Modifier and Type	Class and Description
private static class	CountUpDownLatch.Sync Synchronization control For `CountUpDownLatch`.

Modifier and Type	Field and Description
private final CountUpDownLatch.Sync	sync

Access	Constructor and Description
public	CountUpDownLatch() Default constructor.
public	CountUpDownLatch(int the initial `count` initialCount) Constructs a new `CountUpDownLatch` initialized with the given `initialCount`.

Method Summary

Modifier and Type	Method and Description
public void	await() Causes the current thread to wait until `count` reaches zero, unless the thread is interrupted.
public boolean	Returns: `true` if the count reached zero and `false` if the waiting time elapsed before the count reached zero await(long the maximum time to wait timeout, TimeUnit the time unit of the `timeout` argument unit) Causes the current thread to wait until `count` reaches zero, unless the thread is interrupted, or the specified waiting time elapses.
public boolean	Returns: `true` if `count` transitions to zero countDown() Decrements the count of the latch, releasing all waiting threads if the count transitions to zero.
public boolean	Returns: `true` if `count` transitions to zero countDown(int by which to decrement the `count` amount) Decrements the `count` of the latch by the given `amount`, releasing all waiting threads if `count` transitions to zero.
public boolean	Returns: `true` if `count` transitioned from zero to a new value countUp() Increments the count of the latch.
public boolean	Returns: `true` if `count` transitioned from zero to a new value countUp(int by which to increment `count` amount) Increments the count of the latch by the given `amount`.
public boolean	Returns: if and only if `this == obj` equals(final CountUpDownLatch to test. other) Returns true if and only if `this` and `obj` refer to the same object (`this == obj` has the value `true`).
public boolean	Returns: if and only if `this == obj` equals(Object to test. obj) Overrides java.lang.Object.equals. Returns true if and only if `this` and `obj` refer to the same object (`this == obj` has the value `true`).
public int	Returns: the current count getCount() Returns the current count.
public int	Returns: a hash code value for this latch. This method is supported for the benefit of hash tables hashCode() Overrides java.lang.Object.hashCode. As much as is reasonably practical, returns distinct integers for distinct objects.
public boolean	Returns: `true` if `count` transitions to zero. setCount(int to which to update `count`; must be non-negative. newCount) Updates `count` to the requested `newCount`, returning `true` on transition to zero.
public String	Returns: a string identifying this latch, as well as its current `count`. toString() Overrides java.lang.Object.toString. Returns a string representation of this object.

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll wait wait wait

Field Detail

sync	back to summary
private final CountUpDownLatch.Sync sync

Constructor Detail

CountUpDownLatch back to summary

CountUpDownLatch	back to summary
public CountUpDownLatch() Default constructor. Equivalent to `new` `CountUpDownLatch(0)`

public CountUpDownLatch()

Default constructor.

Equivalent to new CountUpDownLatch(0)

CountUpDownLatch back to summary

CountUpDownLatch	back to summary
public CountUpDownLatch(int initialCount) Constructs a new `CountUpDownLatch` initialized with the given `initialCount`. Parameters initialCount:int the initial `count` Exceptions IllegalArgumentException: if `initialCount` is negative

public CountUpDownLatch(int initialCount)

Constructs a new CountUpDownLatch initialized with the given initialCount.

Parameters

initialCount:int: the initial count

Exceptions

IllegalArgumentException:: if initialCount is negative

Method Detail

await back to summary

await	back to summary
public void await() throws InterruptedException Causes the current thread to wait until `count` reaches zero, unless the thread is interrupted. If the current `count` is already zero, then this method returns immediately. If the current `count` is greater than zero, then the current thread becomes disabled for thread scheduling purposes and lies dormant until either: The count reaches zero due an invocation of `countDown()`, `countDown(int`}, or `setCount(int)`. Some other thread interrupts the current thread. If the current thread: has its interrupted status set on entry to this method; or is interrupted while waiting, then `InterruptedException` is thrown and the current thread's interrupted status is cleared. Exceptions InterruptedException: if the current thread is interrupted while waiting

public void await() throws InterruptedException

Causes the current thread to wait until count reaches zero, unless the thread is interrupted.

If the current count is already zero, then this method returns immediately.

If the current count is greater than zero, then the current thread becomes disabled for thread scheduling purposes and lies dormant until either:

The count reaches zero due an invocation of countDown(), countDown(int}, or setCount(int).
Some other thread interrupts the current thread.

If the current thread:

has its interrupted status set on entry to this method; or
is interrupted while waiting,

then InterruptedException is thrown and the current thread's interrupted status is cleared.

Exceptions

InterruptedException:: if the current thread is interrupted while waiting

await back to summary

await	back to summary
public boolean await(long timeout, TimeUnit unit) throws InterruptedException Causes the current thread to wait until `count` reaches zero, unless the thread is interrupted, or the specified waiting time elapses. If the current `count` is zero, then this method returns immediately with the value `true`. If the current `count` is greater than zero, then the current thread becomes disabled for thread scheduling purposes and lies dormant until either: The `count` reaches zero due to an invocation of `countDown()`, `countDown(int`}, or `setCount(int)` setCount(int)} Some other thread interrupts the current thread The specified waiting time elapses. If the count reaches zero then the method returns with the value `true`. If the current thread: has its interrupted status set on entry to this method; or is interrupted while waiting, then `InterruptedException` is thrown and the current thread's interrupted status is cleared. If the specified waiting time elapses then the value `false` is returned. If the time is less than or equal to zero, the method will not wait at all. Parameters timeout:long the maximum time to wait unit:TimeUnit the time unit of the `timeout` argument Returns:boolean `true` if the count reached zero and `false` if the waiting time elapsed before the count reached zero Exceptions InterruptedException: if the current thread is interrupted while waiting

public boolean await(long timeout, TimeUnit unit) throws InterruptedException

Causes the current thread to wait until count reaches zero, unless the thread is interrupted, or the specified waiting time elapses.

If the current count is zero, then this method returns immediately with the value true.

If the current count is greater than zero, then the current thread becomes disabled for thread scheduling purposes and lies dormant until either:

The count reaches zero due to an invocation of countDown(), countDown(int}, or setCount(int) setCount(int)}
Some other thread interrupts the current thread
The specified waiting time elapses.

If the count reaches zero then the method returns with the value true.

If the current thread:

has its interrupted status set on entry to this method; or
is interrupted while waiting,

then InterruptedException is thrown and the current thread's interrupted status is cleared.

If the specified waiting time elapses then the value false is returned. If the time is less than or equal to zero, the method will not wait at all.

Parameters

timeout:long: the maximum time to wait
unit:TimeUnit: the time unit of the timeout argument

Returns:boolean

true if the count reached zero and false if the waiting time elapsed before the count reached zero

Exceptions

InterruptedException:: if the current thread is interrupted while waiting

countDown back to summary

countDown	back to summary
public boolean countDown() Decrements the count of the latch, releasing all waiting threads if the count transitions to zero. If the current count is zero, no action occurs and false is returned immediately; Returns:boolean `true` if `count` transitions to zero

public boolean countDown()

Decrements the count of the latch, releasing all waiting threads if the count transitions to zero.

If the current count is zero, no action occurs and false is returned immediately;

Returns:boolean: true if count transitions to zero

countDown back to summary

countDown	back to summary
public boolean countDown(int amount) Decrements the `count` of the latch by the given `amount`, releasing all waiting threads if `count` transitions to zero. If the current `count` is zero, no action occurs and false is returned immediately; otherwise, `count` is decremented by the lesser of `amount` and current `count` i.e. if `amount` is greater than current `count`, then new `count` is zero, else new `count` is current `count` minus `amount`. Parameters amount:int by which to decrement the `count` Returns:boolean `true` if `count` transitions to zero Exceptions IllegalArgumentException: when `amount` is non-positive

public boolean countDown(int amount)

Decrements the count of the latch by the given amount, releasing all waiting threads if count transitions to zero.

If the current count is zero, no action occurs and false is returned immediately; otherwise, count is decremented by the lesser of amount and current count i.e. if amount is greater than current count, then new count is zero, else new count is current count minus amount.

Parameters

amount:int: by which to decrement the count

Returns:boolean

true if count transitions to zero

Exceptions

IllegalArgumentException:: when amount is non-positive

countUp back to summary

countUp	back to summary
public boolean countUp() Increments the count of the latch. Returns:boolean `true` if `count` transitioned from zero to a new value Exceptions ArithmeticException: when the operation would otherwise cause a silent numeric overflow, resulting in a negative `count`.

public boolean countUp()

Increments the count of the latch.

Returns:boolean

true if count transitioned from zero to a new value

Exceptions

ArithmeticException:: when the operation would otherwise cause a silent numeric overflow, resulting in a negative count.

countUp back to summary

countUp	back to summary
public boolean countUp(int amount) Increments the count of the latch by the given `amount`. Parameters amount:int by which to increment `count` Returns:boolean `true` if `count` transitioned from zero to a new value Exceptions ArithmeticException: when the operation would otherwise cause a silent numeric overflow, resulting in a negative `count`. IllegalArgumentException: if `amount` is less than one.

public boolean countUp(int amount)

Increments the count of the latch by the given amount.

Parameters

amount:int: by which to increment count

Returns:boolean

true if count transitioned from zero to a new value

Exceptions

ArithmeticException:: when the operation would otherwise cause a silent numeric overflow, resulting in a negative count.
IllegalArgumentException:: if amount is less than one.

equals back to summary

equals	back to summary
public boolean equals(final CountUpDownLatch other) Returns true if and only if `this` and `obj` refer to the same object (`this == obj` has the value `true`). Parameters other:CountUpDownLatch to test. Returns:boolean if and only if `this == obj`

public boolean equals(final CountUpDownLatch other)

Returns true if and only if this and obj refer to the same object (this == obj has the value true).

Parameters

other:CountUpDownLatch: to test.

Returns:boolean

if and only if this == obj

equals back to summary

equals	back to summary
public boolean equals(Object obj) Overrides java.lang.Object.equals. Returns true if and only if `this` and `obj` refer to the same object (`this == obj` has the value `true`). Parameters obj:Object to test. Returns:boolean if and only if `this == obj`

public boolean equals(Object obj)

Overrides java.lang.Object.equals.

Returns true if and only if this and obj refer to the same object (this == obj has the value true).

Parameters

obj:Object: to test.

Returns:boolean

if and only if this == obj

getCount back to summary

getCount	back to summary
public int getCount() Returns the current count. Because another thread may update `count` at any time, typically this should not be used to compute input values for any of the @{code count} mutating methods and instead should be reserved for debugging and testing purposes (e.g. to assert that the current count is the expected count, given a set of know operations has occurred and given that it is known no other threads could be updating the count) Returns:int the current count

public int getCount()

Returns the current count.

Because another thread may update count at any time, typically this should not be used to compute input values for any of the @{code count} mutating methods and instead should be reserved for debugging and testing purposes (e.g. to assert that the current count is the expected count, given a set of know operations has occurred and given that it is known no other threads could be updating the count)

Returns:int: the current count

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. As much as is reasonably practical, returns distinct integers for distinct objects. Returns:int a hash code value for this latch. This method is supported for the benefit of hash tables

hashCode

back to summary

public int hashCode()

Overrides java.lang.Object.hashCode.

As much as is reasonably practical, returns distinct integers for distinct objects.

Returns:int: a hash code value for this latch. This method is supported for the benefit of hash tables

setCount back to summary

setCount	back to summary
public boolean setCount(int newCount) Updates `count` to the requested `newCount`, returning `true` on transition to zero. If `newCount` is zero and the current `count` is zero, no action occurs and false is returned immediately. immediately; Parameters newCount:int to which to update `count`; must be non-negative. Returns:boolean `true` if `count` transitions to zero. Exceptions IllegalArgumentException: when `newCount` is negative

public boolean setCount(int newCount)

Updates count to the requested newCount, returning true on transition to zero.

If newCount is zero and the current count is zero, no action occurs and false is returned immediately. immediately;

Parameters

newCount:int: to which to update count; must be non-negative.

Returns:boolean

true if count transitions to zero.

Exceptions

IllegalArgumentException:: when newCount is negative

toString back to summary

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Returns a string representation of this object. Returns:String a string identifying this latch, as well as its current `count`.

public String toString()

Overrides java.lang.Object.toString.

Returns a string representation of this object.

Returns:String: a string identifying this latch, as well as its current count.

org.hsqldb.lib back to summary

private Class CountUpDownLatch.Sync

Class Inheritance

extends AbstractQueuedSynchronizer

java.lang.Object
java.util.concurrent.locks.AbstractOwnableSynchronizer
java.util.concurrent.locks.AbstractQueuedSynchronizer
org.hsqldb.lib.CountUpDownLatch.Sync

Synchronization control For CountUpDownLatch.

Uses AbstractQueuedSynchronizer state property to represent count.

Field Summary

Modifier and Type	Field and Description
private static final long	serialVersionUID Hides java.util.concurrent.locks.AbstractQueuedSynchronizer.serialVersionUID.

Constructor Summary

Access	Constructor and Description
pack-priv	Sync(int count)

Method Summary

Modifier and Type	Method and Description
pack-priv boolean	Returns: true if {#code count} transitioned to zero. countDown() by one.
pack-priv boolean	Returns: true if {#code count} transitioned to zero. countDown(int by which to decrement the `count` amount) Counts down by `amount`.
pack-priv boolean	Returns: true if count transitioned to zero countUp() Counts up by one.
pack-priv boolean	Returns: true if count transitioned from zero to a new value countUp(int by which to increment `count` amount) Counts up by `amount`.
pack-priv int	getCount()
pack-priv boolean	Returns: `true` if `count` transitions to zero. setCount(int to which to update `count`; must be non-negative. newCount) Updates `count` to `newCount`, returning `true` on transition to zero.
protected int	Returns: -1 on failure; 1 if acquisition in shared mode succeeded and subsequent shared-mode acquires might also succeed, in which case a subsequent waiting thread must check availability. tryAcquireShared(int ignored param ignored) Overrides java.util.concurrent.locks.AbstractQueuedSynchronizer.tryAcquireShared. Queries if the state of this synchronizer permits it to be acquired in the shared mode, and if so to acquire it.
protected boolean	tryReleaseShared(int arg) Overrides java.util.concurrent.locks.AbstractQueuedSynchronizer.tryReleaseShared. Attempts to set the state to reflect a release in shared mode.

Field Detail

serialVersionUID	back to summary
private static final long serialVersionUID Hides java.util.concurrent.locks.AbstractQueuedSynchronizer.serialVersionUID.

Constructor Detail

Sync	back to summary
pack-priv Sync(int count)

Method Detail

countDown	back to summary
pack-priv boolean countDown() by one. Returns:boolean true if {#code count} transitioned to zero.

countDown

back to summary

pack-priv boolean countDown()

by one.

Returns:boolean: true if {#code count} transitioned to zero.

countDown back to summary

countDown	back to summary
pack-priv boolean countDown(int amount) Counts down by `amount`. Parameters amount:int by which to decrement the `count` Returns:boolean true if {#code count} transitioned to zero. Exceptions IllegalArgumentException: when `amount` is non-positive

pack-priv boolean countDown(int amount)

Counts down by amount.

Parameters

amount:int: by which to decrement the count

Returns:boolean

true if {#code count} transitioned to zero.

Exceptions

IllegalArgumentException:: when amount is non-positive

countUp back to summary

countUp	back to summary
pack-priv boolean countUp() Counts up by one. Returns:boolean true if count transitioned to zero Exceptions ArithmeticException: when the operation would otherwise cause a silent numeric overflow, resulting in a negative `count`.

pack-priv boolean countUp()

Counts up by one.

Returns:boolean

true if count transitioned to zero

Exceptions

ArithmeticException:: when the operation would otherwise cause a silent numeric overflow, resulting in a negative count.

countUp back to summary

countUp	back to summary
pack-priv boolean countUp(int amount) Counts up by `amount`. Parameters amount:int by which to increment `count` Returns:boolean true if count transitioned from zero to a new value Exceptions ArithmeticException: when the operation would otherwise cause a silent numeric overflow, resulting in a negative `count`. IllegalArgumentException: if `amount is less than one`

pack-priv boolean countUp(int amount)

Counts up by amount.

Parameters

amount:int: by which to increment count

Returns:boolean

true if count transitioned from zero to a new value

Exceptions

ArithmeticException:: when the operation would otherwise cause a silent numeric overflow, resulting in a negative count.
IllegalArgumentException:: if amount is less than one

getCount	back to summary
pack-priv int getCount()

setCount back to summary

setCount	back to summary
pack-priv boolean setCount(int newCount) Updates `count` to `newCount`, returning `true` on transition to zero. If `newCount` is zero and the current `count` is zero, no action occurs and false is returned immediately. immediately; Parameters newCount:int to which to update `count`; must be non-negative. Returns:boolean `true` if `count` transitions to zero. Exceptions IllegalArgumentException: when `newCount` is negative

pack-priv boolean setCount(int newCount)

Updates count to newCount, returning true on transition to zero.

If newCount is zero and the current count is zero, no action occurs and false is returned immediately. immediately;

Parameters

newCount:int: to which to update count; must be non-negative.

Returns:boolean

true if count transitions to zero.

Exceptions

IllegalArgumentException:: when newCount is negative

tryAcquireShared back to summary

tryAcquireShared	back to summary
protected int tryAcquireShared(int ignored) Overrides java.util.concurrent.locks.AbstractQueuedSynchronizer.tryAcquireShared. Queries if the state of this synchronizer permits it to be acquired in the shared mode, and if so to acquire it. This implementation supports the required semantics of the `await(...)` methods of the enclosing `CountUpDownLatch` class. Parameters ignored:int ignored param Returns:int -1 on failure; 1 if acquisition in shared mode succeeded and subsequent shared-mode acquires might also succeed, in which case a subsequent waiting thread must check availability.

protected int tryAcquireShared(int ignored)

Overrides java.util.concurrent.locks.AbstractQueuedSynchronizer.tryAcquireShared.

Queries if the state of this synchronizer permits it to be acquired in the shared mode, and if so to acquire it.

This implementation supports the required semantics of the await(...) methods of the enclosing CountUpDownLatch class.

Parameters

ignored:int: ignored param

Returns:int

-1 on failure; 1 if acquisition in shared mode succeeded and subsequent shared-mode acquires might also succeed, in which case a subsequent waiting thread must check availability.

tryReleaseShared back to summary

tryReleaseShared	back to summary
protected boolean tryReleaseShared(int arg) Overrides java.util.concurrent.locks.AbstractQueuedSynchronizer.tryReleaseShared. Doc from java.util.concurrent.locks.AbstractQueuedSynchronizer.tryReleaseShared. Attempts to set the state to reflect a release in shared mode. This method is always invoked by the thread performing release. The default implementation throws `UnsupportedOperationException`.

protected boolean tryReleaseShared(int arg)

Overrides java.util.concurrent.locks.AbstractQueuedSynchronizer.tryReleaseShared.

Doc from java.util.concurrent.locks.AbstractQueuedSynchronizer.tryReleaseShared.

Attempts to set the state to reflect a release in shared mode.

This method is always invoked by the thread performing release.

The default implementation throws UnsupportedOperationException.

public Class CountUpDownLatch

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private Class CountUpDownLatch.Sync

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail