From 17972d59fa7e2eec6b73ba5da8234f5fa7ac2536 Mon Sep 17 00:00:00 2001
From: Roel Spilker <r.spilker@gmail.com>
Date: Mon, 17 Mar 2014 21:56:49 +0100
Subject: [#590][refactor] Fix for deadlock in WeakHashMap. Refactored all code
 that used a WeakHashMap to fake a field.

---
 src/utils/lombok/core/ReferenceFieldAugment.java | 218 +++++++++++++++++++++++
 1 file changed, 218 insertions(+)
 create mode 100644 src/utils/lombok/core/ReferenceFieldAugment.java

(limited to 'src/utils/lombok/core/ReferenceFieldAugment.java')

diff --git a/src/utils/lombok/core/ReferenceFieldAugment.java b/src/utils/lombok/core/ReferenceFieldAugment.java
new file mode 100644
index 00000000..214817a7
--- /dev/null
+++ b/src/utils/lombok/core/ReferenceFieldAugment.java
@@ -0,0 +1,218 @@
+/*
+ * Copyright (C) 2014 The Project Lombok Authors.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package lombok.core;
+
+import java.lang.ref.WeakReference;
+import java.util.Map;
+import java.util.WeakHashMap;
+
+public abstract class ReferenceFieldAugment<T, F> {
+	
+	/**
+	 * Augments a instance of a type with a reference field.
+	 * <p>
+	 * If the type already declares an instance field with the given name and field type, that field might be used. Otherwise the field will be augmented.
+	 * <p>
+	 * This code assumes that for any combination of {@code type} and {@code name} this method is only called once.
+	 * Otherwise, whether state is shared is undefined.
+	 * 
+	 * @param type to augment
+	 * @param fieldType type of the field
+	 * @param name of the field
+	 * @throws NullPointerException if {@code type}, {@code fieldType} or {@code name} is {@code null}
+	 */
+	public static <T, F> ReferenceFieldAugment<T, F> augment(Class<T> type, Class<? super F> fieldType, String name) {
+		return new MapFieldAugment<T, F>();
+	}
+	
+	/**
+	 * Augments a instance of a type with a weak reference field.
+	 * <p>
+	 * If the type already declares an instance field with the given name and field type, that field might be used. Otherwise the field will be augmented.
+	 * <p>
+	 * This code assumes that for any combination of {@code type} and {@code name} this method is only called once.
+	 * Otherwise, whether state is shared is undefined.
+	 * 
+	 * @param type to augment
+	 * @param fieldType type of the field
+	 * @param name of the field
+	 * @throws NullPointerException if {@code type}, {@code fieldType} or {@code name} is {@code null}
+	 */
+	public static <T, F> ReferenceFieldAugment<T, F> augmentWeakField(Class<T> type, Class<? super F> fieldType, String name) {
+		return new MapWeakFieldAugment<T, F>();
+	}
+	
+	private ReferenceFieldAugment() {
+		// prevent external instantiation
+	}
+	
+	/**
+	 * @throws NullPointerException if {@code object} is {@code null}
+	 */
+	public abstract F get(T object);
+	
+	/**
+	 * @throws NullPointerException if {@code object} or {@code expected} is {@code null}
+	 */
+	public final void set(T object, F value) {
+		getAndSet(object, value);
+	}
+	
+	/**
+	 * @return the value of the field <strong>before</strong> the operation.
+	 * @throws NullPointerException if {@code object} or {@code expected} is {@code null}
+	 */
+	public abstract F getAndSet(T object, F value);
+	
+	/**
+	 * @return the value of the field <strong>before</strong> the operation.
+	 * @throws NullPointerException if {@code object} is {@code null}
+	 */
+	public abstract F clear(T object);
+	
+	/**
+	 * @return the value of the field <strong>after</strong> the operation. If the value was equal to {@code expected} or already cleared {@code null}, otherwise the current value.
+	 * @throws NullPointerException if {@code object} or {@code expected} is {@code null}
+	 */
+	public abstract F compareAndClear(T object, F expected);
+	
+	/**
+	 * @return the value of the field <strong>after</strong> the operation.
+	 * @throws NullPointerException if {@code object} or {@code value} is {@code null}
+	 */
+	public abstract F setIfAbsent(T object, F value);
+	
+	/**
+	 * @return the value of the field <strong>after</strong> the operation.
+	 * @throws NullPointerException if {@code object}, {@code expected} or {@code value} is {@code null}
+	 */
+	public abstract F compareAndSet(T object, F expected, F value);
+	
+	private static class MapFieldAugment<T, F> extends ReferenceFieldAugment<T, F> {
+		final Map<T, Object> values = new WeakHashMap<T, Object>();
+		
+		@Override
+		public F get(T object) {
+			checkNotNull(object, "object");
+			synchronized (values) {
+				return read(object);
+			}
+		}
+		
+		@Override
+		public F getAndSet(T object, F value) {
+			checkNotNull(object, "object");
+			checkNotNull(value, "value");
+			synchronized (values) {
+				F result = read(object);
+				write(object, value);
+				return result;
+			}
+		}
+		
+		@Override
+		public F clear(T object) {
+			checkNotNull(object, "object");
+			synchronized (values) {
+				F result = read(object);
+				values.remove(object);
+				return result;
+			}
+		}
+		
+		@Override
+		public F compareAndClear(T object, F expected) {
+			checkNotNull(object, "object");
+			checkNotNull(expected, "expected");
+			synchronized (values) {
+				F result = read(object);
+				if (result == null) {
+					return null;
+				}
+				if (!expected.equals(result)) {
+					return result;
+				}
+				values.remove(object);
+				return null;
+			}
+		}
+		
+		@Override
+		public F setIfAbsent(T object, F value) {
+			checkNotNull(object, "object");
+			checkNotNull(value, "value");
+			synchronized (values) {
+				F result = read(object);
+				if (result != null) {
+					return result;
+				}
+				write(object, value);
+				return value;
+			}
+		}
+		
+		@Override
+		public F compareAndSet(T object, F expected, F value) {
+			checkNotNull(object, "object");
+			checkNotNull(expected, "expected");
+			checkNotNull(value, "value");
+			synchronized (values) {
+				F result = read(object);
+				if (!expected.equals(result)) {
+					return result;
+				}
+				write(object, value);
+				return value;
+			}
+		}
+		
+		@SuppressWarnings("unchecked")
+		F read(T object) {
+			return (F)values.get(object);
+		}
+		
+		void write(T object, F value) {
+			values.put(object, value);
+		}
+	}
+	
+	static class MapWeakFieldAugment<T, F> extends MapFieldAugment<T, F> {
+		
+		@SuppressWarnings("unchecked")
+		F read(T object) {
+			WeakReference<F> read = (WeakReference<F>)values.get(object);
+			if (read == null) return null;
+			F result = read.get();
+			if (result == null) values.remove(object);
+			return result;
+		}
+		
+		void write(T object, F value) {
+			values.put(object, new WeakReference<F>(value));
+		}
+	}
+	
+	private static <T> T checkNotNull(T object, String name) {
+		if (object == null) throw new NullPointerException(name);
+		return object;
+	}
+}
-- 
cgit