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Adapting the VarHandle Code to Best Practices

This commit is contained in:
Ali Dehghani 2020-05-31 23:20:10 +04:30
parent f5c5cc5290
commit 5b7dde1ae8
1 changed files with 41 additions and 41 deletions
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82
core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/varhandles/VariableHandlesUnitTest.java
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@ -6,8 +6,9 @@ import java.lang.invoke.MethodHandles;
import java.lang.invoke.VarHandle;
import static org.assertj.core.api.Assertions.assertThat;
import static org.junit.Assert.*;
public class VariableHandlesUnitTest {
public class VariableHandlesTest {
public int publicTestVariable = 1;
private int privateTestVariable = 1;
@ -18,25 +19,23 @@ public class VariableHandlesUnitTest {
@Test
public void whenVariableHandleForPublicVariableIsCreated_ThenItIsInitializedProperly() throws NoSuchFieldException, IllegalAccessException {
VarHandle publicIntHandle = MethodHandles
VarHandle PUBLIC_TEST_VARIABLE = MethodHandles
.lookup()
.in(VariableHandlesUnitTest.class)
.findVarHandle(VariableHandlesUnitTest.class, "publicTestVariable", int.class);
assertThat(publicIntHandle.coordinateTypes().size() == 1);
assertThat(publicIntHandle.coordinateTypes().get(0) == VariableHandlesUnitTest.class);
.in(VariableHandlesTest.class)
.findVarHandle(VariableHandlesTest.class, "publicTestVariable", int.class);
assertEquals(1, PUBLIC_TEST_VARIABLE.coordinateTypes().size());
assertEquals(VariableHandlesTest.class, PUBLIC_TEST_VARIABLE.coordinateTypes().get(0));
}
@Test
public void whenVariableHandleForPrivateVariableIsCreated_ThenItIsInitializedProperly() throws NoSuchFieldException, IllegalAccessException {
VarHandle privateIntHandle = MethodHandles
.privateLookupIn(VariableHandlesUnitTest.class, MethodHandles.lookup())
.findVarHandle(VariableHandlesUnitTest.class, "privateTestVariable", int.class);
assertThat(privateIntHandle.coordinateTypes().size() == 1);
assertThat(privateIntHandle.coordinateTypes().get(0) == VariableHandlesUnitTest.class);
VarHandle PRIVATE_TEST_VARIABLE = MethodHandles
.privateLookupIn(VariableHandlesTest.class, MethodHandles.lookup())
.findVarHandle(VariableHandlesTest.class, "privateTestVariable", int.class);
assertEquals(1, PRIVATE_TEST_VARIABLE.coordinateTypes().size());
assertEquals(VariableHandlesTest.class, PRIVATE_TEST_VARIABLE.coordinateTypes().get(0));
}
@Test
@ -44,63 +43,64 @@ public class VariableHandlesUnitTest {
VarHandle arrayVarHandle = MethodHandles
.arrayElementVarHandle(int[].class);
assertThat(arrayVarHandle.coordinateTypes().size() == 2);
assertThat(arrayVarHandle.coordinateTypes().get(0) == int[].class);
assertEquals(2, arrayVarHandle.coordinateTypes().size());
assertEquals(int[].class, arrayVarHandle.coordinateTypes().get(0));
}
@Test
public void givenVarHandle_whenGetIsInvoked_ThenValueOfVariableIsReturned() throws NoSuchFieldException, IllegalAccessException {
VarHandle publicIntHandle = MethodHandles
VarHandle PUBLIC_TEST_VARIABLE = MethodHandles
.lookup()
.in(VariableHandlesUnitTest.class)
.findVarHandle(VariableHandlesUnitTest.class, "publicTestVariable", int.class);
.in(VariableHandlesTest.class)
.findVarHandle(VariableHandlesTest.class, "publicTestVariable", int.class);
assertThat((int) publicIntHandle.get(this) == 1);
assertEquals(1, (int) PUBLIC_TEST_VARIABLE.get(this));
}
@Test
public void givenVarHandle_whenSetIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
VarHandle publicIntHandle = MethodHandles
VarHandle VARIABLE_TO_SET = MethodHandles
.lookup()
.in(VariableHandlesUnitTest.class)
.findVarHandle(VariableHandlesUnitTest.class, "variableToSet", int.class);
publicIntHandle.set(this, 15);
.in(VariableHandlesTest.class)
.findVarHandle(VariableHandlesTest.class, "variableToSet", int.class);
assertThat((int) publicIntHandle.get(this) == 15);
VARIABLE_TO_SET.set(this, 15);
assertEquals(15, (int) VARIABLE_TO_SET.get(this));
}
@Test
public void givenVarHandle_whenCompareAndSetIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
VarHandle publicIntHandle = MethodHandles
VarHandle VARIABLE_TO_COMPARE_AND_SET = MethodHandles
.lookup()
.in(VariableHandlesUnitTest.class)
.findVarHandle(VariableHandlesUnitTest.class, "variableToCompareAndSet", int.class);
publicIntHandle.compareAndSet(this, 1, 100);
.in(VariableHandlesTest.class)
.findVarHandle(VariableHandlesTest.class, "variableToCompareAndSet", int.class);
assertThat((int) publicIntHandle.get(this) == 100);
VARIABLE_TO_COMPARE_AND_SET.compareAndSet(this, 1, 100);
assertEquals(100, (int) VARIABLE_TO_COMPARE_AND_SET.get(this));
}
@Test
public void givenVarHandle_whenGetAndAddIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
VarHandle publicIntHandle = MethodHandles
VarHandle VARIABLE_TO_GET_AND_ADD = MethodHandles
.lookup()
.in(VariableHandlesUnitTest.class)
.findVarHandle(VariableHandlesUnitTest.class, "variableToGetAndAdd", int.class);
int before = (int) publicIntHandle.getAndAdd(this, 200);
.in(VariableHandlesTest.class)
.findVarHandle(VariableHandlesTest.class, "variableToGetAndAdd", int.class);
assertThat(before == 0);
assertThat((int) publicIntHandle.get(this) == 200);
int before = (int) VARIABLE_TO_GET_AND_ADD.getAndAdd(this, 200);
assertEquals(0, before);
assertEquals(200, (int) VARIABLE_TO_GET_AND_ADD.get(this));
}
@Test
public void givenVarHandle_whenGetAndBitwiseOrIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
VarHandle publicIntHandle = MethodHandles
VarHandle VARIABLE_TO_BITWISE_OR = MethodHandles
.lookup()
.in(VariableHandlesUnitTest.class)
.findVarHandle(VariableHandlesUnitTest.class, "variableToBitwiseOr", byte.class);
byte before = (byte) publicIntHandle.getAndBitwiseOr(this, (byte) 127);
.in(VariableHandlesTest.class)
.findVarHandle(VariableHandlesTest.class, "variableToBitwiseOr", byte.class);
byte before = (byte) VARIABLE_TO_BITWISE_OR.getAndBitwiseOr(this, (byte) 127);
assertThat(before == 0);
assertThat(variableToBitwiseOr == 127);
assertEquals(0, before);
assertEquals(127, (byte) VARIABLE_TO_BITWISE_OR.get(this));
}
}