jersey.repackaged.com.google.common.util.concurrent.Monitor Maven / Gradle / Ivy
/*
* Copyright (C) 2010 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package jersey.repackaged.com.google.common.util.concurrent;
import static jersey.repackaged.com.google.common.base.Preconditions.checkNotNull;
import jersey.repackaged.com.google.common.annotations.Beta;
import jersey.repackaged.com.google.common.base.Throwables;
import jersey.repackaged.com.google.common.collect.Lists;
import java.util.ArrayList;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
import javax.annotation.Nullable;
import javax.annotation.concurrent.GuardedBy;
/**
* A synchronization abstraction supporting waiting on arbitrary boolean conditions.
*
* This class is intended as a replacement for {@link ReentrantLock}. Code using {@code Monitor}
* is less error-prone and more readable than code using {@code ReentrantLock}, without significant
* performance loss. {@code Monitor} even has the potential for performance gain by optimizing the
* evaluation and signaling of conditions. Signaling is entirely
*
* implicit.
* By eliminating explicit signaling, this class can guarantee that only one thread is awakened
* when a condition becomes true (no "signaling storms" due to use of {@link
* java.util.concurrent.locks.Condition#signalAll Condition.signalAll}) and that no signals are lost
* (no "hangs" due to incorrect use of {@link java.util.concurrent.locks.Condition#signal
* Condition.signal}).
*
*
A thread is said to occupy a monitor if it has entered the monitor but not yet
* left. Only one thread may occupy a given monitor at any moment. A monitor is also
* reentrant, so a thread may enter a monitor any number of times, and then must leave the same
* number of times. The enter and leave operations have the same synchronization
* semantics as the built-in Java language synchronization primitives.
*
*
A call to any of the enter methods with void return type should always be
* followed immediately by a try/finally block to ensure that the current thread leaves the
* monitor cleanly:
{@code
*
* monitor.enter();
* try {
* // do things while occupying the monitor
* } finally {
* monitor.leave();
* }}
*
* A call to any of the enter methods with boolean return type should always appear as
* the condition of an if statement containing a try/finally block to ensure that the
* current thread leaves the monitor cleanly: {@code
*
* if (monitor.tryEnter()) {
* try {
* // do things while occupying the monitor
* } finally {
* monitor.leave();
* }
* } else {
* // do other things since the monitor was not available
* }}
*
* Comparison with {@code synchronized} and {@code ReentrantLock}
*
* The following examples show a simple threadsafe holder expressed using {@code synchronized},
* {@link ReentrantLock}, and {@code Monitor}.
*
*
{@code synchronized}
*
* This version is the fewest lines of code, largely because the synchronization mechanism used
* is built into the language and runtime. But the programmer has to remember to avoid a couple of
* common bugs: The {@code wait()} must be inside a {@code while} instead of an {@code if}, and
* {@code notifyAll()} must be used instead of {@code notify()} because there are two different
* logical conditions being awaited.
{@code
*
* public class SafeBox {
* private V value;
*
* public synchronized V get() throws InterruptedException {
* while (value == null) {
* wait();
* }
* V result = value;
* value = null;
* notifyAll();
* return result;
* }
*
* public synchronized void set(V newValue) throws InterruptedException {
* while (value != null) {
* wait();
* }
* value = newValue;
* notifyAll();
* }
* }}
*
* {@code ReentrantLock}
*
* This version is much more verbose than the {@code synchronized} version, and still suffers
* from the need for the programmer to remember to use {@code while} instead of {@code if}.
* However, one advantage is that we can introduce two separate {@code Condition} objects, which
* allows us to use {@code signal()} instead of {@code signalAll()}, which may be a performance
* benefit.
{@code
*
* public class SafeBox {
* private final ReentrantLock lock = new ReentrantLock();
* private final Condition valuePresent = lock.newCondition();
* private final Condition valueAbsent = lock.newCondition();
* private V value;
*
* public V get() throws InterruptedException {
* lock.lock();
* try {
* while (value == null) {
* valuePresent.await();
* }
* V result = value;
* value = null;
* valueAbsent.signal();
* return result;
* } finally {
* lock.unlock();
* }
* }
*
* public void set(V newValue) throws InterruptedException {
* lock.lock();
* try {
* while (value != null) {
* valueAbsent.await();
* }
* value = newValue;
* valuePresent.signal();
* } finally {
* lock.unlock();
* }
* }
* }}
*
* {@code Monitor}
*
* This version adds some verbosity around the {@code Guard} objects, but removes that same
* verbosity, and more, from the {@code get} and {@code set} methods. {@code Monitor} implements the
* same efficient signaling as we had to hand-code in the {@code ReentrantLock} version above.
* Finally, the programmer no longer has to hand-code the wait loop, and therefore doesn't have to
* remember to use {@code while} instead of {@code if}.
{@code
*
* public class SafeBox {
* private final Monitor monitor = new Monitor();
* private final Monitor.Guard valuePresent = new Monitor.Guard(monitor) {
* public boolean isSatisfied() {
* return value != null;
* }
* };
* private final Monitor.Guard valueAbsent = new Monitor.Guard(monitor) {
* public boolean isSatisfied() {
* return value == null;
* }
* };
* private V value;
*
* public V get() throws InterruptedException {
* monitor.enterWhen(valuePresent);
* try {
* V result = value;
* value = null;
* return result;
* } finally {
* monitor.leave();
* }
* }
*
* public void set(V newValue) throws InterruptedException {
* monitor.enterWhen(valueAbsent);
* try {
* value = newValue;
* } finally {
* monitor.leave();
* }
* }
* }}
*
* @author Justin T. Sampson
* @since 10.0
*/
@Beta
public final class Monitor {
// TODO: Use raw LockSupport or AbstractQueuedSynchronizer instead of ReentrantLock.
/**
* A boolean condition for which a thread may wait. A {@code Guard} is associated with a single
* {@code Monitor}. The monitor may check the guard at arbitrary times from any thread occupying
* the monitor, so code should not be written to rely on how often a guard might or might not be
* checked.
*
* If a {@code Guard} is passed into any method of a {@code Monitor} other than the one it is
* associated with, an {@link IllegalMonitorStateException} is thrown.
*
* @since 10.0
*/
@Beta
public abstract static class Guard {
final Monitor monitor;
final Condition condition;
@GuardedBy("monitor.lock")
int waiterCount = 0;
protected Guard(Monitor monitor) {
this.monitor = checkNotNull(monitor, "monitor");
this.condition = monitor.lock.newCondition();
}
/**
* Evaluates this guard's boolean condition. This method is always called with the associated
* monitor already occupied. Implementations of this method must depend only on state protected
* by the associated monitor, and must not modify that state.
*/
public abstract boolean isSatisfied();
@Override
public final boolean equals(Object other) {
// Overridden as final to ensure identity semantics in Monitor.activeGuards.
return this == other;
}
@Override
public final int hashCode() {
// Overridden as final to ensure identity semantics in Monitor.activeGuards.
return super.hashCode();
}
}
/**
* Whether this monitor is fair.
*/
private final boolean fair;
/**
* The lock underlying this monitor.
*/
private final ReentrantLock lock;
/**
* The guards associated with this monitor that currently have waiters ({@code waiterCount > 0}).
* This is an ArrayList rather than, say, a HashSet so that iteration and almost all adds don't
* incur any object allocation overhead.
*/
@GuardedBy("lock")
private final ArrayList activeGuards = Lists.newArrayListWithCapacity(1);
/**
* Creates a monitor with a non-fair (but fast) ordering policy. Equivalent to {@code
* Monitor(false)}.
*/
public Monitor() {
this(false);
}
/**
* Creates a monitor with the given ordering policy.
*
* @param fair whether this monitor should use a fair ordering policy rather than a non-fair (but
* fast) one
*/
public Monitor(boolean fair) {
this.fair = fair;
this.lock = new ReentrantLock(fair);
}
/**
* Enters this monitor. Blocks indefinitely.
*/
public void enter() {
lock.lock();
}
/**
* Enters this monitor. Blocks indefinitely, but may be interrupted.
*/
public void enterInterruptibly() throws InterruptedException {
lock.lockInterruptibly();
}
/**
* Enters this monitor. Blocks at most the given time.
*
* @return whether the monitor was entered
*/
public boolean enter(long time, TimeUnit unit) {
final ReentrantLock lock = this.lock;
if (!fair && lock.tryLock()) {
return true;
}
long startNanos = System.nanoTime();
long timeoutNanos = unit.toNanos(time);
long remainingNanos = timeoutNanos;
boolean interruptIgnored = false;
try {
while (true) {
try {
return lock.tryLock(remainingNanos, TimeUnit.NANOSECONDS);
} catch (InterruptedException ignored) {
interruptIgnored = true;
remainingNanos = (timeoutNanos - (System.nanoTime() - startNanos));
}
}
} finally {
if (interruptIgnored) {
Thread.currentThread().interrupt();
}
}
}
/**
* Enters this monitor. Blocks at most the given time, and may be interrupted.
*
* @return whether the monitor was entered
*/
public boolean enterInterruptibly(long time, TimeUnit unit) throws InterruptedException {
return lock.tryLock(time, unit);
}
/**
* Enters this monitor if it is possible to do so immediately. Does not block.
*
* Note: This method disregards the fairness setting of this monitor.
*
* @return whether the monitor was entered
*/
public boolean tryEnter() {
return lock.tryLock();
}
/**
* Enters this monitor when the guard is satisfied. Blocks indefinitely, but may be interrupted.
*/
public void enterWhen(Guard guard) throws InterruptedException {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
final ReentrantLock lock = this.lock;
boolean reentrant = lock.isHeldByCurrentThread();
boolean success = false;
lock.lockInterruptibly();
try {
waitInterruptibly(guard, reentrant);
success = true;
} finally {
if (!success) {
lock.unlock();
}
}
}
/**
* Enters this monitor when the guard is satisfied. Blocks indefinitely.
*/
public void enterWhenUninterruptibly(Guard guard) {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
final ReentrantLock lock = this.lock;
boolean reentrant = lock.isHeldByCurrentThread();
boolean success = false;
lock.lock();
try {
waitUninterruptibly(guard, reentrant);
success = true;
} finally {
if (!success) {
lock.unlock();
}
}
}
/**
* Enters this monitor when the guard is satisfied. Blocks at most the given time, including both
* the time to acquire the lock and the time to wait for the guard to be satisfied, and may be
* interrupted.
*
* @return whether the monitor was entered
*/
public boolean enterWhen(Guard guard, long time, TimeUnit unit) throws InterruptedException {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
final ReentrantLock lock = this.lock;
boolean reentrant = lock.isHeldByCurrentThread();
long remainingNanos;
if (!fair && lock.tryLock()) {
remainingNanos = unit.toNanos(time);
} else {
long startNanos = System.nanoTime();
if (!lock.tryLock(time, unit)) {
return false;
}
remainingNanos = unit.toNanos(time) - (System.nanoTime() - startNanos);
}
boolean satisfied = false;
try {
satisfied = waitInterruptibly(guard, remainingNanos, reentrant);
} finally {
if (!satisfied) {
lock.unlock();
}
}
return satisfied;
}
/**
* Enters this monitor when the guard is satisfied. Blocks at most the given time, including
* both the time to acquire the lock and the time to wait for the guard to be satisfied.
*
* @return whether the monitor was entered
*/
public boolean enterWhenUninterruptibly(Guard guard, long time, TimeUnit unit) {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
final ReentrantLock lock = this.lock;
boolean reentrant = lock.isHeldByCurrentThread();
boolean interruptIgnored = false;
try {
long remainingNanos;
if (!fair && lock.tryLock()) {
remainingNanos = unit.toNanos(time);
} else {
long startNanos = System.nanoTime();
long timeoutNanos = unit.toNanos(time);
remainingNanos = timeoutNanos;
while (true) {
try {
if (lock.tryLock(remainingNanos, TimeUnit.NANOSECONDS)) {
break;
} else {
return false;
}
} catch (InterruptedException ignored) {
interruptIgnored = true;
} finally {
remainingNanos = (timeoutNanos - (System.nanoTime() - startNanos));
}
}
}
boolean satisfied = false;
try {
satisfied = waitUninterruptibly(guard, remainingNanos, reentrant);
} finally {
if (!satisfied) {
lock.unlock();
}
}
return satisfied;
} finally {
if (interruptIgnored) {
Thread.currentThread().interrupt();
}
}
}
/**
* Enters this monitor if the guard is satisfied. Blocks indefinitely acquiring the lock, but
* does not wait for the guard to be satisfied.
*
* @return whether the monitor was entered
*/
public boolean enterIf(Guard guard) {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
final ReentrantLock lock = this.lock;
lock.lock();
boolean satisfied = false;
try {
satisfied = guard.isSatisfied();
} finally {
if (!satisfied) {
lock.unlock();
}
}
return satisfied;
}
/**
* Enters this monitor if the guard is satisfied. Blocks indefinitely acquiring the lock, but does
* not wait for the guard to be satisfied, and may be interrupted.
*
* @return whether the monitor was entered
*/
public boolean enterIfInterruptibly(Guard guard) throws InterruptedException {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
final ReentrantLock lock = this.lock;
lock.lockInterruptibly();
boolean satisfied = false;
try {
satisfied = guard.isSatisfied();
} finally {
if (!satisfied) {
lock.unlock();
}
}
return satisfied;
}
/**
* Enters this monitor if the guard is satisfied. Blocks at most the given time acquiring the
* lock, but does not wait for the guard to be satisfied.
*
* @return whether the monitor was entered
*/
public boolean enterIf(Guard guard, long time, TimeUnit unit) {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
final ReentrantLock lock = this.lock;
if (!enter(time, unit)) {
return false;
}
boolean satisfied = false;
try {
satisfied = guard.isSatisfied();
} finally {
if (!satisfied) {
lock.unlock();
}
}
return satisfied;
}
/**
* Enters this monitor if the guard is satisfied. Blocks at most the given time acquiring the
* lock, but does not wait for the guard to be satisfied, and may be interrupted.
*
* @return whether the monitor was entered
*/
public boolean enterIfInterruptibly(Guard guard, long time, TimeUnit unit)
throws InterruptedException {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
final ReentrantLock lock = this.lock;
if (!lock.tryLock(time, unit)) {
return false;
}
boolean satisfied = false;
try {
satisfied = guard.isSatisfied();
} finally {
if (!satisfied) {
lock.unlock();
}
}
return satisfied;
}
/**
* Enters this monitor if it is possible to do so immediately and the guard is satisfied. Does not
* block acquiring the lock and does not wait for the guard to be satisfied.
*
*
Note: This method disregards the fairness setting of this monitor.
*
* @return whether the monitor was entered
*/
public boolean tryEnterIf(Guard guard) {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
final ReentrantLock lock = this.lock;
if (!lock.tryLock()) {
return false;
}
boolean satisfied = false;
try {
satisfied = guard.isSatisfied();
} finally {
if (!satisfied) {
lock.unlock();
}
}
return satisfied;
}
/**
* Waits for the guard to be satisfied. Waits indefinitely, but may be interrupted. May be
* called only by a thread currently occupying this monitor.
*/
public void waitFor(Guard guard) throws InterruptedException {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
if (!lock.isHeldByCurrentThread()) {
throw new IllegalMonitorStateException();
}
waitInterruptibly(guard, true);
}
/**
* Waits for the guard to be satisfied. Waits indefinitely. May be called only by a thread
* currently occupying this monitor.
*/
public void waitForUninterruptibly(Guard guard) {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
if (!lock.isHeldByCurrentThread()) {
throw new IllegalMonitorStateException();
}
waitUninterruptibly(guard, true);
}
/**
* Waits for the guard to be satisfied. Waits at most the given time, and may be interrupted.
* May be called only by a thread currently occupying this monitor.
*
* @return whether the guard is now satisfied
*/
public boolean waitFor(Guard guard, long time, TimeUnit unit) throws InterruptedException {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
if (!lock.isHeldByCurrentThread()) {
throw new IllegalMonitorStateException();
}
return waitInterruptibly(guard, unit.toNanos(time), true);
}
/**
* Waits for the guard to be satisfied. Waits at most the given time. May be called only by a
* thread currently occupying this monitor.
*
* @return whether the guard is now satisfied
*/
public boolean waitForUninterruptibly(Guard guard, long time, TimeUnit unit) {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
if (!lock.isHeldByCurrentThread()) {
throw new IllegalMonitorStateException();
}
return waitUninterruptibly(guard, unit.toNanos(time), true);
}
/**
* Leaves this monitor. May be called only by a thread currently occupying this monitor.
*/
public void leave() {
final ReentrantLock lock = this.lock;
if (!lock.isHeldByCurrentThread()) {
throw new IllegalMonitorStateException();
}
try {
signalConditionsOfSatisfiedGuards(null);
} finally {
lock.unlock();
}
}
/**
* Returns whether this monitor is using a fair ordering policy.
*/
public boolean isFair() {
return lock.isFair();
}
/**
* Returns whether this monitor is occupied by any thread. This method is designed for use in
* monitoring of the system state, not for synchronization control.
*/
public boolean isOccupied() {
return lock.isLocked();
}
/**
* Returns whether the current thread is occupying this monitor (has entered more times than it
* has left).
*/
public boolean isOccupiedByCurrentThread() {
return lock.isHeldByCurrentThread();
}
/**
* Returns the number of times the current thread has entered this monitor in excess of the number
* of times it has left. Returns 0 if the current thread is not occupying this monitor.
*/
public int getOccupiedDepth() {
return lock.getHoldCount();
}
/**
* Returns an estimate of the number of threads waiting to enter this monitor. The value is only
* an estimate because the number of threads may change dynamically while this method traverses
* internal data structures. This method is designed for use in monitoring of the system state,
* not for synchronization control.
*/
public int getQueueLength() {
return lock.getQueueLength();
}
/**
* Returns whether any threads are waiting to enter this monitor. Note that because cancellations
* may occur at any time, a {@code true} return does not guarantee that any other thread will ever
* enter this monitor. This method is designed primarily for use in monitoring of the system
* state.
*/
public boolean hasQueuedThreads() {
return lock.hasQueuedThreads();
}
/**
* Queries whether the given thread is waiting to enter this monitor. Note that because
* cancellations may occur at any time, a {@code true} return does not guarantee that this thread
* will ever enter this monitor. This method is designed primarily for use in monitoring of the
* system state.
*/
public boolean hasQueuedThread(Thread thread) {
return lock.hasQueuedThread(thread);
}
/**
* Queries whether any threads are waiting for the given guard to become satisfied. Note that
* because timeouts and interrupts may occur at any time, a {@code true} return does not guarantee
* that the guard becoming satisfied in the future will awaken any threads. This method is
* designed primarily for use in monitoring of the system state.
*/
public boolean hasWaiters(Guard guard) {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
lock.lock();
try {
return guard.waiterCount > 0;
} finally {
lock.unlock();
}
}
/**
* Returns an estimate of the number of threads waiting for the given guard to become satisfied.
* Note that because timeouts and interrupts may occur at any time, the estimate serves only as an
* upper bound on the actual number of waiters. This method is designed for use in monitoring of
* the system state, not for synchronization control.
*/
public int getWaitQueueLength(Guard guard) {
if (guard.monitor != this) {
throw new IllegalMonitorStateException();
}
lock.lock();
try {
return guard.waiterCount;
} finally {
lock.unlock();
}
}
@GuardedBy("lock")
private void signalConditionsOfSatisfiedGuards(@Nullable Guard interruptedGuard) {
final ArrayList guards = this.activeGuards;
final int guardCount = guards.size();
try {
for (int i = 0; i < guardCount; i++) {
Guard guard = guards.get(i);
if ((guard == interruptedGuard) && (guard.waiterCount == 1)) {
// That one waiter was just interrupted and is throwing InterruptedException rather than
// paying attention to the guard being satisfied, so find another waiter on another guard.
continue;
}
if (guard.isSatisfied()) {
guard.condition.signal();
return;
}
}
} catch (Throwable throwable) {
for (int i = 0; i < guardCount; i++) {
Guard guard = guards.get(i);
guard.condition.signalAll();
}
throw Throwables.propagate(throwable);
}
}
@GuardedBy("lock")
private void incrementWaiters(Guard guard) {
int waiters = guard.waiterCount++;
if (waiters == 0) {
activeGuards.add(guard);
}
}
@GuardedBy("lock")
private void decrementWaiters(Guard guard) {
int waiters = --guard.waiterCount;
if (waiters == 0) {
activeGuards.remove(guard);
}
}
@GuardedBy("lock")
private void waitInterruptibly(Guard guard, boolean signalBeforeWaiting)
throws InterruptedException {
if (!guard.isSatisfied()) {
if (signalBeforeWaiting) {
signalConditionsOfSatisfiedGuards(null);
}
incrementWaiters(guard);
try {
final Condition condition = guard.condition;
do {
try {
condition.await();
} catch (InterruptedException interrupt) {
try {
signalConditionsOfSatisfiedGuards(guard);
} catch (Throwable throwable) {
Thread.currentThread().interrupt();
throw Throwables.propagate(throwable);
}
throw interrupt;
}
} while (!guard.isSatisfied());
} finally {
decrementWaiters(guard);
}
}
}
@GuardedBy("lock")
private void waitUninterruptibly(Guard guard, boolean signalBeforeWaiting) {
if (!guard.isSatisfied()) {
if (signalBeforeWaiting) {
signalConditionsOfSatisfiedGuards(null);
}
incrementWaiters(guard);
try {
final Condition condition = guard.condition;
do {
condition.awaitUninterruptibly();
} while (!guard.isSatisfied());
} finally {
decrementWaiters(guard);
}
}
}
@GuardedBy("lock")
private boolean waitInterruptibly(Guard guard, long remainingNanos, boolean signalBeforeWaiting)
throws InterruptedException {
if (!guard.isSatisfied()) {
if (signalBeforeWaiting) {
signalConditionsOfSatisfiedGuards(null);
}
incrementWaiters(guard);
try {
final Condition condition = guard.condition;
do {
if (remainingNanos <= 0) {
return false;
}
try {
remainingNanos = condition.awaitNanos(remainingNanos);
} catch (InterruptedException interrupt) {
try {
signalConditionsOfSatisfiedGuards(guard);
} catch (Throwable throwable) {
Thread.currentThread().interrupt();
throw Throwables.propagate(throwable);
}
throw interrupt;
}
} while (!guard.isSatisfied());
} finally {
decrementWaiters(guard);
}
}
return true;
}
@GuardedBy("lock")
private boolean waitUninterruptibly(Guard guard, long timeoutNanos,
boolean signalBeforeWaiting) {
if (!guard.isSatisfied()) {
long startNanos = System.nanoTime();
if (signalBeforeWaiting) {
signalConditionsOfSatisfiedGuards(null);
}
boolean interruptIgnored = false;
try {
incrementWaiters(guard);
try {
final Condition condition = guard.condition;
long remainingNanos = timeoutNanos;
do {
if (remainingNanos <= 0) {
return false;
}
try {
remainingNanos = condition.awaitNanos(remainingNanos);
} catch (InterruptedException ignored) {
try {
signalConditionsOfSatisfiedGuards(guard);
} catch (Throwable throwable) {
Thread.currentThread().interrupt();
throw Throwables.propagate(throwable);
}
interruptIgnored = true;
remainingNanos = (timeoutNanos - (System.nanoTime() - startNanos));
}
} while (!guard.isSatisfied());
} finally {
decrementWaiters(guard);
}
} finally {
if (interruptIgnored) {
Thread.currentThread().interrupt();
}
}
}
return true;
}
}