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72 lines
1.7 KiB
72 lines
1.7 KiB
/*
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* Copyright (c) 2016 - present Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under the BSD style license found in the
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* LICENSE file in the root directory of this source tree. An additional grant
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* of patent rights can be found in the PATENTS file in the same directory.
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*/
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import javax.annotation.concurrent.ThreadSafe;
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@ThreadSafe
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public class Constructors {
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int field;
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static Object staticField;
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public Constructors(int i) {
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field = i; // ok
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}
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public Constructors() {
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staticField = new Object(); // not ok;
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}
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private Constructors(Object o) {
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staticField = o; // ok because this is private
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}
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public Constructors(Constructors o) {
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o.field = 42; // not ok
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}
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public Constructors(String s) {
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calledFromConstructorOk(); // ok
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}
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private void calledFromConstructorOk() {
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this.field = 7;
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}
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public static synchronized Constructors singleton1Ok() {
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// ok because lock is held during write to static field in constructor
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return new Constructors(new Object());
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}
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private static Constructors sSingleton1;
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public static Constructors FP_singleton2Ok() {
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synchronized (Constructors.class) {
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if (sSingleton1 != null) {
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sSingleton1 = new Constructors(0);
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}
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}
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return sSingleton1; // not currently smart enough to understand that this read is ok
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}
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public static Constructors singleton1Bad() {
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// not ok because no lock is held
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return new Constructors(new Object());
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}
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private static Constructors sSingleton2;
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public static Constructors singleton2Bad() {
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if (sSingleton2 == null) {
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sSingleton2 = new Constructors(0);
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}
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return sSingleton2;
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}
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}
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