org.codehaus.groovy.transform.ReadWriteLockASTTransformation Maven / Gradle / Ivy
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Groovy: A powerful multi-faceted language for the JVM
/*
* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.codehaus.groovy.transform;
import groovy.transform.WithReadLock;
import groovy.transform.WithWriteLock;
import org.codehaus.groovy.GroovyBugError;
import org.codehaus.groovy.ast.ASTNode;
import org.codehaus.groovy.ast.AnnotatedNode;
import org.codehaus.groovy.ast.AnnotationNode;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.FieldNode;
import org.codehaus.groovy.ast.MethodNode;
import org.codehaus.groovy.ast.expr.Expression;
import org.codehaus.groovy.ast.expr.MethodCallExpression;
import org.codehaus.groovy.ast.stmt.Statement;
import org.codehaus.groovy.control.CompilePhase;
import org.codehaus.groovy.control.SourceUnit;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import static org.codehaus.groovy.ast.ClassHelper.make;
import static org.codehaus.groovy.ast.tools.GeneralUtils.block;
import static org.codehaus.groovy.ast.tools.GeneralUtils.callX;
import static org.codehaus.groovy.ast.tools.GeneralUtils.ctorX;
import static org.codehaus.groovy.ast.tools.GeneralUtils.stmt;
import static org.codehaus.groovy.ast.tools.GeneralUtils.tryCatchS;
import static org.codehaus.groovy.ast.tools.GeneralUtils.varX;
import static org.objectweb.asm.Opcodes.ACC_FINAL;
import static org.objectweb.asm.Opcodes.ACC_PRIVATE;
import static org.objectweb.asm.Opcodes.ACC_STATIC;
/**
* Handles generation of code for the {@code @}WithReadLock and {@code @}WithWriteLock annotation.
* This transformation adds an instance of ReentrantReadWriteLock to the class.
* Any method annotated with {@code @}WithReadLock will obtain a read lock and release it in a finally block.
* Any method annotated with {@code @}WithWriteLock will obtain a write lock and release it in a finally block.
* For more information see {@link WithReadLock} and {@link WithWriteLock}
*/
@GroovyASTTransformation(phase = CompilePhase.CANONICALIZATION)
public class ReadWriteLockASTTransformation extends AbstractASTTransformation {
private static final ClassNode READ_LOCK_TYPE = make(WithReadLock.class);
private static final ClassNode WRITE_LOCK_TYPE = make(WithWriteLock.class);
private static final ClassNode LOCK_TYPE = make(ReentrantReadWriteLock.class);
public static final String DEFAULT_STATIC_LOCKNAME = "$REENTRANTLOCK";
public static final String DEFAULT_INSTANCE_LOCKNAME = "$reentrantlock";
@Override
public void visit(ASTNode[] nodes, SourceUnit source) {
init(nodes, source);
AnnotatedNode parent = (AnnotatedNode) nodes[1];
AnnotationNode node = (AnnotationNode) nodes[0];
final boolean isWriteLock;
if (READ_LOCK_TYPE.equals(node.getClassNode())) {
isWriteLock = false;
} else if (WRITE_LOCK_TYPE.equals(node.getClassNode())) {
isWriteLock = true;
} else {
throw new GroovyBugError("Internal error: expecting [" + READ_LOCK_TYPE.getName() + ", " + WRITE_LOCK_TYPE.getName() + "]" + " but got: " + node.getClassNode().getName());
}
String myTypeName = "@" + node.getClassNode().getNameWithoutPackage();
String value = getMemberStringValue(node, "value");
if (parent instanceof MethodNode) {
MethodNode mNode = (MethodNode) parent;
ClassNode cNode = mNode.getDeclaringClass();
FieldNode lockExpr = determineLock(value, cNode, mNode.isStatic(), myTypeName);
if (lockExpr == null) return;
// get lock type
final MethodCallExpression lockType = callX(varX(lockExpr), isWriteLock ? "writeLock" : "readLock");
lockType.setImplicitThis(false);
MethodCallExpression acquireLock = callX(lockType, "lock");
acquireLock.setImplicitThis(false);
MethodCallExpression releaseLock = callX(lockType, "unlock");
releaseLock.setImplicitThis(false);
Statement originalCode = mNode.getCode();
mNode.setCode(block(stmt(acquireLock), tryCatchS(originalCode, stmt(releaseLock))));
}
}
private FieldNode determineLock(String value, ClassNode targetClass, boolean isStatic, String myTypeName) {
if (value != null && value.length() > 0 && !value.equalsIgnoreCase(DEFAULT_INSTANCE_LOCKNAME)) {
FieldNode existingLockField = targetClass.getDeclaredField(value);
if (existingLockField == null) {
addError("Error during " + myTypeName + " processing: lock field with name '" + value + "' not found in class " + targetClass.getName(), targetClass);
return null;
}
if (existingLockField.isStatic() != isStatic) {
addError("Error during " + myTypeName + " processing: lock field with name '" + value + "' should " + (isStatic ? "" : "not ") + "be static", existingLockField);
return null;
}
return existingLockField;
}
if (isStatic) {
FieldNode field = targetClass.getDeclaredField(DEFAULT_STATIC_LOCKNAME);
if (field == null) {
int visibility = ACC_PRIVATE | ACC_STATIC | ACC_FINAL;
field = targetClass.addField(DEFAULT_STATIC_LOCKNAME, visibility, LOCK_TYPE, createLockObject());
} else if (!field.isStatic()) {
addError("Error during " + myTypeName + " processing: " + DEFAULT_STATIC_LOCKNAME + " field must be static", field);
return null;
}
return field;
}
FieldNode field = targetClass.getDeclaredField(DEFAULT_INSTANCE_LOCKNAME);
if (field == null) {
int visibility = ACC_PRIVATE | ACC_FINAL;
field = targetClass.addField(DEFAULT_INSTANCE_LOCKNAME, visibility, LOCK_TYPE, createLockObject());
} else if (field.isStatic()) {
addError("Error during " + myTypeName + " processing: " + DEFAULT_INSTANCE_LOCKNAME + " field must not be static", field);
return null;
}
return field;
}
private static Expression createLockObject() {
return ctorX(LOCK_TYPE);
}
}