11d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2010 The Guava Authors 31d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 41d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Licensed under the Apache License, Version 2.0 (the "License"); 51d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * you may not use this file except in compliance with the License. 61d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * You may obtain a copy of the License at 71d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 81d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * http://www.apache.org/licenses/LICENSE-2.0 91d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Unless required by applicable law or agreed to in writing, software 111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * distributed under the License is distributed on an "AS IS" BASIS, 121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * See the License for the specific language governing permissions and 141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * limitations under the License. 151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpackage com.google.common.util.concurrent; 181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport static com.google.common.base.Preconditions.checkNotNull; 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.annotations.Beta; 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.base.Throwables; 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.Lists; 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.ArrayList; 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.concurrent.TimeUnit; 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.concurrent.locks.Condition; 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.concurrent.locks.ReentrantLock; 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport javax.annotation.Nullable; 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport javax.annotation.concurrent.GuardedBy; 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A synchronization abstraction supporting waiting on arbitrary boolean conditions. 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>This class is intended as a replacement for {@link ReentrantLock}. Code using {@code Monitor} 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * is less error-prone and more readable than code using {@code ReentrantLock}, without significant 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * performance loss. {@code Monitor} even has the potential for performance gain by optimizing the 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * evaluation and signaling of conditions. Signaling is entirely 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <a href="http://en.wikipedia.org/wiki/Monitor_(synchronization)#Implicit_signaling"> 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * implicit</a>. 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * By eliminating explicit signaling, this class can guarantee that only one thread is awakened 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * when a condition becomes true (no "signaling storms" due to use of {@link 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * java.util.concurrent.locks.Condition#signalAll Condition.signalAll}) and that no signals are lost 451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * (no "hangs" due to incorrect use of {@link java.util.concurrent.locks.Condition#signal 461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Condition.signal}). 471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>A thread is said to <i>occupy</i> a monitor if it has <i>entered</i> the monitor but not yet 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <i>left</i>. Only one thread may occupy a given monitor at any moment. A monitor is also 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * reentrant, so a thread may enter a monitor any number of times, and then must leave the same 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * number of times. The <i>enter</i> and <i>leave</i> operations have the same synchronization 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * semantics as the built-in Java language synchronization primitives. 531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>A call to any of the <i>enter</i> methods with <b>void</b> return type should always be 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * followed immediately by a <i>try/finally</i> block to ensure that the current thread leaves the 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * monitor cleanly: <pre> {@code 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * monitor.enter(); 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * try { 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * // do things while occupying the monitor 611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } finally { 621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * monitor.leave(); 631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * }}</pre> 641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A call to any of the <i>enter</i> methods with <b>boolean</b> return type should always appear as 661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * the condition of an <i>if</i> statement containing a <i>try/finally</i> block to ensure that the 671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * current thread leaves the monitor cleanly: <pre> {@code 681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * if (monitor.tryEnter()) { 701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * try { 711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * // do things while occupying the monitor 721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } finally { 731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * monitor.leave(); 741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } else { 761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * // do other things since the monitor was not available 771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * }}</pre> 781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <h2>Comparison with {@code synchronized} and {@code ReentrantLock}</h2> 801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>The following examples show a simple threadsafe holder expressed using {@code synchronized}, 821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@link ReentrantLock}, and {@code Monitor}. 831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <h3>{@code synchronized}</h3> 851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>This version is the fewest lines of code, largely because the synchronization mechanism used 871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * is built into the language and runtime. But the programmer has to remember to avoid a couple of 881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * common bugs: The {@code wait()} must be inside a {@code while} instead of an {@code if}, and 891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@code notifyAll()} must be used instead of {@code notify()} because there are two different 901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * logical conditions being awaited. <pre> {@code 911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * public class SafeBox<V> { 931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * private V value; 941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * public synchronized V get() throws InterruptedException { 961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * while (value == null) { 971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * wait(); 981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * V result = value; 1001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * value = null; 1011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * notifyAll(); 1021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * return result; 1031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * public synchronized void set(V newValue) throws InterruptedException { 1061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * while (value != null) { 1071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * wait(); 1081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * value = newValue; 1101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * notifyAll(); 1111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * }}</pre> 1131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <h3>{@code ReentrantLock}</h3> 1151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>This version is much more verbose than the {@code synchronized} version, and still suffers 1171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * from the need for the programmer to remember to use {@code while} instead of {@code if}. 1181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * However, one advantage is that we can introduce two separate {@code Condition} objects, which 1191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * allows us to use {@code signal()} instead of {@code signalAll()}, which may be a performance 1201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * benefit. <pre> {@code 1211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * public class SafeBox<V> { 1231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * private final ReentrantLock lock = new ReentrantLock(); 1241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * private final Condition valuePresent = lock.newCondition(); 1251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * private final Condition valueAbsent = lock.newCondition(); 1261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * private V value; 1271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * public V get() throws InterruptedException { 1291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * lock.lock(); 1301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * try { 1311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * while (value == null) { 1321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * valuePresent.await(); 1331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * V result = value; 1351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * value = null; 1361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * valueAbsent.signal(); 1371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * return result; 1381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } finally { 1391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * lock.unlock(); 1401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * public void set(V newValue) throws InterruptedException { 1441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * lock.lock(); 1451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * try { 1461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * while (value != null) { 1471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * valueAbsent.await(); 1481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * value = newValue; 1501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * valuePresent.signal(); 1511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } finally { 1521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * lock.unlock(); 1531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * }}</pre> 1561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <h3>{@code Monitor}</h3> 1581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>This version adds some verbosity around the {@code Guard} objects, but removes that same 1601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * verbosity, and more, from the {@code get} and {@code set} methods. {@code Monitor} implements the 1611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * same efficient signaling as we had to hand-code in the {@code ReentrantLock} version above. 1621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Finally, the programmer no longer has to hand-code the wait loop, and therefore doesn't have to 1631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * remember to use {@code while} instead of {@code if}. <pre> {@code 1641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * public class SafeBox<V> { 1661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * private final Monitor monitor = new Monitor(); 1671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * private final Monitor.Guard valuePresent = new Monitor.Guard(monitor) { 1681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * public boolean isSatisfied() { 1691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * return value != null; 1701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * }; 1721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * private final Monitor.Guard valueAbsent = new Monitor.Guard(monitor) { 1731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * public boolean isSatisfied() { 1741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * return value == null; 1751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * }; 1771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * private V value; 1781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * public V get() throws InterruptedException { 1801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * monitor.enterWhen(valuePresent); 1811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * try { 1821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * V result = value; 1831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * value = null; 1841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * return result; 1851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } finally { 1861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * monitor.leave(); 1871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 1901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * public void set(V newValue) throws InterruptedException { 1911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * monitor.enterWhen(valueAbsent); 1921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * try { 1931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * value = newValue; 1941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } finally { 1951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * monitor.leave(); 1961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * } 1981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * }}</pre> 1991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 2001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Justin T. Sampson 2011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 10.0 2021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 2031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert@Beta 2041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpublic final class Monitor { 2051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // TODO: Use raw LockSupport or AbstractQueuedSynchronizer instead of ReentrantLock. 2061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 2081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A boolean condition for which a thread may wait. A {@code Guard} is associated with a single 2091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@code Monitor}. The monitor may check the guard at arbitrary times from any thread occupying 2101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * the monitor, so code should not be written to rely on how often a guard might or might not be 2111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * checked. 2121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 2131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>If a {@code Guard} is passed into any method of a {@code Monitor} other than the one it is 2141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * associated with, an {@link IllegalMonitorStateException} is thrown. 2151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 2161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 10.0 2171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 2181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Beta 2191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public abstract static class Guard { 2201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final Monitor monitor; 2221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final Condition condition; 2231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @GuardedBy("monitor.lock") 2251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert int waiterCount = 0; 2261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert protected Guard(Monitor monitor) { 2281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this.monitor = checkNotNull(monitor, "monitor"); 2291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this.condition = monitor.lock.newCondition(); 2301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 2331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Evaluates this guard's boolean condition. This method is always called with the associated 2341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * monitor already occupied. Implementations of this method must depend only on state protected 2351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * by the associated monitor, and must not modify that state. 2361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 2371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public abstract boolean isSatisfied(); 2381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 2401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public final boolean equals(Object other) { 2411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // Overridden as final to ensure identity semantics in Monitor.activeGuards. 2421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this == other; 2431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 2461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public final int hashCode() { 2471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // Overridden as final to ensure identity semantics in Monitor.activeGuards. 2481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return super.hashCode(); 2491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 2541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Whether this monitor is fair. 2551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 2561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private final boolean fair; 2571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 2591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * The lock underlying this monitor. 2601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 2611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private final ReentrantLock lock; 2621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 2641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * The guards associated with this monitor that currently have waiters ({@code waiterCount > 0}). 2651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * This is an ArrayList rather than, say, a HashSet so that iteration and almost all adds don't 2661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * incur any object allocation overhead. 2671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 2681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @GuardedBy("lock") 2691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private final ArrayList<Guard> activeGuards = Lists.newArrayListWithCapacity(1); 2701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 2721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Creates a monitor with a non-fair (but fast) ordering policy. Equivalent to {@code 2731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Monitor(false)}. 2741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 2751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public Monitor() { 2761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this(false); 2771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 2801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Creates a monitor with the given ordering policy. 2811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 2821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @param fair whether this monitor should use a fair ordering policy rather than a non-fair (but 2831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * fast) one 2841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 2851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public Monitor(boolean fair) { 2861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this.fair = fair; 2871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this.lock = new ReentrantLock(fair); 2881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 2911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor. Blocks indefinitely. 2921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 2931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void enter() { 2941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.lock(); 2951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 2981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor. Blocks indefinitely, but may be interrupted. 2991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 3001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void enterInterruptibly() throws InterruptedException { 3011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.lockInterruptibly(); 3021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 3041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 3051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor. Blocks at most the given time. 3061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 3071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the monitor was entered 3081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 3091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean enter(long time, TimeUnit unit) { 3101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ReentrantLock lock = this.lock; 3111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!fair && lock.tryLock()) { 3121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return true; 3131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert long startNanos = System.nanoTime(); 3151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert long timeoutNanos = unit.toNanos(time); 3161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert long remainingNanos = timeoutNanos; 3171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean interruptIgnored = false; 3181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 3191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert while (true) { 3201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 3211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return lock.tryLock(remainingNanos, TimeUnit.NANOSECONDS); 3221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (InterruptedException ignored) { 3231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert interruptIgnored = true; 3241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert remainingNanos = (timeoutNanos - (System.nanoTime() - startNanos)); 3251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 3281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (interruptIgnored) { 3291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Thread.currentThread().interrupt(); 3301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 3341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 3351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor. Blocks at most the given time, and may be interrupted. 3361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 3371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the monitor was entered 3381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 3391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean enterInterruptibly(long time, TimeUnit unit) throws InterruptedException { 3401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return lock.tryLock(time, unit); 3411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 3431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 3441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor if it is possible to do so immediately. Does not block. 3451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 3461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p><b>Note:</b> This method disregards the fairness setting of this monitor. 3471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 3481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the monitor was entered 3491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 3501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean tryEnter() { 3511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return lock.tryLock(); 3521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 3541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 3551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor when the guard is satisfied. Blocks indefinitely, but may be interrupted. 3561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 3571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void enterWhen(Guard guard) throws InterruptedException { 3581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 3591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 3601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ReentrantLock lock = this.lock; 3621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean reentrant = lock.isHeldByCurrentThread(); 3631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean success = false; 3641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.lockInterruptibly(); 3651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 3661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert waitInterruptibly(guard, reentrant); 3671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert success = true; 3681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 3691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!success) { 3701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 3711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 3751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 3761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor when the guard is satisfied. Blocks indefinitely. 3771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 3781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void enterWhenUninterruptibly(Guard guard) { 3791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 3801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 3811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ReentrantLock lock = this.lock; 3831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean reentrant = lock.isHeldByCurrentThread(); 3841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean success = false; 3851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.lock(); 3861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 3871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert waitUninterruptibly(guard, reentrant); 3881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert success = true; 3891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 3901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!success) { 3911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 3921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 3951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 3961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 3971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor when the guard is satisfied. Blocks at most the given time, including both 3981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * the time to acquire the lock and the time to wait for the guard to be satisfied, and may be 3991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * interrupted. 4001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 4011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the monitor was entered 4021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 4031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean enterWhen(Guard guard, long time, TimeUnit unit) throws InterruptedException { 4041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 4051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 4061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ReentrantLock lock = this.lock; 4081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean reentrant = lock.isHeldByCurrentThread(); 4091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert long remainingNanos; 4101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!fair && lock.tryLock()) { 4111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert remainingNanos = unit.toNanos(time); 4121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } else { 4131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert long startNanos = System.nanoTime(); 4141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!lock.tryLock(time, unit)) { 4151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return false; 4161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert remainingNanos = unit.toNanos(time) - (System.nanoTime() - startNanos); 4181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean satisfied = false; 4201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 4211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert satisfied = waitInterruptibly(guard, remainingNanos, reentrant); 4221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 4231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!satisfied) { 4241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 4251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return satisfied; 4281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 4301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 4311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor when the guard is satisfied. Blocks at most the given time, including 4321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * both the time to acquire the lock and the time to wait for the guard to be satisfied. 4331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 4341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the monitor was entered 4351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 4361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean enterWhenUninterruptibly(Guard guard, long time, TimeUnit unit) { 4371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 4381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 4391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ReentrantLock lock = this.lock; 4411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean reentrant = lock.isHeldByCurrentThread(); 4421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean interruptIgnored = false; 4431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 4441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert long remainingNanos; 4451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!fair && lock.tryLock()) { 4461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert remainingNanos = unit.toNanos(time); 4471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } else { 4481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert long startNanos = System.nanoTime(); 4491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert long timeoutNanos = unit.toNanos(time); 4501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert remainingNanos = timeoutNanos; 4511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert while (true) { 4521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 4531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (lock.tryLock(remainingNanos, TimeUnit.NANOSECONDS)) { 4541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert break; 4551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } else { 4561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return false; 4571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (InterruptedException ignored) { 4591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert interruptIgnored = true; 4601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 4611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert remainingNanos = (timeoutNanos - (System.nanoTime() - startNanos)); 4621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean satisfied = false; 4661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 4671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert satisfied = waitUninterruptibly(guard, remainingNanos, reentrant); 4681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 4691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!satisfied) { 4701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 4711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return satisfied; 4741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 4751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (interruptIgnored) { 4761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Thread.currentThread().interrupt(); 4771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 4811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 4821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor if the guard is satisfied. Blocks indefinitely acquiring the lock, but 4831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * does not wait for the guard to be satisfied. 4841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 4851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the monitor was entered 4861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 4871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean enterIf(Guard guard) { 4881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 4891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 4901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 4911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ReentrantLock lock = this.lock; 4921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.lock(); 4931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean satisfied = false; 4941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 4951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert satisfied = guard.isSatisfied(); 4961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 4971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!satisfied) { 4981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 4991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return satisfied; 5021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 5041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 5051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor if the guard is satisfied. Blocks indefinitely acquiring the lock, but does 5061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * not wait for the guard to be satisfied, and may be interrupted. 5071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 5081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the monitor was entered 5091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 5101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean enterIfInterruptibly(Guard guard) throws InterruptedException { 5111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 5121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 5131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ReentrantLock lock = this.lock; 5151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.lockInterruptibly(); 5161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean satisfied = false; 5171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 5181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert satisfied = guard.isSatisfied(); 5191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 5201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!satisfied) { 5211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 5221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return satisfied; 5251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 5271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 5281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor if the guard is satisfied. Blocks at most the given time acquiring the 5291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * lock, but does not wait for the guard to be satisfied. 5301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 5311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the monitor was entered 5321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 5331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean enterIf(Guard guard, long time, TimeUnit unit) { 5341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 5351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 5361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ReentrantLock lock = this.lock; 5381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!enter(time, unit)) { 5391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return false; 5401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean satisfied = false; 5421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 5431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert satisfied = guard.isSatisfied(); 5441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 5451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!satisfied) { 5461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 5471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return satisfied; 5501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 5521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 5531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor if the guard is satisfied. Blocks at most the given time acquiring the 5541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * lock, but does not wait for the guard to be satisfied, and may be interrupted. 5551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 5561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the monitor was entered 5571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 5581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean enterIfInterruptibly(Guard guard, long time, TimeUnit unit) 5591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throws InterruptedException { 5601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 5611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 5621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ReentrantLock lock = this.lock; 5641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!lock.tryLock(time, unit)) { 5651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return false; 5661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean satisfied = false; 5681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 5691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert satisfied = guard.isSatisfied(); 5701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 5711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!satisfied) { 5721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 5731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return satisfied; 5761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 5781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 5791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Enters this monitor if it is possible to do so immediately and the guard is satisfied. Does not 5801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * block acquiring the lock and does not wait for the guard to be satisfied. 5811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 5821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p><b>Note:</b> This method disregards the fairness setting of this monitor. 5831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 5841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the monitor was entered 5851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 5861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean tryEnterIf(Guard guard) { 5871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 5881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 5891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ReentrantLock lock = this.lock; 5911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!lock.tryLock()) { 5921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return false; 5931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 5941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean satisfied = false; 5951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 5961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert satisfied = guard.isSatisfied(); 5971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 5981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!satisfied) { 5991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 6001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return satisfied; 6031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 6051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 6061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Waits for the guard to be satisfied. Waits indefinitely, but may be interrupted. May be 6071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * called only by a thread currently occupying this monitor. 6081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 6091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void waitFor(Guard guard) throws InterruptedException { 6101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 6111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 6121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!lock.isHeldByCurrentThread()) { 6141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 6151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert waitInterruptibly(guard, true); 6171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 6191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 6201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Waits for the guard to be satisfied. Waits indefinitely. May be called only by a thread 6211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * currently occupying this monitor. 6221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 6231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void waitForUninterruptibly(Guard guard) { 6241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 6251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 6261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!lock.isHeldByCurrentThread()) { 6281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 6291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert waitUninterruptibly(guard, true); 6311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 6331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 6341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Waits for the guard to be satisfied. Waits at most the given time, and may be interrupted. 6351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * May be called only by a thread currently occupying this monitor. 6361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 6371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the guard is now satisfied 6381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 6391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean waitFor(Guard guard, long time, TimeUnit unit) throws InterruptedException { 6401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 6411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 6421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!lock.isHeldByCurrentThread()) { 6441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 6451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return waitInterruptibly(guard, unit.toNanos(time), true); 6471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 6491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 6501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Waits for the guard to be satisfied. Waits at most the given time. May be called only by a 6511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * thread currently occupying this monitor. 6521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 6531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return whether the guard is now satisfied 6541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 6551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean waitForUninterruptibly(Guard guard, long time, TimeUnit unit) { 6561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 6571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 6581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!lock.isHeldByCurrentThread()) { 6601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 6611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return waitUninterruptibly(guard, unit.toNanos(time), true); 6631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 6651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 6661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Leaves this monitor. May be called only by a thread currently occupying this monitor. 6671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 6681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void leave() { 6691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ReentrantLock lock = this.lock; 6701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!lock.isHeldByCurrentThread()) { 6711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 6721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 6741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert signalConditionsOfSatisfiedGuards(null); 6751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 6761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 6771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 6801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 6811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Returns whether this monitor is using a fair ordering policy. 6821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 6831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean isFair() { 6841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return lock.isFair(); 6851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 6871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 6881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Returns whether this monitor is occupied by any thread. This method is designed for use in 6891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * monitoring of the system state, not for synchronization control. 6901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 6911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean isOccupied() { 6921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return lock.isLocked(); 6931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 6941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 6951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 6961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Returns whether the current thread is occupying this monitor (has entered more times than it 6971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * has left). 6981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 6991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean isOccupiedByCurrentThread() { 7001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return lock.isHeldByCurrentThread(); 7011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 7031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 7041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Returns the number of times the current thread has entered this monitor in excess of the number 7051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * of times it has left. Returns 0 if the current thread is not occupying this monitor. 7061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 7071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public int getOccupiedDepth() { 7081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return lock.getHoldCount(); 7091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 7111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 7121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Returns an estimate of the number of threads waiting to enter this monitor. The value is only 7131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * an estimate because the number of threads may change dynamically while this method traverses 7141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * internal data structures. This method is designed for use in monitoring of the system state, 7151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * not for synchronization control. 7161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 7171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public int getQueueLength() { 7181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return lock.getQueueLength(); 7191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 7211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 7221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Returns whether any threads are waiting to enter this monitor. Note that because cancellations 7231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * may occur at any time, a {@code true} return does not guarantee that any other thread will ever 7241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * enter this monitor. This method is designed primarily for use in monitoring of the system 7251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * state. 7261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 7271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean hasQueuedThreads() { 7281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return lock.hasQueuedThreads(); 7291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 7311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 7321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Queries whether the given thread is waiting to enter this monitor. Note that because 7331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * cancellations may occur at any time, a {@code true} return does not guarantee that this thread 7341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * will ever enter this monitor. This method is designed primarily for use in monitoring of the 7351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * system state. 7361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 7371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean hasQueuedThread(Thread thread) { 7381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return lock.hasQueuedThread(thread); 7391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 7411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 7421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Queries whether any threads are waiting for the given guard to become satisfied. Note that 7431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * because timeouts and interrupts may occur at any time, a {@code true} return does not guarantee 7441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * that the guard becoming satisfied in the future will awaken any threads. This method is 7451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * designed primarily for use in monitoring of the system state. 7461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 7471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public boolean hasWaiters(Guard guard) { 7481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 7491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 7501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.lock(); 7521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 7531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return guard.waiterCount > 0; 7541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 7551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 7561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 7591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 7601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Returns an estimate of the number of threads waiting for the given guard to become satisfied. 7611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Note that because timeouts and interrupts may occur at any time, the estimate serves only as an 7621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * upper bound on the actual number of waiters. This method is designed for use in monitoring of 7631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * the system state, not for synchronization control. 7641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 7651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public int getWaitQueueLength(Guard guard) { 7661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.monitor != this) { 7671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalMonitorStateException(); 7681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.lock(); 7701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 7711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return guard.waiterCount; 7721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 7731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert lock.unlock(); 7741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 7771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @GuardedBy("lock") 7781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private void signalConditionsOfSatisfiedGuards(@Nullable Guard interruptedGuard) { 7791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final ArrayList<Guard> guards = this.activeGuards; 7801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final int guardCount = guards.size(); 7811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 7821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert for (int i = 0; i < guardCount; i++) { 7831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Guard guard = guards.get(i); 7841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if ((guard == interruptedGuard) && (guard.waiterCount == 1)) { 7851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // That one waiter was just interrupted and is throwing InterruptedException rather than 7861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // paying attention to the guard being satisfied, so find another waiter on another guard. 7871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert continue; 7881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (guard.isSatisfied()) { 7901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert guard.condition.signal(); 7911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return; 7921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (Throwable throwable) { 7951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert for (int i = 0; i < guardCount; i++) { 7961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Guard guard = guards.get(i); 7971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert guard.condition.signalAll(); 7981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 7991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw Throwables.propagate(throwable); 8001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 8031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @GuardedBy("lock") 8041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private void incrementWaiters(Guard guard) { 8051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert int waiters = guard.waiterCount++; 8061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (waiters == 0) { 8071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert activeGuards.add(guard); 8081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 8111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @GuardedBy("lock") 8121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private void decrementWaiters(Guard guard) { 8131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert int waiters = --guard.waiterCount; 8141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (waiters == 0) { 8151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert activeGuards.remove(guard); 8161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 8191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @GuardedBy("lock") 8201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private void waitInterruptibly(Guard guard, boolean signalBeforeWaiting) 8211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throws InterruptedException { 8221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!guard.isSatisfied()) { 8231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (signalBeforeWaiting) { 8241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert signalConditionsOfSatisfiedGuards(null); 8251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert incrementWaiters(guard); 8271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 8281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final Condition condition = guard.condition; 8291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert do { 8301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 8311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert condition.await(); 8321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (InterruptedException interrupt) { 8331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 8341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert signalConditionsOfSatisfiedGuards(guard); 8351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (Throwable throwable) { 8361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Thread.currentThread().interrupt(); 8371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw Throwables.propagate(throwable); 8381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw interrupt; 8401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } while (!guard.isSatisfied()); 8421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 8431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert decrementWaiters(guard); 8441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 8481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @GuardedBy("lock") 8491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private void waitUninterruptibly(Guard guard, boolean signalBeforeWaiting) { 8501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!guard.isSatisfied()) { 8511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (signalBeforeWaiting) { 8521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert signalConditionsOfSatisfiedGuards(null); 8531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert incrementWaiters(guard); 8551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 8561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final Condition condition = guard.condition; 8571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert do { 8581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert condition.awaitUninterruptibly(); 8591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } while (!guard.isSatisfied()); 8601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 8611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert decrementWaiters(guard); 8621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 8661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @GuardedBy("lock") 8671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private boolean waitInterruptibly(Guard guard, long remainingNanos, boolean signalBeforeWaiting) 8681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throws InterruptedException { 8691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!guard.isSatisfied()) { 8701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (signalBeforeWaiting) { 8711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert signalConditionsOfSatisfiedGuards(null); 8721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert incrementWaiters(guard); 8741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 8751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final Condition condition = guard.condition; 8761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert do { 8771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (remainingNanos <= 0) { 8781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return false; 8791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 8811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert remainingNanos = condition.awaitNanos(remainingNanos); 8821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (InterruptedException interrupt) { 8831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 8841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert signalConditionsOfSatisfiedGuards(guard); 8851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (Throwable throwable) { 8861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Thread.currentThread().interrupt(); 8871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw Throwables.propagate(throwable); 8881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw interrupt; 8901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } while (!guard.isSatisfied()); 8921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 8931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert decrementWaiters(guard); 8941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return true; 8971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 8981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 8991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @GuardedBy("lock") 9001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private boolean waitUninterruptibly(Guard guard, long timeoutNanos, 9011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean signalBeforeWaiting) { 9021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!guard.isSatisfied()) { 9031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert long startNanos = System.nanoTime(); 9041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (signalBeforeWaiting) { 9051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert signalConditionsOfSatisfiedGuards(null); 9061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 9071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean interruptIgnored = false; 9081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 9091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert incrementWaiters(guard); 9101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 9111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final Condition condition = guard.condition; 9121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert long remainingNanos = timeoutNanos; 9131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert do { 9141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (remainingNanos <= 0) { 9151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return false; 9161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 9171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 9181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert remainingNanos = condition.awaitNanos(remainingNanos); 9191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (InterruptedException ignored) { 9201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 9211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert signalConditionsOfSatisfiedGuards(guard); 9221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (Throwable throwable) { 9231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Thread.currentThread().interrupt(); 9241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw Throwables.propagate(throwable); 9251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 9261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert interruptIgnored = true; 9271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert remainingNanos = (timeoutNanos - (System.nanoTime() - startNanos)); 9281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 9291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } while (!guard.isSatisfied()); 9301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 9311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert decrementWaiters(guard); 9321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 9331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } finally { 9341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (interruptIgnored) { 9351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Thread.currentThread().interrupt(); 9361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 9371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 9381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 9391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return true; 9401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 9411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 9421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 943