‎src/test/java/pl/wavesoftware/eid/impl/DefaultFormatterTest.java‎

Lines changed: 87 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,87 @@
1+
/*
2+
* Copyright (c) 2018 Wave Software
3+
*
4+
* Licensed under the Apache License, Version 2.0 (the "License");
5+
* you may not use this file except in compliance with the License.
6+
* You may obtain a copy of the License at
7+
*
8+
* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
11+
* distributed under the License is distributed on an "AS IS" BASIS,
12+
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13+
* See the License for the specific language governing permissions and
14+
* limitations under the License.
15+
*/
16+
17+
package pl.wavesoftware.eid.impl;
18+
19+
import org.junit.After;
20+
import org.junit.Before;
21+
import org.junit.Test;
22+
import pl.wavesoftware.eid.Eid;
23+
import pl.wavesoftware.eid.configuration.Configuration;
24+
import pl.wavesoftware.eid.configuration.ConfigurationBuilder;
25+
import pl.wavesoftware.eid.configuration.Configurator;
26+
import pl.wavesoftware.eid.configuration.Formatter;
27+
import pl.wavesoftware.eid.configuration.UniqueIdGenerator;
28+
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import static org.assertj.core.api.Assertions.assertThat;
30+
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/**
32+
* @author <a href="mailto:krzysztof.suszynski@wavesoftware.pl">Krzysztof Suszynski</a>
33+
* @since 2018-12-03
34+
*/
35+
public class DefaultFormatterTest {
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37+
private Configurator restore;
38+
39+
@Before
40+
public void before() {
41+
restore = Eid.getBinding().getConfigurationSystem().configure(new Configurator() {
42+
@Override
43+
public void configure(ConfigurationBuilder configuration) {
44+
configuration.uniqueIdGenerator(new UniqueIdGenerator() {
45+
@Override
46+
public String generateUniqId() {
47+
return "deadcafe";
48+
}
49+
});
50+
}
51+
});
52+
}
53+
54+
@After
55+
public void after() {
56+
Eid.getBinding().getConfigurationSystem().configure(restore);
57+
}
58+
59+
@Test
60+
public void format() {
61+
// given
62+
Configuration configuration = new ConfigurationImpl();
63+
Formatter formatter = new DefaultFormatter(configuration);
64+
65+
// when
66+
String formatted = formatter.format(new Eid("20181203:224055"));
67+
68+
// then
69+
assertThat(formatted).isEqualTo("[20181203:224055]<deadcafe>");
70+
}
71+
72+
@Test
73+
public void formatWithMessage() {
74+
// given
75+
Configuration configuration = new ConfigurationImpl();
76+
Formatter formatter = new DefaultFormatter(configuration);
77+
78+
// when
79+
String formatted = formatter.format(
80+
new Eid("20181203:224137"),
81+
"a message"
82+
);
83+
84+
// then
85+
assertThat(formatted).isEqualTo("[20181203:224137]<deadcafe> => a message");
86+
}
87+
}

‎src/test/java/pl/wavesoftware/eid/impl/InternalChecksTest.java‎

Lines changed: 47 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,47 @@
1+
/*
2+
* Copyright (c) 2018 Wave Software
3+
*
4+
* Licensed under the Apache License, Version 2.0 (the "License");
5+
* you may not use this file except in compliance with the License.
6+
* You may obtain a copy of the License at
7+
*
8+
* http://www.apache.org/licenses/LICENSE-2.0
9+
*
10+
* Unless required by applicable law or agreed to in writing, software
11+
* distributed under the License is distributed on an "AS IS" BASIS,
12+
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13+
* See the License for the specific language governing permissions and
14+
* limitations under the License.
15+
*/
16+
17+
package pl.wavesoftware.eid.impl;
18+
19+
import org.junit.Rule;
20+
import org.junit.Test;
21+
import org.junit.rules.ExpectedException;
22+
23+
import static org.assertj.core.api.Assertions.*;
24+
25+
/**
26+
* @author <a href="mailto:krzysztof.suszynski@wavesoftware.pl">Krzysztof Suszynski</a>
27+
* @since 2018-12-03
28+
*/
29+
public class InternalChecksTest {
30+
31+
@Rule
32+
public ExpectedException expectedException = ExpectedException.none();
33+
34+
@Test
35+
public void testCheckNotNull() {
36+
// given
37+
String eid = "20181203:223812";
38+
String val = System.getProperty("non-existing-key-in-system");
39+
40+
// then
41+
expectedException.expect(IllegalArgumentException.class);
42+
expectedException.expectMessage(eid);
43+
44+
// when
45+
InternalChecks.checkNotNull(val, eid);
46+
}
47+
}

‎src/test/java/pl/wavesoftware/eid/impl/MessageSupplierTest.java‎

Lines changed: 44 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,44 @@
1+
/*
2+
* Copyright (c) 2018 Wave Software
3+
*
4+
* Licensed under the Apache License, Version 2.0 (the "License");
5+
* you may not use this file except in compliance with the License.
6+
* You may obtain a copy of the License at
7+
*
8+
* http://www.apache.org/licenses/LICENSE-2.0
9+
*
10+
* Unless required by applicable law or agreed to in writing, software
11+
* distributed under the License is distributed on an "AS IS" BASIS,
12+
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13+
* See the License for the specific language governing permissions and
14+
* limitations under the License.
15+
*/
16+
17+
package pl.wavesoftware.eid.impl;
18+
19+
import org.junit.Test;
20+
import pl.wavesoftware.eid.configuration.Configuration;
21+
22+
import static org.assertj.core.api.Assertions.assertThat;
23+
24+
/**
25+
* @author <a href="mailto:krzysztof.suszynski@wavesoftware.pl">Krzysztof Suszynski</a>
26+
* @since 2018-12-03
27+
*/
28+
public class MessageSupplierTest {
29+
30+
@Test
31+
public void testGet() {
32+
// given
33+
Configuration configuration = new ConfigurationImpl();
34+
MessageSupplier supplier = new MessageSupplier(
35+
configuration, "{0} -> 11", new Object[] { ".5" }
36+
);
37+
38+
// when
39+
String message = supplier.get();
40+
41+
// then
42+
assertThat(message).isEqualTo(".5 -> 11");
43+
}
44+
}

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