org.apache.cassandra.utils.concurrent

Class AbstractFuture<V>

java.lang.Object

org.apache.cassandra.utils.concurrent.AbstractFuture<V>

All Implemented Interfaces:

com.google.common.util.concurrent.ListenableFuture<V>, java.util.concurrent.Future<V>, Awaitable

Direct Known Subclasses:

AsyncFuture, SyncFuture

public abstract class AbstractFuture<V>
extends java.lang.Object
implements Future<V>

Our default Future implementation, with all state being managed without locks (except those used by the JVM). Some implementation comments versus Netty's default promise: - We permit efficient initial state declaration, avoiding unnecessary CAS or lock acquisitions when mutating a Promise we are ourselves constructing (and can easily add more; only those we use have been added) - We guarantee the order of invocation of listeners (and callbacks etc, and with respect to each other) - We save some space when registering listeners, especially if there is only one listener, as we perform no extra allocations in this case. - We implement our invocation list as a concurrent stack, that is cleared on notification - We handle special values slightly differently. - We do not use a special value for null, instead using a special value to indicate the result has not been set. This means that once isSuccess() holds, the result must be a correctly typed object (modulo generics pitfalls). - All special values are also instances of FailureHolder, which simplifies a number of the logical conditions.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.cassandra.utils.concurrent.Awaitable

Awaitable.AbstractAwaitable, Awaitable.AsyncAwaitable, Awaitable.Defaults, Awaitable.SyncAwaitable

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.apache.cassandra.utils.concurrent.AbstractFuture.FailureHolder	CANCELLED
protected static org.apache.cassandra.utils.concurrent.AbstractFuture.FailureHolder	UNCANCELLABLE
protected static org.apache.cassandra.utils.concurrent.AbstractFuture.FailureHolder	UNSET

Constructor Summary

Constructors

Modifier	Constructor and Description
	AbstractFuture()
protected	AbstractFuture(org.apache.cassandra.utils.concurrent.AbstractFuture.FailureHolder initialState)
protected	AbstractFuture(org.apache.cassandra.utils.concurrent.AbstractFuture.FailureHolder initialState, io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>> listener)
protected	AbstractFuture(io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>> listener)
protected	AbstractFuture(java.lang.Throwable immediateFailure)
protected	AbstractFuture(V immediateSuccess)

Method Summary

Modifier and Type	Method and Description
AbstractFuture<V>	addCallback(java.util.function.BiConsumer<? super V,java.lang.Throwable> callback) Support Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) natively See addListener(GenericFutureListener) for ordering semantics.
Future<V>	addCallback(java.util.function.BiConsumer<? super V,java.lang.Throwable> callback, java.util.concurrent.Executor executor) Support Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) natively
AbstractFuture<V>	addCallback(java.util.function.Consumer<? super V> onSuccess, java.util.function.Consumer<? super java.lang.Throwable> onFailure) Support more fluid version of Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) See addListener(GenericFutureListener) for ordering semantics.
AbstractFuture<V>	addCallback(java.util.function.Consumer<? super V> onSuccess, java.util.function.Consumer<? super java.lang.Throwable> onFailure, java.util.concurrent.Executor executor) Support more fluid version of Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) See addListener(GenericFutureListener) for ordering semantics.
AbstractFuture<V>	addCallback(com.google.common.util.concurrent.FutureCallback<? super V> callback) Support Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) natively See addListener(GenericFutureListener) for ordering semantics.
AbstractFuture<V>	addCallback(com.google.common.util.concurrent.FutureCallback<? super V> callback, java.util.concurrent.Executor executor) Support Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) natively See addListener(GenericFutureListener) for ordering semantics.
Future<V>	addListener(io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>> listener) Add a listener to be invoked once this future completes.
void	addListener(java.lang.Runnable task) Add a listener to be invoked once this future completes.
void	addListener(java.lang.Runnable task, java.util.concurrent.Executor executor) Add a listener to be invoked once this future completes.
Future<V>	addListeners(io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>>... listeners)
boolean	await(long timeout, java.util.concurrent.TimeUnit unit) Await for the specified period, throwing any interrupt.
Future<V>	awaitThrowUncheckedOnInterrupt() Wait for this future to complete Awaitable.awaitThrowUncheckedOnInterrupt()
boolean	awaitThrowUncheckedOnInterrupt(long time, java.util.concurrent.TimeUnit units) Await for the specified period, throwing any interrupt as an unchecked exception.
Future<V>	awaitUninterruptibly() Wait for this future to complete Awaitable.awaitUninterruptibly()
boolean	awaitUninterruptibly(long timeout, java.util.concurrent.TimeUnit unit) Await until the deadline (in nanoTime), ignoring interrupts (but maintaining the interrupt flag on exit).
boolean	awaitUntilThrowUncheckedOnInterrupt(long nanoTimeDeadline) Await until the deadline (in nanoTime), throwing any interrupt as an unchecked exception.
boolean	awaitUntilUninterruptibly(long nanoTimeDeadline) Await until the deadline (in nanoTime), ignoring interrupts (but maintaining the interrupt flag on exit).
boolean	cancel(boolean b)
java.lang.Throwable	cause()
protected java.lang.String	description()
protected <T> Future<T>	flatMap(AbstractFuture<T> result, java.util.function.Function<? super V,? extends Future<T>> flatMapper, java.util.concurrent.Executor executor) Support Futures.transformAsync(ListenableFuture, AsyncFunction, Executor) natively See addListener(GenericFutureListener) for ordering semantics.
V	get()
V	get(long timeout, java.util.concurrent.TimeUnit unit)
V	getNow() if isSuccess(), returns the value, otherwise returns null
protected V	getWhenDone() Shared implementation of get() after suitable await(); assumes isDone(), and returns either the success result or throws the suitable exception under failure
boolean	isCancellable()
boolean	isCancelled()
boolean	isDone()
boolean	isSuccess()
protected boolean	isUncancellable()
protected <T> Future<T>	map(AbstractFuture<T> result, java.util.function.Function<? super V,? extends T> mapper, java.util.concurrent.Executor executor) Support Futures.transform(ListenableFuture, com.google.common.base.Function, Executor) natively See addListener(GenericFutureListener) for ordering semantics.
<T> Future<T>	map(java.util.function.Function<? super V,? extends T> mapper) Support Futures.transformAsync(ListenableFuture, AsyncFunction, Executor) natively See addListener(GenericFutureListener) for ordering semantics.
java.util.concurrent.Executor	notifyExecutor()
Future<V>	removeListener(io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>> listener)
Future<V>	removeListeners(io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>>... listeners)
protected boolean	setUncancellable()
protected boolean	setUncancellableExclusive()
java.lang.String	toString()
protected boolean	tryFailure(java.lang.Throwable throwable)
protected boolean	trySuccess(V v)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.cassandra.utils.concurrent.Future

await, await, awaitUninterruptibly, flatMap, flatMap, map, rethrowIfFailed, sync, syncThrowUncheckedOnInterrupt, syncUninterruptibly

Methods inherited from interface org.apache.cassandra.utils.concurrent.Awaitable

awaitUntil

Field Detail

UNSET

protected static final org.apache.cassandra.utils.concurrent.AbstractFuture.FailureHolder UNSET

UNCANCELLABLE

protected static final org.apache.cassandra.utils.concurrent.AbstractFuture.FailureHolder UNCANCELLABLE

CANCELLED

protected static final org.apache.cassandra.utils.concurrent.AbstractFuture.FailureHolder CANCELLED

Constructor Detail

AbstractFuture

protected AbstractFuture(org.apache.cassandra.utils.concurrent.AbstractFuture.FailureHolder initialState)

AbstractFuture

public AbstractFuture()

AbstractFuture

protected AbstractFuture(V immediateSuccess)

AbstractFuture

protected AbstractFuture(java.lang.Throwable immediateFailure)

AbstractFuture

protected AbstractFuture(io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>> listener)

AbstractFuture

protected AbstractFuture(org.apache.cassandra.utils.concurrent.AbstractFuture.FailureHolder initialState,
                         io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>> listener)

Method Detail

notifyExecutor

public java.util.concurrent.Executor notifyExecutor()

trySuccess

protected boolean trySuccess(V v)

tryFailure

protected boolean tryFailure(java.lang.Throwable throwable)

setUncancellable

protected boolean setUncancellable()

setUncancellableExclusive

protected boolean setUncancellableExclusive()

isUncancellable

protected boolean isUncancellable()

cancel

public boolean cancel(boolean b)

Specified by:

cancel in interface java.util.concurrent.Future<V>

isSuccess

public boolean isSuccess()

isCancelled

public boolean isCancelled()

Specified by:

isCancelled in interface java.util.concurrent.Future<V>

isDone

public boolean isDone()

Specified by:

isDone in interface java.util.concurrent.Future<V>

isCancellable

public boolean isCancellable()

cause

public java.lang.Throwable cause()

getNow

public V getNow()

if isSuccess(), returns the value, otherwise returns null

getWhenDone

protected V getWhenDone()
                 throws java.util.concurrent.ExecutionException

Shared implementation of get() after suitable await(); assumes isDone(), and returns either the success result or throws the suitable exception under failure

Throws:

java.util.concurrent.ExecutionException

get

public V get()
      throws java.lang.InterruptedException,
             java.util.concurrent.ExecutionException

Specified by:

get in interface java.util.concurrent.Future<V>

Throws:

java.lang.InterruptedException

java.util.concurrent.ExecutionException

get

public V get(long timeout,
             java.util.concurrent.TimeUnit unit)
      throws java.lang.InterruptedException,
             java.util.concurrent.ExecutionException,
             java.util.concurrent.TimeoutException

Specified by:

get in interface java.util.concurrent.Future<V>

Throws:

java.lang.InterruptedException

java.util.concurrent.ExecutionException

java.util.concurrent.TimeoutException

addCallback

public AbstractFuture<V> addCallback(com.google.common.util.concurrent.FutureCallback<? super V> callback)

Support Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) natively See addListener(GenericFutureListener) for ordering semantics.

addCallback

public AbstractFuture<V> addCallback(java.util.function.BiConsumer<? super V,java.lang.Throwable> callback)

Support Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) natively See addListener(GenericFutureListener) for ordering semantics.

addCallback

public Future<V> addCallback(java.util.function.BiConsumer<? super V,java.lang.Throwable> callback,
                             java.util.concurrent.Executor executor)

Description copied from interface: Future

Support Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) natively

addCallback

public AbstractFuture<V> addCallback(com.google.common.util.concurrent.FutureCallback<? super V> callback,
                                     java.util.concurrent.Executor executor)

Support Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) natively See addListener(GenericFutureListener) for ordering semantics.

addCallback

public AbstractFuture<V> addCallback(java.util.function.Consumer<? super V> onSuccess,
                                     java.util.function.Consumer<? super java.lang.Throwable> onFailure)

Support more fluid version of Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) See addListener(GenericFutureListener) for ordering semantics.

map

public <T> Future<T> map(java.util.function.Function<? super V,? extends T> mapper)

Support Futures.transformAsync(ListenableFuture, AsyncFunction, Executor) natively See addListener(GenericFutureListener) for ordering semantics.

addCallback

public AbstractFuture<V> addCallback(java.util.function.Consumer<? super V> onSuccess,
                                     java.util.function.Consumer<? super java.lang.Throwable> onFailure,
                                     java.util.concurrent.Executor executor)

Support more fluid version of Futures.addCallback(com.google.common.util.concurrent.ListenableFuture<V>, com.google.common.util.concurrent.FutureCallback<? super V>, java.util.concurrent.Executor) See addListener(GenericFutureListener) for ordering semantics.

map

protected <T> Future<T> map(AbstractFuture<T> result,
                            java.util.function.Function<? super V,? extends T> mapper,
                            @Nullable
                            java.util.concurrent.Executor executor)

Support Futures.transform(ListenableFuture, com.google.common.base.Function, Executor) natively See addListener(GenericFutureListener) for ordering semantics.

flatMap

protected <T> Future<T> flatMap(AbstractFuture<T> result,
                                java.util.function.Function<? super V,? extends Future<T>> flatMapper,
                                @Nullable
                                java.util.concurrent.Executor executor)

Support Futures.transformAsync(ListenableFuture, AsyncFunction, Executor) natively See addListener(GenericFutureListener) for ordering semantics.

addListener

public Future<V> addListener(io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>> listener)

Add a listener to be invoked once this future completes. Listeners are submitted to notifyExecutor() in the order they are added (or the specified executor in the case of addListener(Runnable, Executor). if notifyExecutor() is unset, they are invoked in the order they are added. The ordering holds across all variants of this method.

addListener

public void addListener(java.lang.Runnable task,
                        @Nullable
                        java.util.concurrent.Executor executor)

Add a listener to be invoked once this future completes. Listeners are submitted to their #executor (or notifyExecutor()) in the order they are added; if notifyExecutor() is unset, they are invoked in the order they are added. The ordering holds across all variants of this method.

Specified by:

addListener in interface com.google.common.util.concurrent.ListenableFuture<V>

addListener

public void addListener(java.lang.Runnable task)

Add a listener to be invoked once this future completes. Listeners are submitted to notifyExecutor() in the order they are added (or the specified executor in the case of addListener(Runnable, Executor). if notifyExecutor() is unset, they are invoked in the order they are added. The ordering holds across all variants of this method.

addListeners

public Future<V> addListeners(io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>>... listeners)

removeListener

public Future<V> removeListener(io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>> listener)

removeListeners

public Future<V> removeListeners(io.netty.util.concurrent.GenericFutureListener<? extends io.netty.util.concurrent.Future<? super V>>... listeners)

await

public boolean await(long timeout,
                     java.util.concurrent.TimeUnit unit)
              throws java.lang.InterruptedException

Description copied from interface: Awaitable

Await for the specified period, throwing any interrupt. No spurious wakeups.

Specified by:

await in interface Awaitable

Returns:

true if we were signalled, false if the timeout elapses

Throws:

java.lang.InterruptedException - if interrupted

awaitThrowUncheckedOnInterrupt

public boolean awaitThrowUncheckedOnInterrupt(long time,
                                              java.util.concurrent.TimeUnit units)
                                       throws UncheckedInterruptedException

Description copied from interface: Awaitable

Await for the specified period, throwing any interrupt as an unchecked exception. No spurious wakeups.

Specified by:

awaitThrowUncheckedOnInterrupt in interface Awaitable

Returns:

true if we were signalled, false if the timeout elapses

Throws:

UncheckedInterruptedException - if interrupted

awaitUninterruptibly

public boolean awaitUninterruptibly(long timeout,
                                    java.util.concurrent.TimeUnit unit)

Description copied from interface: Awaitable

Await until the deadline (in nanoTime), ignoring interrupts (but maintaining the interrupt flag on exit). No spurious wakeups.

Specified by:

awaitUninterruptibly in interface Awaitable

Returns:

true if we were signalled, false if the timeout elapses

awaitUntilThrowUncheckedOnInterrupt

public boolean awaitUntilThrowUncheckedOnInterrupt(long nanoTimeDeadline)
                                            throws UncheckedInterruptedException

Description copied from interface: Awaitable

Await until the deadline (in nanoTime), throwing any interrupt as an unchecked exception. No spurious wakeups.

Specified by:

awaitUntilThrowUncheckedOnInterrupt in interface Awaitable

Returns:

true if we were signalled, false if the deadline elapsed

Throws:

UncheckedInterruptedException - if interrupted

awaitUntilUninterruptibly

public boolean awaitUntilUninterruptibly(long nanoTimeDeadline)

Description copied from interface: Awaitable

Await until the deadline (in nanoTime), ignoring interrupts (but maintaining the interrupt flag on exit). No spurious wakeups.

Specified by:

awaitUntilUninterruptibly in interface Awaitable

Returns:

true if we were signalled, false if the deadline elapsed

awaitUninterruptibly

public Future<V> awaitUninterruptibly()

Wait for this future to complete Awaitable.awaitUninterruptibly()

Specified by:

awaitUninterruptibly in interface Awaitable

awaitThrowUncheckedOnInterrupt

public Future<V> awaitThrowUncheckedOnInterrupt()
                                         throws UncheckedInterruptedException

Wait for this future to complete Awaitable.awaitThrowUncheckedOnInterrupt()

Specified by:

awaitThrowUncheckedOnInterrupt in interface Awaitable

Throws:

UncheckedInterruptedException - if interrupted

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

description

protected java.lang.String description()