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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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*/ |
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|
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package java.util.concurrent; |
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|
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import java.lang.invoke.MethodHandles; |
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import java.lang.invoke.VarHandle; |
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import java.util.concurrent.locks.LockSupport; |
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import java.util.function.BiConsumer; |
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import java.util.function.BiFunction; |
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import java.util.function.Consumer; |
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import java.util.function.Function; |
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import java.util.function.Supplier; |
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|
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/** |
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* A {@link Future} that may be explicitly completed (setting its |
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* value and status), and may be used as a {@link CompletionStage}, |
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* supporting dependent functions and actions that trigger upon its |
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* completion. |
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* |
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* <p>When two or more threads attempt to |
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* {@link #complete complete}, |
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* {@link #completeExceptionally completeExceptionally}, or |
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* {@link #cancel cancel} |
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* a CompletableFuture, only one of them succeeds. |
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* |
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* <p>In addition to these and related methods for directly |
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* manipulating status and results, CompletableFuture implements |
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* interface {@link CompletionStage} with the following policies: <ul> |
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* |
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* <li>Actions supplied for dependent completions of |
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* <em>non-async</em> methods may be performed by the thread that |
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* completes the current CompletableFuture, or by any other caller of |
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* a completion method. |
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* |
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* <li>All <em>async</em> methods without an explicit Executor |
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* argument are performed using the {@link ForkJoinPool#commonPool()} |
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* (unless it does not support a parallelism level of at least two, in |
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* which case, a new Thread is created to run each task). This may be |
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* overridden for non-static methods in subclasses by defining method |
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* {@link #defaultExecutor()}. To simplify monitoring, debugging, |
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* and tracking, all generated asynchronous tasks are instances of the |
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* marker interface {@link AsynchronousCompletionTask}. Operations |
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* with time-delays can use adapter methods defined in this class, for |
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* example: {@code supplyAsync(supplier, delayedExecutor(timeout, |
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* timeUnit))}. To support methods with delays and timeouts, this |
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* class maintains at most one daemon thread for triggering and |
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* cancelling actions, not for running them. |
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* |
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* <li>All CompletionStage methods are implemented independently of |
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* other public methods, so the behavior of one method is not impacted |
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* by overrides of others in subclasses. |
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* |
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* <li>All CompletionStage methods return CompletableFutures. To |
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* restrict usages to only those methods defined in interface |
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* CompletionStage, use method {@link #minimalCompletionStage}. Or to |
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* ensure only that clients do not themselves modify a future, use |
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* method {@link #copy}. |
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* </ul> |
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* |
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* <p>CompletableFuture also implements {@link Future} with the following |
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* policies: <ul> |
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* |
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* <li>Since (unlike {@link FutureTask}) this class has no direct |
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* control over the computation that causes it to be completed, |
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* cancellation is treated as just another form of exceptional |
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* completion. Method {@link #cancel cancel} has the same effect as |
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* {@code completeExceptionally(new CancellationException())}. Method |
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* {@link #isCompletedExceptionally} can be used to determine if a |
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* CompletableFuture completed in any exceptional fashion. |
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* |
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* <li>In case of exceptional completion with a CompletionException, |
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* methods {@link #get()} and {@link #get(long, TimeUnit)} throw an |
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* {@link ExecutionException} with the same cause as held in the |
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* corresponding CompletionException. To simplify usage in most |
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* contexts, this class also defines methods {@link #join()} and |
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* {@link #getNow} that instead throw the CompletionException directly |
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* in these cases. |
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* </ul> |
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* |
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* <p>Arguments used to pass a completion result (that is, for |
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* parameters of type {@code T}) for methods accepting them may be |
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* null, but passing a null value for any other parameter will result |
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* in a {@link NullPointerException} being thrown. |
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* |
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* <p>Subclasses of this class should normally override the "virtual |
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* constructor" method {@link #newIncompleteFuture}, which establishes |
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* the concrete type returned by CompletionStage methods. For example, |
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* here is a class that substitutes a different default Executor and |
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* disables the {@code obtrude} methods: |
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* |
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* <pre> {@code |
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* class MyCompletableFuture<T> extends CompletableFuture<T> { |
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* static final Executor myExecutor = ...; |
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* public MyCompletableFuture() { } |
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* public <U> CompletableFuture<U> newIncompleteFuture() { |
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* return new MyCompletableFuture<U>(); } |
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* public Executor defaultExecutor() { |
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* return myExecutor; } |
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* public void obtrudeValue(T value) { |
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* throw new UnsupportedOperationException(); } |
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* public void obtrudeException(Throwable ex) { |
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* throw new UnsupportedOperationException(); } |
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* }}</pre> |
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* |
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* @author Doug Lea |
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* @since 1.8 |
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* @param <T> The result type returned by this future's {@code join} |
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* and {@code get} methods |
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*/ |
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public class CompletableFuture<T> implements Future<T>, CompletionStage<T> { |
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|
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/* |
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* Overview: |
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* |
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* A CompletableFuture may have dependent completion actions, |
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* collected in a linked stack. It atomically completes by CASing |
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* a result field, and then pops off and runs those actions. This |
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* applies across normal vs exceptional outcomes, sync vs async |
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* actions, binary triggers, and various forms of completions. |
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* |
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* Non-nullness of volatile field "result" indicates done. It may |
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* be set directly if known to be thread-confined, else via CAS. |
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* An AltResult is used to box null as a result, as well as to |
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* hold exceptions. Using a single field makes completion simple |
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* to detect and trigger. Result encoding and decoding is |
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* straightforward but tedious and adds to the sprawl of trapping |
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* and associating exceptions with targets. Minor simplifications |
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* rely on (static) NIL (to box null results) being the only |
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* AltResult with a null exception field, so we don't usually need |
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* explicit comparisons. Even though some of the generics casts |
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* are unchecked (see SuppressWarnings annotations), they are |
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* placed to be appropriate even if checked. |
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* |
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* Dependent actions are represented by Completion objects linked |
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* as Treiber stacks headed by field "stack". There are Completion |
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* classes for each kind of action, grouped into: |
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* - single-input (UniCompletion), |
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* - two-input (BiCompletion), |
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* - projected (BiCompletions using exactly one of two inputs), |
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* - shared (CoCompletion, used by the second of two sources), |
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* - zero-input source actions, |
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* - Signallers that unblock waiters. |
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* Class Completion extends ForkJoinTask to enable async execution |
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* (adding no space overhead because we exploit its "tag" methods |
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* to maintain claims). It is also declared as Runnable to allow |
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* usage with arbitrary executors. |
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* |
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* Support for each kind of CompletionStage relies on a separate |
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* class, along with two CompletableFuture methods: |
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* |
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* * A Completion class with name X corresponding to function, |
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* prefaced with "Uni", "Bi", or "Or". Each class contains |
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* fields for source(s), actions, and dependent. They are |
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* boringly similar, differing from others only with respect to |
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* underlying functional forms. We do this so that users don't |
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* encounter layers of adapters in common usages. |
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* |
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* * Boolean CompletableFuture method x(...) (for example |
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* biApply) takes all of the arguments needed to check that an |
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* action is triggerable, and then either runs the action or |
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* arranges its async execution by executing its Completion |
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* argument, if present. The method returns true if known to be |
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* complete. |
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* |
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* * Completion method tryFire(int mode) invokes the associated x |
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* method with its held arguments, and on success cleans up. |
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* The mode argument allows tryFire to be called twice (SYNC, |
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* then ASYNC); the first to screen and trap exceptions while |
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* arranging to execute, and the second when called from a task. |
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* (A few classes are not used async so take slightly different |
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* forms.) The claim() callback suppresses function invocation |
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* if already claimed by another thread. |
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* |
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* * Some classes (for example UniApply) have separate handling |
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* code for when known to be thread-confined ("now" methods) and |
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* for when shared (in tryFire), for efficiency. |
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* |
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* * CompletableFuture method xStage(...) is called from a public |
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* stage method of CompletableFuture f. It screens user |
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* arguments and invokes and/or creates the stage object. If |
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* not async and already triggerable, the action is run |
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* immediately. Otherwise a Completion c is created, and |
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* submitted to the executor if triggerable, or pushed onto f's |
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* stack if not. Completion actions are started via c.tryFire. |
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* We recheck after pushing to a source future's stack to cover |
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* possible races if the source completes while pushing. |
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* Classes with two inputs (for example BiApply) deal with races |
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* across both while pushing actions. The second completion is |
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* a CoCompletion pointing to the first, shared so that at most |
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* one performs the action. The multiple-arity methods allOf |
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* and anyOf do this pairwise to form trees of completions. |
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* |
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* Note that the generic type parameters of methods vary according |
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* to whether "this" is a source, dependent, or completion. |
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* |
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* Method postComplete is called upon completion unless the target |
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* is guaranteed not to be observable (i.e., not yet returned or |
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* linked). Multiple threads can call postComplete, which |
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* atomically pops each dependent action, and tries to trigger it |
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* via method tryFire, in NESTED mode. Triggering can propagate |
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* recursively, so NESTED mode returns its completed dependent (if |
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* one exists) for further processing by its caller (see method |
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* postFire). |
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* |
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* Blocking methods get() and join() rely on Signaller Completions |
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* that wake up waiting threads. The mechanics are similar to |
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* Treiber stack wait-nodes used in FutureTask, Phaser, and |
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* SynchronousQueue. See their internal documentation for |
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* algorithmic details. |
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* |
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* Without precautions, CompletableFutures would be prone to |
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* garbage accumulation as chains of Completions build up, each |
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* pointing back to its sources. So we null out fields as soon as |
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* possible. The screening checks needed anyway harmlessly ignore |
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* null arguments that may have been obtained during races with |
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* threads nulling out fields. We also try to unlink non-isLive |
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* (fired or cancelled) Completions from stacks that might |
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* otherwise never be popped: Method cleanStack always unlinks non |
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* isLive completions from the head of stack; others may |
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* occasionally remain if racing with other cancellations or |
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* removals. |
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* |
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* Completion fields need not be declared as final or volatile |
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* because they are only visible to other threads upon safe |
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* publication. |
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*/ |
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|
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volatile Object result; // Either the result or boxed AltResult |
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volatile Completion stack; // Top of Treiber stack of dependent actions |
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|
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final boolean internalComplete(Object r) { // CAS from null to r |
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return RESULT.compareAndSet(this, null, r); |
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} |
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|
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/** Returns true if successfully pushed c onto stack. */ |
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final boolean tryPushStack(Completion c) { |
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Completion h = stack; |
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NEXT.set(c, h); // CAS piggyback |
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return STACK.compareAndSet(this, h, c); |
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} |
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|
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/** Unconditionally pushes c onto stack, retrying if necessary. */ |
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final void pushStack(Completion c) { |
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do {} while (!tryPushStack(c)); |
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} |
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|
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/* ------------- Encoding and decoding outcomes -------------- */ |
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|
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static final class AltResult { // See above |
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final Throwable ex; // null only for NIL |
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AltResult(Throwable x) { this.ex = x; } |
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} |
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|
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/** The encoding of the null value. */ |
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static final AltResult NIL = new AltResult(null); |
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|
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/** Completes with the null value, unless already completed. */ |
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final boolean completeNull() { |
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return RESULT.compareAndSet(this, null, NIL); |
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} |
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|
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/** Returns the encoding of the given non-exceptional value. */ |
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final Object encodeValue(T t) { |
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return (t == null) ? NIL : t; |
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} |
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|
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/** Completes with a non-exceptional result, unless already completed. */ |
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final boolean completeValue(T t) { |
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return RESULT.compareAndSet(this, null, (t == null) ? NIL : t); |
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} |
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|
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/** |
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* Returns the encoding of the given (non-null) exception as a |
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* wrapped CompletionException unless it is one already. |
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*/ |
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static AltResult encodeThrowable(Throwable x) { |
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return new AltResult((x instanceof CompletionException) ? x : |
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new CompletionException(x)); |
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} |
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|
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/** Completes with an exceptional result, unless already completed. */ |
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final boolean completeThrowable(Throwable x) { |
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return RESULT.compareAndSet(this, null, encodeThrowable(x)); |
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} |
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|
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/** |
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* Returns the encoding of the given (non-null) exception as a |
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* wrapped CompletionException unless it is one already. May |
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* return the given Object r (which must have been the result of a |
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* source future) if it is equivalent, i.e. if this is a simple |
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* relay of an existing CompletionException. |
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*/ |
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static Object encodeThrowable(Throwable x, Object r) { |
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if (!(x instanceof CompletionException)) |
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x = new CompletionException(x); |
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else if (r instanceof AltResult && x == ((AltResult)r).ex) |
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return r; |
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return new AltResult(x); |
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} |
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|
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/** |
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* Completes with the given (non-null) exceptional result as a |
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* wrapped CompletionException unless it is one already, unless |
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* already completed. May complete with the given Object r |
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* (which must have been the result of a source future) if it is |
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* equivalent, i.e. if this is a simple propagation of an |
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* existing CompletionException. |
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*/ |
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final boolean completeThrowable(Throwable x, Object r) { |
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return RESULT.compareAndSet(this, null, encodeThrowable(x, r)); |
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} |
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|
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/** |
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* Returns the encoding of the given arguments: if the exception |
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* is non-null, encodes as AltResult. Otherwise uses the given |
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* value, boxed as NIL if null. |
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*/ |
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Object encodeOutcome(T t, Throwable x) { |
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return (x == null) ? (t == null) ? NIL : t : encodeThrowable(x); |
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} |
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|
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/** |
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* Returns the encoding of a copied outcome; if exceptional, |
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* rewraps as a CompletionException, else returns argument. |
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*/ |
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static Object encodeRelay(Object r) { |
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Throwable x; |
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if (r instanceof AltResult |
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&& (x = ((AltResult)r).ex) != null |
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&& !(x instanceof CompletionException)) |
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r = new AltResult(new CompletionException(x)); |
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return r; |
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} |
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|
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/** |
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* Completes with r or a copy of r, unless already completed. |
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* If exceptional, r is first coerced to a CompletionException. |
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*/ |
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final boolean completeRelay(Object r) { |
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return RESULT.compareAndSet(this, null, encodeRelay(r)); |
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} |
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|
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/** |
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* Reports result using Future.get conventions. |
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*/ |
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private static Object reportGet(Object r) |
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throws InterruptedException, ExecutionException { |
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if (r == null) // by convention below, null means interrupted |
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throw new InterruptedException(); |
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if (r instanceof AltResult) { |
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Throwable x, cause; |
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if ((x = ((AltResult)r).ex) == null) |
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return null; |
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if (x instanceof CancellationException) |
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throw (CancellationException)x; |
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if ((x instanceof CompletionException) && |
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(cause = x.getCause()) != null) |
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x = cause; |
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throw new ExecutionException(x); |
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} |
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return r; |
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} |
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|
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/** |
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* Decodes outcome to return result or throw unchecked exception. |
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*/ |
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private static Object reportJoin(Object r) { |
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if (r instanceof AltResult) { |
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Throwable x; |
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if ((x = ((AltResult)r).ex) == null) |
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return null; |
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if (x instanceof CancellationException) |
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throw (CancellationException)x; |
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if (x instanceof CompletionException) |
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throw (CompletionException)x; |
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throw new CompletionException(x); |
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} |
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return r; |
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} |
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|
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/* ------------- Async task preliminaries -------------- */ |
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|
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/** |
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* A marker interface identifying asynchronous tasks produced by |
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* {@code async} methods. This may be useful for monitoring, |
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* debugging, and tracking asynchronous activities. |
391 |
* |
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* @since 1.8 |
393 |
*/ |
394 |
public static interface AsynchronousCompletionTask { |
395 |
} |
396 |
|
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private static final boolean USE_COMMON_POOL = |
398 |
(ForkJoinPool.getCommonPoolParallelism() > 1); |
399 |
|
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/** |
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* Default executor -- ForkJoinPool.commonPool() unless it cannot |
402 |
* support parallelism. |
403 |
*/ |
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private static final Executor ASYNC_POOL = USE_COMMON_POOL ? |
405 |
ForkJoinPool.commonPool() : new ThreadPerTaskExecutor(); |
406 |
|
407 |
/** Fallback if ForkJoinPool.commonPool() cannot support parallelism */ |
408 |
static final class ThreadPerTaskExecutor implements Executor { |
409 |
public void execute(Runnable r) { new Thread(r).start(); } |
410 |
} |
411 |
|
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/** |
413 |
* Null-checks user executor argument, and translates uses of |
414 |
* commonPool to ASYNC_POOL in case parallelism disabled. |
415 |
*/ |
416 |
static Executor screenExecutor(Executor e) { |
417 |
if (!USE_COMMON_POOL && e == ForkJoinPool.commonPool()) |
418 |
return ASYNC_POOL; |
419 |
if (e == null) throw new NullPointerException(); |
420 |
return e; |
421 |
} |
422 |
|
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// Modes for Completion.tryFire. Signedness matters. |
424 |
static final int SYNC = 0; |
425 |
static final int ASYNC = 1; |
426 |
static final int NESTED = -1; |
427 |
|
428 |
/* ------------- Base Completion classes and operations -------------- */ |
429 |
|
430 |
@SuppressWarnings("serial") |
431 |
abstract static class Completion extends ForkJoinTask<Void> |
432 |
implements Runnable, AsynchronousCompletionTask { |
433 |
volatile Completion next; // Treiber stack link |
434 |
|
435 |
/** |
436 |
* Performs completion action if triggered, returning a |
437 |
* dependent that may need propagation, if one exists. |
438 |
* |
439 |
* @param mode SYNC, ASYNC, or NESTED |
440 |
*/ |
441 |
abstract CompletableFuture<?> tryFire(int mode); |
442 |
|
443 |
/** Returns true if possibly still triggerable. Used by cleanStack. */ |
444 |
abstract boolean isLive(); |
445 |
|
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public final void run() { tryFire(ASYNC); } |
447 |
public final boolean exec() { tryFire(ASYNC); return false; } |
448 |
public final Void getRawResult() { return null; } |
449 |
public final void setRawResult(Void v) {} |
450 |
} |
451 |
|
452 |
/** |
453 |
* Pops and tries to trigger all reachable dependents. Call only |
454 |
* when known to be done. |
455 |
*/ |
456 |
final void postComplete() { |
457 |
/* |
458 |
* On each step, variable f holds current dependents to pop |
459 |
* and run. It is extended along only one path at a time, |
460 |
* pushing others to avoid unbounded recursion. |
461 |
*/ |
462 |
CompletableFuture<?> f = this; Completion h; |
463 |
while ((h = f.stack) != null || |
464 |
(f != this && (h = (f = this).stack) != null)) { |
465 |
CompletableFuture<?> d; Completion t; |
466 |
if (STACK.compareAndSet(f, h, t = h.next)) { |
467 |
if (t != null) { |
468 |
if (f != this) { |
469 |
pushStack(h); |
470 |
continue; |
471 |
} |
472 |
NEXT.compareAndSet(h, t, null); // try to detach |
473 |
} |
474 |
f = (d = h.tryFire(NESTED)) == null ? this : d; |
475 |
} |
476 |
} |
477 |
} |
478 |
|
479 |
/** Traverses stack and unlinks one or more dead Completions, if found. */ |
480 |
final void cleanStack() { |
481 |
boolean unlinked = false; |
482 |
Completion p; |
483 |
while ((p = stack) != null && !p.isLive()) // ensure head of stack live |
484 |
unlinked = STACK.compareAndSet(this, p, p.next); |
485 |
if (p != null && !unlinked) { // try to unlink first nonlive |
486 |
for (Completion q = p.next; q != null;) { |
487 |
Completion s = q.next; |
488 |
if (q.isLive()) { |
489 |
p = q; |
490 |
q = s; |
491 |
} |
492 |
else { |
493 |
NEXT.compareAndSet(p, q, s); |
494 |
break; |
495 |
} |
496 |
} |
497 |
} |
498 |
} |
499 |
|
500 |
/* ------------- One-input Completions -------------- */ |
501 |
|
502 |
/** A Completion with a source, dependent, and executor. */ |
503 |
@SuppressWarnings("serial") |
504 |
abstract static class UniCompletion<T,V> extends Completion { |
505 |
Executor executor; // executor to use (null if none) |
506 |
CompletableFuture<V> dep; // the dependent to complete |
507 |
CompletableFuture<T> src; // source for action |
508 |
|
509 |
UniCompletion(Executor executor, CompletableFuture<V> dep, |
510 |
CompletableFuture<T> src) { |
511 |
this.executor = executor; this.dep = dep; this.src = src; |
512 |
} |
513 |
|
514 |
/** |
515 |
* Returns true if action can be run. Call only when known to |
516 |
* be triggerable. Uses FJ tag bit to ensure that only one |
517 |
* thread claims ownership. If async, starts as task -- a |
518 |
* later call to tryFire will run action. |
519 |
*/ |
520 |
final boolean claim() { |
521 |
Executor e = executor; |
522 |
if (compareAndSetForkJoinTaskTag((short)0, (short)1)) { |
523 |
if (e == null) |
524 |
return true; |
525 |
executor = null; // disable |
526 |
e.execute(this); |
527 |
} |
528 |
return false; |
529 |
} |
530 |
|
531 |
final boolean isLive() { return dep != null; } |
532 |
} |
533 |
|
534 |
/** |
535 |
* Pushes the given completion unless it completes while trying. |
536 |
* Caller should first check that result is null. |
537 |
*/ |
538 |
final void unipush(Completion c) { |
539 |
if (c != null) { |
540 |
while (!tryPushStack(c)) { |
541 |
if (result != null) { |
542 |
NEXT.set(c, null); |
543 |
break; |
544 |
} |
545 |
} |
546 |
if (result != null) |
547 |
c.tryFire(SYNC); |
548 |
} |
549 |
} |
550 |
|
551 |
/** |
552 |
* Post-processing by dependent after successful UniCompletion |
553 |
* tryFire. Tries to clean stack of source a, and then either runs |
554 |
* postComplete or returns this to caller, depending on mode. |
555 |
*/ |
556 |
final CompletableFuture<T> postFire(CompletableFuture<?> a, int mode) { |
557 |
if (a != null && a.stack != null) { |
558 |
Object r; |
559 |
if ((r = a.result) == null) |
560 |
a.cleanStack(); |
561 |
if (mode >= 0 && (r != null || a.result != null)) |
562 |
a.postComplete(); |
563 |
} |
564 |
if (result != null && stack != null) { |
565 |
if (mode < 0) |
566 |
return this; |
567 |
else |
568 |
postComplete(); |
569 |
} |
570 |
return null; |
571 |
} |
572 |
|
573 |
@SuppressWarnings("serial") |
574 |
static final class UniApply<T,V> extends UniCompletion<T,V> { |
575 |
Function<? super T,? extends V> fn; |
576 |
UniApply(Executor executor, CompletableFuture<V> dep, |
577 |
CompletableFuture<T> src, |
578 |
Function<? super T,? extends V> fn) { |
579 |
super(executor, dep, src); this.fn = fn; |
580 |
} |
581 |
final CompletableFuture<V> tryFire(int mode) { |
582 |
CompletableFuture<V> d; CompletableFuture<T> a; |
583 |
Object r; Throwable x; Function<? super T,? extends V> f; |
584 |
if ((d = dep) == null || (f = fn) == null |
585 |
|| (a = src) == null || (r = a.result) == null) |
586 |
return null; |
587 |
tryComplete: if (d.result == null) { |
588 |
if (r instanceof AltResult) { |
589 |
if ((x = ((AltResult)r).ex) != null) { |
590 |
d.completeThrowable(x, r); |
591 |
break tryComplete; |
592 |
} |
593 |
r = null; |
594 |
} |
595 |
try { |
596 |
if (mode <= 0 && !claim()) |
597 |
return null; |
598 |
else { |
599 |
@SuppressWarnings("unchecked") T t = (T) r; |
600 |
d.completeValue(f.apply(t)); |
601 |
} |
602 |
} catch (Throwable ex) { |
603 |
d.completeThrowable(ex); |
604 |
} |
605 |
} |
606 |
dep = null; src = null; fn = null; |
607 |
return d.postFire(a, mode); |
608 |
} |
609 |
} |
610 |
|
611 |
private <V> CompletableFuture<V> uniApplyStage( |
612 |
Executor e, Function<? super T,? extends V> f) { |
613 |
if (f == null) throw new NullPointerException(); |
614 |
Object r; |
615 |
if ((r = result) != null) |
616 |
return uniApplyNow(r, e, f); |
617 |
CompletableFuture<V> d = newIncompleteFuture(); |
618 |
unipush(new UniApply<T,V>(e, d, this, f)); |
619 |
return d; |
620 |
} |
621 |
|
622 |
private <V> CompletableFuture<V> uniApplyNow( |
623 |
Object r, Executor e, Function<? super T,? extends V> f) { |
624 |
Throwable x; |
625 |
CompletableFuture<V> d = newIncompleteFuture(); |
626 |
if (r instanceof AltResult) { |
627 |
if ((x = ((AltResult)r).ex) != null) { |
628 |
d.result = encodeThrowable(x, r); |
629 |
return d; |
630 |
} |
631 |
r = null; |
632 |
} |
633 |
try { |
634 |
if (e != null) { |
635 |
e.execute(new UniApply<T,V>(null, d, this, f)); |
636 |
} else { |
637 |
@SuppressWarnings("unchecked") T t = (T) r; |
638 |
d.result = d.encodeValue(f.apply(t)); |
639 |
} |
640 |
} catch (Throwable ex) { |
641 |
d.result = encodeThrowable(ex); |
642 |
} |
643 |
return d; |
644 |
} |
645 |
|
646 |
@SuppressWarnings("serial") |
647 |
static final class UniAccept<T> extends UniCompletion<T,Void> { |
648 |
Consumer<? super T> fn; |
649 |
UniAccept(Executor executor, CompletableFuture<Void> dep, |
650 |
CompletableFuture<T> src, Consumer<? super T> fn) { |
651 |
super(executor, dep, src); this.fn = fn; |
652 |
} |
653 |
final CompletableFuture<Void> tryFire(int mode) { |
654 |
CompletableFuture<Void> d; CompletableFuture<T> a; |
655 |
Object r; Throwable x; Consumer<? super T> f; |
656 |
if ((d = dep) == null || (f = fn) == null |
657 |
|| (a = src) == null || (r = a.result) == null) |
658 |
return null; |
659 |
tryComplete: if (d.result == null) { |
660 |
if (r instanceof AltResult) { |
661 |
if ((x = ((AltResult)r).ex) != null) { |
662 |
d.completeThrowable(x, r); |
663 |
break tryComplete; |
664 |
} |
665 |
r = null; |
666 |
} |
667 |
try { |
668 |
if (mode <= 0 && !claim()) |
669 |
return null; |
670 |
else { |
671 |
@SuppressWarnings("unchecked") T t = (T) r; |
672 |
f.accept(t); |
673 |
d.completeNull(); |
674 |
} |
675 |
} catch (Throwable ex) { |
676 |
d.completeThrowable(ex); |
677 |
} |
678 |
} |
679 |
dep = null; src = null; fn = null; |
680 |
return d.postFire(a, mode); |
681 |
} |
682 |
} |
683 |
|
684 |
private CompletableFuture<Void> uniAcceptStage(Executor e, |
685 |
Consumer<? super T> f) { |
686 |
if (f == null) throw new NullPointerException(); |
687 |
Object r; |
688 |
if ((r = result) != null) |
689 |
return uniAcceptNow(r, e, f); |
690 |
CompletableFuture<Void> d = newIncompleteFuture(); |
691 |
unipush(new UniAccept<T>(e, d, this, f)); |
692 |
return d; |
693 |
} |
694 |
|
695 |
private CompletableFuture<Void> uniAcceptNow( |
696 |
Object r, Executor e, Consumer<? super T> f) { |
697 |
Throwable x; |
698 |
CompletableFuture<Void> d = newIncompleteFuture(); |
699 |
if (r instanceof AltResult) { |
700 |
if ((x = ((AltResult)r).ex) != null) { |
701 |
d.result = encodeThrowable(x, r); |
702 |
return d; |
703 |
} |
704 |
r = null; |
705 |
} |
706 |
try { |
707 |
if (e != null) { |
708 |
e.execute(new UniAccept<T>(null, d, this, f)); |
709 |
} else { |
710 |
@SuppressWarnings("unchecked") T t = (T) r; |
711 |
f.accept(t); |
712 |
d.result = NIL; |
713 |
} |
714 |
} catch (Throwable ex) { |
715 |
d.result = encodeThrowable(ex); |
716 |
} |
717 |
return d; |
718 |
} |
719 |
|
720 |
@SuppressWarnings("serial") |
721 |
static final class UniRun<T> extends UniCompletion<T,Void> { |
722 |
Runnable fn; |
723 |
UniRun(Executor executor, CompletableFuture<Void> dep, |
724 |
CompletableFuture<T> src, Runnable fn) { |
725 |
super(executor, dep, src); this.fn = fn; |
726 |
} |
727 |
final CompletableFuture<Void> tryFire(int mode) { |
728 |
CompletableFuture<Void> d; CompletableFuture<T> a; |
729 |
Object r; Throwable x; Runnable f; |
730 |
if ((d = dep) == null || (f = fn) == null |
731 |
|| (a = src) == null || (r = a.result) == null) |
732 |
return null; |
733 |
if (d.result == null) { |
734 |
if (r instanceof AltResult && (x = ((AltResult)r).ex) != null) |
735 |
d.completeThrowable(x, r); |
736 |
else |
737 |
try { |
738 |
if (mode <= 0 && !claim()) |
739 |
return null; |
740 |
else { |
741 |
f.run(); |
742 |
d.completeNull(); |
743 |
} |
744 |
} catch (Throwable ex) { |
745 |
d.completeThrowable(ex); |
746 |
} |
747 |
} |
748 |
dep = null; src = null; fn = null; |
749 |
return d.postFire(a, mode); |
750 |
} |
751 |
} |
752 |
|
753 |
private CompletableFuture<Void> uniRunStage(Executor e, Runnable f) { |
754 |
if (f == null) throw new NullPointerException(); |
755 |
Object r; |
756 |
if ((r = result) != null) |
757 |
return uniRunNow(r, e, f); |
758 |
CompletableFuture<Void> d = newIncompleteFuture(); |
759 |
unipush(new UniRun<T>(e, d, this, f)); |
760 |
return d; |
761 |
} |
762 |
|
763 |
private CompletableFuture<Void> uniRunNow(Object r, Executor e, Runnable f) { |
764 |
Throwable x; |
765 |
CompletableFuture<Void> d = newIncompleteFuture(); |
766 |
if (r instanceof AltResult && (x = ((AltResult)r).ex) != null) |
767 |
d.result = encodeThrowable(x, r); |
768 |
else |
769 |
try { |
770 |
if (e != null) { |
771 |
e.execute(new UniRun<T>(null, d, this, f)); |
772 |
} else { |
773 |
f.run(); |
774 |
d.result = NIL; |
775 |
} |
776 |
} catch (Throwable ex) { |
777 |
d.result = encodeThrowable(ex); |
778 |
} |
779 |
return d; |
780 |
} |
781 |
|
782 |
@SuppressWarnings("serial") |
783 |
static final class UniWhenComplete<T> extends UniCompletion<T,T> { |
784 |
BiConsumer<? super T, ? super Throwable> fn; |
785 |
UniWhenComplete(Executor executor, CompletableFuture<T> dep, |
786 |
CompletableFuture<T> src, |
787 |
BiConsumer<? super T, ? super Throwable> fn) { |
788 |
super(executor, dep, src); this.fn = fn; |
789 |
} |
790 |
final CompletableFuture<T> tryFire(int mode) { |
791 |
CompletableFuture<T> d; CompletableFuture<T> a; |
792 |
Object r; BiConsumer<? super T, ? super Throwable> f; |
793 |
if ((d = dep) == null || (f = fn) == null |
794 |
|| (a = src) == null || (r = a.result) == null |
795 |
|| !d.uniWhenComplete(r, f, mode > 0 ? null : this)) |
796 |
return null; |
797 |
dep = null; src = null; fn = null; |
798 |
return d.postFire(a, mode); |
799 |
} |
800 |
} |
801 |
|
802 |
final boolean uniWhenComplete(Object r, |
803 |
BiConsumer<? super T,? super Throwable> f, |
804 |
UniWhenComplete<T> c) { |
805 |
T t; Throwable x = null; |
806 |
if (result == null) { |
807 |
try { |
808 |
if (c != null && !c.claim()) |
809 |
return false; |
810 |
if (r instanceof AltResult) { |
811 |
x = ((AltResult)r).ex; |
812 |
t = null; |
813 |
} else { |
814 |
@SuppressWarnings("unchecked") T tr = (T) r; |
815 |
t = tr; |
816 |
} |
817 |
f.accept(t, x); |
818 |
if (x == null) { |
819 |
internalComplete(r); |
820 |
return true; |
821 |
} |
822 |
} catch (Throwable ex) { |
823 |
if (x == null) |
824 |
x = ex; |
825 |
else if (x != ex) |
826 |
x.addSuppressed(ex); |
827 |
} |
828 |
completeThrowable(x, r); |
829 |
} |
830 |
return true; |
831 |
} |
832 |
|
833 |
private CompletableFuture<T> uniWhenCompleteStage( |
834 |
Executor e, BiConsumer<? super T, ? super Throwable> f) { |
835 |
if (f == null) throw new NullPointerException(); |
836 |
CompletableFuture<T> d = newIncompleteFuture(); |
837 |
Object r; |
838 |
if ((r = result) == null) |
839 |
unipush(new UniWhenComplete<T>(e, d, this, f)); |
840 |
else if (e == null) |
841 |
d.uniWhenComplete(r, f, null); |
842 |
else { |
843 |
try { |
844 |
e.execute(new UniWhenComplete<T>(null, d, this, f)); |
845 |
} catch (Throwable ex) { |
846 |
d.result = encodeThrowable(ex); |
847 |
} |
848 |
} |
849 |
return d; |
850 |
} |
851 |
|
852 |
@SuppressWarnings("serial") |
853 |
static final class UniHandle<T,V> extends UniCompletion<T,V> { |
854 |
BiFunction<? super T, Throwable, ? extends V> fn; |
855 |
UniHandle(Executor executor, CompletableFuture<V> dep, |
856 |
CompletableFuture<T> src, |
857 |
BiFunction<? super T, Throwable, ? extends V> fn) { |
858 |
super(executor, dep, src); this.fn = fn; |
859 |
} |
860 |
final CompletableFuture<V> tryFire(int mode) { |
861 |
CompletableFuture<V> d; CompletableFuture<T> a; |
862 |
Object r; BiFunction<? super T, Throwable, ? extends V> f; |
863 |
if ((d = dep) == null || (f = fn) == null |
864 |
|| (a = src) == null || (r = a.result) == null |
865 |
|| !d.uniHandle(r, f, mode > 0 ? null : this)) |
866 |
return null; |
867 |
dep = null; src = null; fn = null; |
868 |
return d.postFire(a, mode); |
869 |
} |
870 |
} |
871 |
|
872 |
final <S> boolean uniHandle(Object r, |
873 |
BiFunction<? super S, Throwable, ? extends T> f, |
874 |
UniHandle<S,T> c) { |
875 |
S s; Throwable x; |
876 |
if (result == null) { |
877 |
try { |
878 |
if (c != null && !c.claim()) |
879 |
return false; |
880 |
if (r instanceof AltResult) { |
881 |
x = ((AltResult)r).ex; |
882 |
s = null; |
883 |
} else { |
884 |
x = null; |
885 |
@SuppressWarnings("unchecked") S ss = (S) r; |
886 |
s = ss; |
887 |
} |
888 |
completeValue(f.apply(s, x)); |
889 |
} catch (Throwable ex) { |
890 |
completeThrowable(ex); |
891 |
} |
892 |
} |
893 |
return true; |
894 |
} |
895 |
|
896 |
private <V> CompletableFuture<V> uniHandleStage( |
897 |
Executor e, BiFunction<? super T, Throwable, ? extends V> f) { |
898 |
if (f == null) throw new NullPointerException(); |
899 |
CompletableFuture<V> d = newIncompleteFuture(); |
900 |
Object r; |
901 |
if ((r = result) == null) |
902 |
unipush(new UniHandle<T,V>(e, d, this, f)); |
903 |
else if (e == null) |
904 |
d.uniHandle(r, f, null); |
905 |
else { |
906 |
try { |
907 |
e.execute(new UniHandle<T,V>(null, d, this, f)); |
908 |
} catch (Throwable ex) { |
909 |
d.result = encodeThrowable(ex); |
910 |
} |
911 |
} |
912 |
return d; |
913 |
} |
914 |
|
915 |
@SuppressWarnings("serial") |
916 |
static final class UniExceptionally<T> extends UniCompletion<T,T> { |
917 |
Function<? super Throwable, ? extends T> fn; |
918 |
UniExceptionally(CompletableFuture<T> dep, CompletableFuture<T> src, |
919 |
Function<? super Throwable, ? extends T> fn) { |
920 |
super(null, dep, src); this.fn = fn; |
921 |
} |
922 |
final CompletableFuture<T> tryFire(int mode) { // never ASYNC |
923 |
// assert mode != ASYNC; |
924 |
CompletableFuture<T> d; CompletableFuture<T> a; |
925 |
Object r; Function<? super Throwable, ? extends T> f; |
926 |
if ((d = dep) == null || (f = fn) == null |
927 |
|| (a = src) == null || (r = a.result) == null |
928 |
|| !d.uniExceptionally(r, f, this)) |
929 |
return null; |
930 |
dep = null; src = null; fn = null; |
931 |
return d.postFire(a, mode); |
932 |
} |
933 |
} |
934 |
|
935 |
final boolean uniExceptionally(Object r, |
936 |
Function<? super Throwable, ? extends T> f, |
937 |
UniExceptionally<T> c) { |
938 |
Throwable x; |
939 |
if (result == null) { |
940 |
try { |
941 |
if (r instanceof AltResult && (x = ((AltResult)r).ex) != null) { |
942 |
if (c != null && !c.claim()) |
943 |
return false; |
944 |
completeValue(f.apply(x)); |
945 |
} else |
946 |
internalComplete(r); |
947 |
} catch (Throwable ex) { |
948 |
completeThrowable(ex); |
949 |
} |
950 |
} |
951 |
return true; |
952 |
} |
953 |
|
954 |
private CompletableFuture<T> uniExceptionallyStage( |
955 |
Function<Throwable, ? extends T> f) { |
956 |
if (f == null) throw new NullPointerException(); |
957 |
CompletableFuture<T> d = newIncompleteFuture(); |
958 |
Object r; |
959 |
if ((r = result) == null) |
960 |
unipush(new UniExceptionally<T>(d, this, f)); |
961 |
else |
962 |
d.uniExceptionally(r, f, null); |
963 |
return d; |
964 |
} |
965 |
|
966 |
@SuppressWarnings("serial") |
967 |
static final class UniRelay<T> extends UniCompletion<T,T> { |
968 |
UniRelay(CompletableFuture<T> dep, CompletableFuture<T> src) { |
969 |
super(null, dep, src); |
970 |
} |
971 |
final CompletableFuture<T> tryFire(int mode) { |
972 |
CompletableFuture<T> d; CompletableFuture<T> a; Object r; |
973 |
if ((d = dep) == null |
974 |
|| (a = src) == null || (r = a.result) == null) |
975 |
return null; |
976 |
if (d.result == null) |
977 |
d.completeRelay(r); |
978 |
src = null; dep = null; |
979 |
return d.postFire(a, mode); |
980 |
} |
981 |
} |
982 |
|
983 |
private CompletableFuture<T> uniCopyStage() { |
984 |
Object r; |
985 |
CompletableFuture<T> d = newIncompleteFuture(); |
986 |
if ((r = result) != null) |
987 |
d.result = encodeRelay(r); |
988 |
else |
989 |
unipush(new UniRelay<T>(d, this)); |
990 |
return d; |
991 |
} |
992 |
|
993 |
private MinimalStage<T> uniAsMinimalStage() { |
994 |
Object r; |
995 |
if ((r = result) != null) |
996 |
return new MinimalStage<T>(encodeRelay(r)); |
997 |
MinimalStage<T> d = new MinimalStage<T>(); |
998 |
unipush(new UniRelay<T>(d, this)); |
999 |
return d; |
1000 |
} |
1001 |
|
1002 |
@SuppressWarnings("serial") |
1003 |
static final class UniCompose<T,V> extends UniCompletion<T,V> { |
1004 |
Function<? super T, ? extends CompletionStage<V>> fn; |
1005 |
UniCompose(Executor executor, CompletableFuture<V> dep, |
1006 |
CompletableFuture<T> src, |
1007 |
Function<? super T, ? extends CompletionStage<V>> fn) { |
1008 |
super(executor, dep, src); this.fn = fn; |
1009 |
} |
1010 |
final CompletableFuture<V> tryFire(int mode) { |
1011 |
CompletableFuture<V> d; CompletableFuture<T> a; |
1012 |
Function<? super T, ? extends CompletionStage<V>> f; |
1013 |
Object r; Throwable x; |
1014 |
if ((d = dep) == null || (f = fn) == null |
1015 |
|| (a = src) == null || (r = a.result) == null) |
1016 |
return null; |
1017 |
tryComplete: if (d.result == null) { |
1018 |
if (r instanceof AltResult) { |
1019 |
if ((x = ((AltResult)r).ex) != null) { |
1020 |
d.completeThrowable(x, r); |
1021 |
break tryComplete; |
1022 |
} |
1023 |
r = null; |
1024 |
} |
1025 |
try { |
1026 |
if (mode <= 0 && !claim()) |
1027 |
return null; |
1028 |
@SuppressWarnings("unchecked") T t = (T) r; |
1029 |
CompletableFuture<V> g = f.apply(t).toCompletableFuture(); |
1030 |
if ((r = g.result) != null) |
1031 |
d.completeRelay(r); |
1032 |
else { |
1033 |
g.unipush(new UniRelay<V>(d, g)); |
1034 |
if (d.result == null) |
1035 |
return null; |
1036 |
} |
1037 |
} catch (Throwable ex) { |
1038 |
d.completeThrowable(ex); |
1039 |
} |
1040 |
} |
1041 |
dep = null; src = null; fn = null; |
1042 |
return d.postFire(a, mode); |
1043 |
} |
1044 |
} |
1045 |
|
1046 |
private <V> CompletableFuture<V> uniComposeStage( |
1047 |
Executor e, Function<? super T, ? extends CompletionStage<V>> f) { |
1048 |
if (f == null) throw new NullPointerException(); |
1049 |
CompletableFuture<V> d = newIncompleteFuture(); |
1050 |
Object r, s; Throwable x; |
1051 |
if ((r = result) == null) |
1052 |
unipush(new UniCompose<T,V>(e, d, this, f)); |
1053 |
else if (e == null) { |
1054 |
if (r instanceof AltResult) { |
1055 |
if ((x = ((AltResult)r).ex) != null) { |
1056 |
d.result = encodeThrowable(x, r); |
1057 |
return d; |
1058 |
} |
1059 |
r = null; |
1060 |
} |
1061 |
try { |
1062 |
@SuppressWarnings("unchecked") T t = (T) r; |
1063 |
CompletableFuture<V> g = f.apply(t).toCompletableFuture(); |
1064 |
if ((s = g.result) != null) |
1065 |
d.result = encodeRelay(s); |
1066 |
else { |
1067 |
g.unipush(new UniRelay<V>(d, g)); |
1068 |
} |
1069 |
} catch (Throwable ex) { |
1070 |
d.result = encodeThrowable(ex); |
1071 |
} |
1072 |
} |
1073 |
else |
1074 |
try { |
1075 |
e.execute(new UniCompose<T,V>(null, d, this, f)); |
1076 |
} catch (Throwable ex) { |
1077 |
d.result = encodeThrowable(ex); |
1078 |
} |
1079 |
return d; |
1080 |
} |
1081 |
|
1082 |
/* ------------- Two-input Completions -------------- */ |
1083 |
|
1084 |
/** A Completion for an action with two sources */ |
1085 |
@SuppressWarnings("serial") |
1086 |
abstract static class BiCompletion<T,U,V> extends UniCompletion<T,V> { |
1087 |
CompletableFuture<U> snd; // second source for action |
1088 |
BiCompletion(Executor executor, CompletableFuture<V> dep, |
1089 |
CompletableFuture<T> src, CompletableFuture<U> snd) { |
1090 |
super(executor, dep, src); this.snd = snd; |
1091 |
} |
1092 |
} |
1093 |
|
1094 |
/** A Completion delegating to a BiCompletion */ |
1095 |
@SuppressWarnings("serial") |
1096 |
static final class CoCompletion extends Completion { |
1097 |
BiCompletion<?,?,?> base; |
1098 |
CoCompletion(BiCompletion<?,?,?> base) { this.base = base; } |
1099 |
final CompletableFuture<?> tryFire(int mode) { |
1100 |
BiCompletion<?,?,?> c; CompletableFuture<?> d; |
1101 |
if ((c = base) == null || (d = c.tryFire(mode)) == null) |
1102 |
return null; |
1103 |
base = null; // detach |
1104 |
return d; |
1105 |
} |
1106 |
final boolean isLive() { |
1107 |
BiCompletion<?,?,?> c; |
1108 |
return (c = base) != null |
1109 |
// && c.isLive() |
1110 |
&& c.dep != null; |
1111 |
} |
1112 |
} |
1113 |
|
1114 |
/** |
1115 |
* Pushes completion to this and b unless both done. |
1116 |
* Caller should first check that either result or b.result is null. |
1117 |
*/ |
1118 |
final void bipush(CompletableFuture<?> b, BiCompletion<?,?,?> c) { |
1119 |
if (c != null) { |
1120 |
while (result == null) { |
1121 |
if (tryPushStack(c)) { |
1122 |
if (b.result == null) |
1123 |
b.unipush(new CoCompletion(c)); |
1124 |
else if (result != null) |
1125 |
c.tryFire(SYNC); |
1126 |
return; |
1127 |
} |
1128 |
} |
1129 |
b.unipush(c); |
1130 |
} |
1131 |
} |
1132 |
|
1133 |
/** Post-processing after successful BiCompletion tryFire. */ |
1134 |
final CompletableFuture<T> postFire(CompletableFuture<?> a, |
1135 |
CompletableFuture<?> b, int mode) { |
1136 |
if (b != null && b.stack != null) { // clean second source |
1137 |
Object r; |
1138 |
if ((r = b.result) == null) |
1139 |
b.cleanStack(); |
1140 |
if (mode >= 0 && (r != null || b.result != null)) |
1141 |
b.postComplete(); |
1142 |
} |
1143 |
return postFire(a, mode); |
1144 |
} |
1145 |
|
1146 |
@SuppressWarnings("serial") |
1147 |
static final class BiApply<T,U,V> extends BiCompletion<T,U,V> { |
1148 |
BiFunction<? super T,? super U,? extends V> fn; |
1149 |
BiApply(Executor executor, CompletableFuture<V> dep, |
1150 |
CompletableFuture<T> src, CompletableFuture<U> snd, |
1151 |
BiFunction<? super T,? super U,? extends V> fn) { |
1152 |
super(executor, dep, src, snd); this.fn = fn; |
1153 |
} |
1154 |
final CompletableFuture<V> tryFire(int mode) { |
1155 |
CompletableFuture<V> d; |
1156 |
CompletableFuture<T> a; |
1157 |
CompletableFuture<U> b; |
1158 |
Object r, s; BiFunction<? super T,? super U,? extends V> f; |
1159 |
if ((d = dep) == null || (f = fn) == null |
1160 |
|| (a = src) == null || (r = a.result) == null |
1161 |
|| (b = snd) == null || (s = b.result) == null |
1162 |
|| !d.biApply(r, s, f, mode > 0 ? null : this)) |
1163 |
return null; |
1164 |
dep = null; src = null; snd = null; fn = null; |
1165 |
return d.postFire(a, b, mode); |
1166 |
} |
1167 |
} |
1168 |
|
1169 |
final <R,S> boolean biApply(Object r, Object s, |
1170 |
BiFunction<? super R,? super S,? extends T> f, |
1171 |
BiApply<R,S,T> c) { |
1172 |
Throwable x; |
1173 |
tryComplete: if (result == null) { |
1174 |
if (r instanceof AltResult) { |
1175 |
if ((x = ((AltResult)r).ex) != null) { |
1176 |
completeThrowable(x, r); |
1177 |
break tryComplete; |
1178 |
} |
1179 |
r = null; |
1180 |
} |
1181 |
if (s instanceof AltResult) { |
1182 |
if ((x = ((AltResult)s).ex) != null) { |
1183 |
completeThrowable(x, s); |
1184 |
break tryComplete; |
1185 |
} |
1186 |
s = null; |
1187 |
} |
1188 |
try { |
1189 |
if (c != null && !c.claim()) |
1190 |
return false; |
1191 |
@SuppressWarnings("unchecked") R rr = (R) r; |
1192 |
@SuppressWarnings("unchecked") S ss = (S) s; |
1193 |
completeValue(f.apply(rr, ss)); |
1194 |
} catch (Throwable ex) { |
1195 |
completeThrowable(ex); |
1196 |
} |
1197 |
} |
1198 |
return true; |
1199 |
} |
1200 |
|
1201 |
private <U,V> CompletableFuture<V> biApplyStage( |
1202 |
Executor e, CompletionStage<U> o, |
1203 |
BiFunction<? super T,? super U,? extends V> f) { |
1204 |
CompletableFuture<U> b; Object r, s; |
1205 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1206 |
throw new NullPointerException(); |
1207 |
CompletableFuture<V> d = newIncompleteFuture(); |
1208 |
if ((r = result) == null || (s = b.result) == null) |
1209 |
bipush(b, new BiApply<T,U,V>(e, d, this, b, f)); |
1210 |
else if (e == null) |
1211 |
d.biApply(r, s, f, null); |
1212 |
else |
1213 |
try { |
1214 |
e.execute(new BiApply<T,U,V>(null, d, this, b, f)); |
1215 |
} catch (Throwable ex) { |
1216 |
d.result = encodeThrowable(ex); |
1217 |
} |
1218 |
return d; |
1219 |
} |
1220 |
|
1221 |
@SuppressWarnings("serial") |
1222 |
static final class BiAccept<T,U> extends BiCompletion<T,U,Void> { |
1223 |
BiConsumer<? super T,? super U> fn; |
1224 |
BiAccept(Executor executor, CompletableFuture<Void> dep, |
1225 |
CompletableFuture<T> src, CompletableFuture<U> snd, |
1226 |
BiConsumer<? super T,? super U> fn) { |
1227 |
super(executor, dep, src, snd); this.fn = fn; |
1228 |
} |
1229 |
final CompletableFuture<Void> tryFire(int mode) { |
1230 |
CompletableFuture<Void> d; |
1231 |
CompletableFuture<T> a; |
1232 |
CompletableFuture<U> b; |
1233 |
Object r, s; BiConsumer<? super T,? super U> f; |
1234 |
if ((d = dep) == null || (f = fn) == null |
1235 |
|| (a = src) == null || (r = a.result) == null |
1236 |
|| (b = snd) == null || (s = b.result) == null |
1237 |
|| !d.biAccept(r, s, f, mode > 0 ? null : this)) |
1238 |
return null; |
1239 |
dep = null; src = null; snd = null; fn = null; |
1240 |
return d.postFire(a, b, mode); |
1241 |
} |
1242 |
} |
1243 |
|
1244 |
final <R,S> boolean biAccept(Object r, Object s, |
1245 |
BiConsumer<? super R,? super S> f, |
1246 |
BiAccept<R,S> c) { |
1247 |
Throwable x; |
1248 |
tryComplete: if (result == null) { |
1249 |
if (r instanceof AltResult) { |
1250 |
if ((x = ((AltResult)r).ex) != null) { |
1251 |
completeThrowable(x, r); |
1252 |
break tryComplete; |
1253 |
} |
1254 |
r = null; |
1255 |
} |
1256 |
if (s instanceof AltResult) { |
1257 |
if ((x = ((AltResult)s).ex) != null) { |
1258 |
completeThrowable(x, s); |
1259 |
break tryComplete; |
1260 |
} |
1261 |
s = null; |
1262 |
} |
1263 |
try { |
1264 |
if (c != null && !c.claim()) |
1265 |
return false; |
1266 |
@SuppressWarnings("unchecked") R rr = (R) r; |
1267 |
@SuppressWarnings("unchecked") S ss = (S) s; |
1268 |
f.accept(rr, ss); |
1269 |
completeNull(); |
1270 |
} catch (Throwable ex) { |
1271 |
completeThrowable(ex); |
1272 |
} |
1273 |
} |
1274 |
return true; |
1275 |
} |
1276 |
|
1277 |
private <U> CompletableFuture<Void> biAcceptStage( |
1278 |
Executor e, CompletionStage<U> o, |
1279 |
BiConsumer<? super T,? super U> f) { |
1280 |
CompletableFuture<U> b; Object r, s; |
1281 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1282 |
throw new NullPointerException(); |
1283 |
CompletableFuture<Void> d = newIncompleteFuture(); |
1284 |
if ((r = result) == null || (s = b.result) == null) |
1285 |
bipush(b, new BiAccept<T,U>(e, d, this, b, f)); |
1286 |
else if (e == null) |
1287 |
d.biAccept(r, s, f, null); |
1288 |
else |
1289 |
try { |
1290 |
e.execute(new BiAccept<T,U>(null, d, this, b, f)); |
1291 |
} catch (Throwable ex) { |
1292 |
d.result = encodeThrowable(ex); |
1293 |
} |
1294 |
return d; |
1295 |
} |
1296 |
|
1297 |
@SuppressWarnings("serial") |
1298 |
static final class BiRun<T,U> extends BiCompletion<T,U,Void> { |
1299 |
Runnable fn; |
1300 |
BiRun(Executor executor, CompletableFuture<Void> dep, |
1301 |
CompletableFuture<T> src, |
1302 |
CompletableFuture<U> snd, |
1303 |
Runnable fn) { |
1304 |
super(executor, dep, src, snd); this.fn = fn; |
1305 |
} |
1306 |
final CompletableFuture<Void> tryFire(int mode) { |
1307 |
CompletableFuture<Void> d; |
1308 |
CompletableFuture<T> a; |
1309 |
CompletableFuture<U> b; |
1310 |
Object r, s; Runnable f; |
1311 |
if ((d = dep) == null || (f = fn) == null |
1312 |
|| (a = src) == null || (r = a.result) == null |
1313 |
|| (b = snd) == null || (s = b.result) == null |
1314 |
|| !d.biRun(r, s, f, mode > 0 ? null : this)) |
1315 |
return null; |
1316 |
dep = null; src = null; snd = null; fn = null; |
1317 |
return d.postFire(a, b, mode); |
1318 |
} |
1319 |
} |
1320 |
|
1321 |
final boolean biRun(Object r, Object s, Runnable f, BiRun<?,?> c) { |
1322 |
Throwable x; Object z; |
1323 |
if (result == null) { |
1324 |
if ((r instanceof AltResult |
1325 |
&& (x = ((AltResult)(z = r)).ex) != null) || |
1326 |
(s instanceof AltResult |
1327 |
&& (x = ((AltResult)(z = s)).ex) != null)) |
1328 |
completeThrowable(x, z); |
1329 |
else |
1330 |
try { |
1331 |
if (c != null && !c.claim()) |
1332 |
return false; |
1333 |
f.run(); |
1334 |
completeNull(); |
1335 |
} catch (Throwable ex) { |
1336 |
completeThrowable(ex); |
1337 |
} |
1338 |
} |
1339 |
return true; |
1340 |
} |
1341 |
|
1342 |
private CompletableFuture<Void> biRunStage(Executor e, CompletionStage<?> o, |
1343 |
Runnable f) { |
1344 |
CompletableFuture<?> b; Object r, s; |
1345 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1346 |
throw new NullPointerException(); |
1347 |
CompletableFuture<Void> d = newIncompleteFuture(); |
1348 |
if ((r = result) == null || (s = b.result) == null) |
1349 |
bipush(b, new BiRun<>(e, d, this, b, f)); |
1350 |
else if (e == null) |
1351 |
d.biRun(r, s, f, null); |
1352 |
else |
1353 |
try { |
1354 |
e.execute(new BiRun<>(null, d, this, b, f)); |
1355 |
} catch (Throwable ex) { |
1356 |
d.result = encodeThrowable(ex); |
1357 |
} |
1358 |
return d; |
1359 |
} |
1360 |
|
1361 |
@SuppressWarnings("serial") |
1362 |
static final class BiRelay<T,U> extends BiCompletion<T,U,Void> { // for And |
1363 |
BiRelay(CompletableFuture<Void> dep, |
1364 |
CompletableFuture<T> src, |
1365 |
CompletableFuture<U> snd) { |
1366 |
super(null, dep, src, snd); |
1367 |
} |
1368 |
final CompletableFuture<Void> tryFire(int mode) { |
1369 |
CompletableFuture<Void> d; |
1370 |
CompletableFuture<T> a; |
1371 |
CompletableFuture<U> b; |
1372 |
Object r, s, z; Throwable x; |
1373 |
if ((d = dep) == null |
1374 |
|| (a = src) == null || (r = a.result) == null |
1375 |
|| (b = snd) == null || (s = b.result) == null) |
1376 |
return null; |
1377 |
if (d.result == null) { |
1378 |
if ((r instanceof AltResult |
1379 |
&& (x = ((AltResult)(z = r)).ex) != null) || |
1380 |
(s instanceof AltResult |
1381 |
&& (x = ((AltResult)(z = s)).ex) != null)) |
1382 |
d.completeThrowable(x, z); |
1383 |
else |
1384 |
d.completeNull(); |
1385 |
} |
1386 |
src = null; snd = null; dep = null; |
1387 |
return d.postFire(a, b, mode); |
1388 |
} |
1389 |
} |
1390 |
|
1391 |
/** Recursively constructs a tree of completions. */ |
1392 |
static CompletableFuture<Void> andTree(CompletableFuture<?>[] cfs, |
1393 |
int lo, int hi) { |
1394 |
CompletableFuture<Void> d = new CompletableFuture<Void>(); |
1395 |
if (lo > hi) // empty |
1396 |
d.result = NIL; |
1397 |
else { |
1398 |
CompletableFuture<?> a, b; Object r, s, z; Throwable x; |
1399 |
int mid = (lo + hi) >>> 1; |
1400 |
if ((a = (lo == mid ? cfs[lo] : |
1401 |
andTree(cfs, lo, mid))) == null || |
1402 |
(b = (lo == hi ? a : (hi == mid+1) ? cfs[hi] : |
1403 |
andTree(cfs, mid+1, hi))) == null) |
1404 |
throw new NullPointerException(); |
1405 |
if ((r = a.result) == null || (s = b.result) == null) |
1406 |
a.bipush(b, new BiRelay<>(d, a, b)); |
1407 |
else if ((r instanceof AltResult |
1408 |
&& (x = ((AltResult)(z = r)).ex) != null) || |
1409 |
(s instanceof AltResult |
1410 |
&& (x = ((AltResult)(z = s)).ex) != null)) |
1411 |
d.result = encodeThrowable(x, z); |
1412 |
else |
1413 |
d.result = NIL; |
1414 |
} |
1415 |
return d; |
1416 |
} |
1417 |
|
1418 |
/* ------------- Projected (Ored) BiCompletions -------------- */ |
1419 |
|
1420 |
/** |
1421 |
* Pushes completion to this and b unless either done. |
1422 |
* Caller should first check that result and b.result are both null. |
1423 |
*/ |
1424 |
final void orpush(CompletableFuture<?> b, BiCompletion<?,?,?> c) { |
1425 |
if (c != null) { |
1426 |
while (!tryPushStack(c)) { |
1427 |
if (result != null) { |
1428 |
NEXT.set(c, null); |
1429 |
break; |
1430 |
} |
1431 |
} |
1432 |
if (result != null) |
1433 |
c.tryFire(SYNC); |
1434 |
else |
1435 |
b.unipush(new CoCompletion(c)); |
1436 |
} |
1437 |
} |
1438 |
|
1439 |
@SuppressWarnings("serial") |
1440 |
static final class OrApply<T,U extends T,V> extends BiCompletion<T,U,V> { |
1441 |
Function<? super T,? extends V> fn; |
1442 |
OrApply(Executor executor, CompletableFuture<V> dep, |
1443 |
CompletableFuture<T> src, |
1444 |
CompletableFuture<U> snd, |
1445 |
Function<? super T,? extends V> fn) { |
1446 |
super(executor, dep, src, snd); this.fn = fn; |
1447 |
} |
1448 |
final CompletableFuture<V> tryFire(int mode) { |
1449 |
CompletableFuture<V> d; |
1450 |
CompletableFuture<T> a; |
1451 |
CompletableFuture<U> b; |
1452 |
Object r; Throwable x; Function<? super T,? extends V> f; |
1453 |
if ((d = dep) == null || (f = fn) == null |
1454 |
|| (a = src) == null || (b = snd) == null |
1455 |
|| ((r = a.result) == null && (r = b.result) == null)) |
1456 |
return null; |
1457 |
tryComplete: if (d.result == null) { |
1458 |
try { |
1459 |
if (mode <= 0 && !claim()) |
1460 |
return null; |
1461 |
if (r instanceof AltResult) { |
1462 |
if ((x = ((AltResult)r).ex) != null) { |
1463 |
d.completeThrowable(x, r); |
1464 |
break tryComplete; |
1465 |
} |
1466 |
r = null; |
1467 |
} |
1468 |
@SuppressWarnings("unchecked") T t = (T) r; |
1469 |
d.completeValue(f.apply(t)); |
1470 |
} catch (Throwable ex) { |
1471 |
d.completeThrowable(ex); |
1472 |
} |
1473 |
} |
1474 |
dep = null; src = null; snd = null; fn = null; |
1475 |
return d.postFire(a, b, mode); |
1476 |
} |
1477 |
} |
1478 |
|
1479 |
private <U extends T,V> CompletableFuture<V> orApplyStage( |
1480 |
Executor e, CompletionStage<U> o, Function<? super T, ? extends V> f) { |
1481 |
CompletableFuture<U> b; |
1482 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1483 |
throw new NullPointerException(); |
1484 |
|
1485 |
Object r; CompletableFuture<? extends T> z; |
1486 |
if ((r = (z = this).result) != null || |
1487 |
(r = (z = b).result) != null) |
1488 |
return z.uniApplyNow(r, e, f); |
1489 |
|
1490 |
CompletableFuture<V> d = newIncompleteFuture(); |
1491 |
orpush(b, new OrApply<T,U,V>(e, d, this, b, f)); |
1492 |
return d; |
1493 |
} |
1494 |
|
1495 |
@SuppressWarnings("serial") |
1496 |
static final class OrAccept<T,U extends T> extends BiCompletion<T,U,Void> { |
1497 |
Consumer<? super T> fn; |
1498 |
OrAccept(Executor executor, CompletableFuture<Void> dep, |
1499 |
CompletableFuture<T> src, |
1500 |
CompletableFuture<U> snd, |
1501 |
Consumer<? super T> fn) { |
1502 |
super(executor, dep, src, snd); this.fn = fn; |
1503 |
} |
1504 |
final CompletableFuture<Void> tryFire(int mode) { |
1505 |
CompletableFuture<Void> d; |
1506 |
CompletableFuture<T> a; |
1507 |
CompletableFuture<U> b; |
1508 |
Object r; Throwable x; Consumer<? super T> f; |
1509 |
if ((d = dep) == null || (f = fn) == null |
1510 |
|| (a = src) == null || (b = snd) == null |
1511 |
|| ((r = a.result) == null && (r = b.result) == null)) |
1512 |
return null; |
1513 |
tryComplete: if (d.result == null) { |
1514 |
try { |
1515 |
if (mode <= 0 && !claim()) |
1516 |
return null; |
1517 |
if (r instanceof AltResult) { |
1518 |
if ((x = ((AltResult)r).ex) != null) { |
1519 |
d.completeThrowable(x, r); |
1520 |
break tryComplete; |
1521 |
} |
1522 |
r = null; |
1523 |
} |
1524 |
@SuppressWarnings("unchecked") T t = (T) r; |
1525 |
f.accept(t); |
1526 |
d.completeNull(); |
1527 |
} catch (Throwable ex) { |
1528 |
d.completeThrowable(ex); |
1529 |
} |
1530 |
} |
1531 |
dep = null; src = null; snd = null; fn = null; |
1532 |
return d.postFire(a, b, mode); |
1533 |
} |
1534 |
} |
1535 |
|
1536 |
private <U extends T> CompletableFuture<Void> orAcceptStage( |
1537 |
Executor e, CompletionStage<U> o, Consumer<? super T> f) { |
1538 |
CompletableFuture<U> b; |
1539 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1540 |
throw new NullPointerException(); |
1541 |
|
1542 |
Object r; CompletableFuture<? extends T> z; |
1543 |
if ((r = (z = this).result) != null || |
1544 |
(r = (z = b).result) != null) |
1545 |
return z.uniAcceptNow(r, e, f); |
1546 |
|
1547 |
CompletableFuture<Void> d = newIncompleteFuture(); |
1548 |
orpush(b, new OrAccept<T,U>(e, d, this, b, f)); |
1549 |
return d; |
1550 |
} |
1551 |
|
1552 |
@SuppressWarnings("serial") |
1553 |
static final class OrRun<T,U> extends BiCompletion<T,U,Void> { |
1554 |
Runnable fn; |
1555 |
OrRun(Executor executor, CompletableFuture<Void> dep, |
1556 |
CompletableFuture<T> src, |
1557 |
CompletableFuture<U> snd, |
1558 |
Runnable fn) { |
1559 |
super(executor, dep, src, snd); this.fn = fn; |
1560 |
} |
1561 |
final CompletableFuture<Void> tryFire(int mode) { |
1562 |
CompletableFuture<Void> d; |
1563 |
CompletableFuture<T> a; |
1564 |
CompletableFuture<U> b; |
1565 |
Object r; Throwable x; Runnable f; |
1566 |
if ((d = dep) == null || (f = fn) == null |
1567 |
|| (a = src) == null || (b = snd) == null |
1568 |
|| ((r = a.result) == null && (r = b.result) == null)) |
1569 |
return null; |
1570 |
if (d.result == null) { |
1571 |
try { |
1572 |
if (mode <= 0 && !claim()) |
1573 |
return null; |
1574 |
else if (r instanceof AltResult |
1575 |
&& (x = ((AltResult)r).ex) != null) |
1576 |
d.completeThrowable(x, r); |
1577 |
else { |
1578 |
f.run(); |
1579 |
d.completeNull(); |
1580 |
} |
1581 |
} catch (Throwable ex) { |
1582 |
d.completeThrowable(ex); |
1583 |
} |
1584 |
} |
1585 |
dep = null; src = null; snd = null; fn = null; |
1586 |
return d.postFire(a, b, mode); |
1587 |
} |
1588 |
} |
1589 |
|
1590 |
private CompletableFuture<Void> orRunStage(Executor e, CompletionStage<?> o, |
1591 |
Runnable f) { |
1592 |
CompletableFuture<?> b; |
1593 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1594 |
throw new NullPointerException(); |
1595 |
|
1596 |
Object r; CompletableFuture<?> z; |
1597 |
if ((r = (z = this).result) != null || |
1598 |
(r = (z = b).result) != null) |
1599 |
return z.uniRunNow(r, e, f); |
1600 |
|
1601 |
CompletableFuture<Void> d = newIncompleteFuture(); |
1602 |
orpush(b, new OrRun<>(e, d, this, b, f)); |
1603 |
return d; |
1604 |
} |
1605 |
|
1606 |
@SuppressWarnings("serial") |
1607 |
static final class OrRelay<T,U> extends BiCompletion<T,U,Object> { // for Or |
1608 |
OrRelay(CompletableFuture<Object> dep, CompletableFuture<T> src, |
1609 |
CompletableFuture<U> snd) { |
1610 |
super(null, dep, src, snd); |
1611 |
} |
1612 |
final CompletableFuture<Object> tryFire(int mode) { |
1613 |
CompletableFuture<Object> d; |
1614 |
CompletableFuture<T> a; |
1615 |
CompletableFuture<U> b; |
1616 |
Object r; |
1617 |
if ((d = dep) == null |
1618 |
|| (a = src) == null || (b = snd) == null |
1619 |
|| ((r = a.result) == null && (r = b.result) == null)) |
1620 |
return null; |
1621 |
d.completeRelay(r); |
1622 |
src = null; snd = null; dep = null; |
1623 |
return d.postFire(a, b, mode); |
1624 |
} |
1625 |
} |
1626 |
|
1627 |
/** Recursively constructs a tree of completions. */ |
1628 |
static CompletableFuture<Object> orTree(CompletableFuture<?>[] cfs, |
1629 |
int lo, int hi) { |
1630 |
CompletableFuture<Object> d = new CompletableFuture<Object>(); |
1631 |
if (lo <= hi) { |
1632 |
CompletableFuture<?> a, b; Object r; |
1633 |
int mid = (lo + hi) >>> 1; |
1634 |
if ((a = (lo == mid ? cfs[lo] : |
1635 |
orTree(cfs, lo, mid))) == null || |
1636 |
(b = (lo == hi ? a : (hi == mid+1) ? cfs[hi] : |
1637 |
orTree(cfs, mid+1, hi))) == null) |
1638 |
throw new NullPointerException(); |
1639 |
if ((r = a.result) != null && (r = b.result) != null) |
1640 |
d.result = encodeRelay(r); |
1641 |
else |
1642 |
a.orpush(b, new OrRelay<>(d, a, b)); |
1643 |
} |
1644 |
return d; |
1645 |
} |
1646 |
|
1647 |
/* ------------- Zero-input Async forms -------------- */ |
1648 |
|
1649 |
@SuppressWarnings("serial") |
1650 |
static final class AsyncSupply<T> extends ForkJoinTask<Void> |
1651 |
implements Runnable, AsynchronousCompletionTask { |
1652 |
CompletableFuture<T> dep; Supplier<? extends T> fn; |
1653 |
AsyncSupply(CompletableFuture<T> dep, Supplier<? extends T> fn) { |
1654 |
this.dep = dep; this.fn = fn; |
1655 |
} |
1656 |
|
1657 |
public final Void getRawResult() { return null; } |
1658 |
public final void setRawResult(Void v) {} |
1659 |
public final boolean exec() { run(); return false; } |
1660 |
|
1661 |
public void run() { |
1662 |
CompletableFuture<T> d; Supplier<? extends T> f; |
1663 |
if ((d = dep) != null && (f = fn) != null) { |
1664 |
dep = null; fn = null; |
1665 |
if (d.result == null) { |
1666 |
try { |
1667 |
d.completeValue(f.get()); |
1668 |
} catch (Throwable ex) { |
1669 |
d.completeThrowable(ex); |
1670 |
} |
1671 |
} |
1672 |
d.postComplete(); |
1673 |
} |
1674 |
} |
1675 |
} |
1676 |
|
1677 |
static <U> CompletableFuture<U> asyncSupplyStage(Executor e, |
1678 |
Supplier<U> f) { |
1679 |
if (f == null) throw new NullPointerException(); |
1680 |
CompletableFuture<U> d = new CompletableFuture<U>(); |
1681 |
e.execute(new AsyncSupply<U>(d, f)); |
1682 |
return d; |
1683 |
} |
1684 |
|
1685 |
@SuppressWarnings("serial") |
1686 |
static final class AsyncRun extends ForkJoinTask<Void> |
1687 |
implements Runnable, AsynchronousCompletionTask { |
1688 |
CompletableFuture<Void> dep; Runnable fn; |
1689 |
AsyncRun(CompletableFuture<Void> dep, Runnable fn) { |
1690 |
this.dep = dep; this.fn = fn; |
1691 |
} |
1692 |
|
1693 |
public final Void getRawResult() { return null; } |
1694 |
public final void setRawResult(Void v) {} |
1695 |
public final boolean exec() { run(); return false; } |
1696 |
|
1697 |
public void run() { |
1698 |
CompletableFuture<Void> d; Runnable f; |
1699 |
if ((d = dep) != null && (f = fn) != null) { |
1700 |
dep = null; fn = null; |
1701 |
if (d.result == null) { |
1702 |
try { |
1703 |
f.run(); |
1704 |
d.completeNull(); |
1705 |
} catch (Throwable ex) { |
1706 |
d.completeThrowable(ex); |
1707 |
} |
1708 |
} |
1709 |
d.postComplete(); |
1710 |
} |
1711 |
} |
1712 |
} |
1713 |
|
1714 |
static CompletableFuture<Void> asyncRunStage(Executor e, Runnable f) { |
1715 |
if (f == null) throw new NullPointerException(); |
1716 |
CompletableFuture<Void> d = new CompletableFuture<Void>(); |
1717 |
e.execute(new AsyncRun(d, f)); |
1718 |
return d; |
1719 |
} |
1720 |
|
1721 |
/* ------------- Signallers -------------- */ |
1722 |
|
1723 |
/** |
1724 |
* Completion for recording and releasing a waiting thread. This |
1725 |
* class implements ManagedBlocker to avoid starvation when |
1726 |
* blocking actions pile up in ForkJoinPools. |
1727 |
*/ |
1728 |
@SuppressWarnings("serial") |
1729 |
static final class Signaller extends Completion |
1730 |
implements ForkJoinPool.ManagedBlocker { |
1731 |
long nanos; // remaining wait time if timed |
1732 |
final long deadline; // non-zero if timed |
1733 |
final boolean interruptible; |
1734 |
boolean interrupted; |
1735 |
volatile Thread thread; |
1736 |
|
1737 |
Signaller(boolean interruptible, long nanos, long deadline) { |
1738 |
this.thread = Thread.currentThread(); |
1739 |
this.interruptible = interruptible; |
1740 |
this.nanos = nanos; |
1741 |
this.deadline = deadline; |
1742 |
} |
1743 |
final CompletableFuture<?> tryFire(int ignore) { |
1744 |
Thread w; // no need to atomically claim |
1745 |
if ((w = thread) != null) { |
1746 |
thread = null; |
1747 |
LockSupport.unpark(w); |
1748 |
} |
1749 |
return null; |
1750 |
} |
1751 |
public boolean isReleasable() { |
1752 |
if (Thread.interrupted()) |
1753 |
interrupted = true; |
1754 |
return ((interrupted && interruptible) || |
1755 |
(deadline != 0L && |
1756 |
(nanos <= 0L || |
1757 |
(nanos = deadline - System.nanoTime()) <= 0L)) || |
1758 |
thread == null); |
1759 |
} |
1760 |
public boolean block() { |
1761 |
while (!isReleasable()) { |
1762 |
if (deadline == 0L) |
1763 |
LockSupport.park(this); |
1764 |
else |
1765 |
LockSupport.parkNanos(this, nanos); |
1766 |
} |
1767 |
return true; |
1768 |
} |
1769 |
final boolean isLive() { return thread != null; } |
1770 |
} |
1771 |
|
1772 |
/** |
1773 |
* Returns raw result after waiting, or null if interruptible and |
1774 |
* interrupted. |
1775 |
*/ |
1776 |
private Object waitingGet(boolean interruptible) { |
1777 |
Signaller q = null; |
1778 |
boolean queued = false; |
1779 |
Object r; |
1780 |
while ((r = result) == null) { |
1781 |
if (q == null) { |
1782 |
q = new Signaller(interruptible, 0L, 0L); |
1783 |
if (Thread.currentThread() instanceof ForkJoinWorkerThread) |
1784 |
ForkJoinPool.helpAsyncBlocker(defaultExecutor(), q); |
1785 |
} |
1786 |
else if (!queued) |
1787 |
queued = tryPushStack(q); |
1788 |
else { |
1789 |
try { |
1790 |
ForkJoinPool.managedBlock(q); |
1791 |
} catch (InterruptedException ie) { // currently cannot happen |
1792 |
q.interrupted = true; |
1793 |
} |
1794 |
if (q.interrupted && interruptible) |
1795 |
break; |
1796 |
} |
1797 |
} |
1798 |
if (q != null && queued) { |
1799 |
q.thread = null; |
1800 |
if (!interruptible && q.interrupted) |
1801 |
Thread.currentThread().interrupt(); |
1802 |
if (r == null) |
1803 |
cleanStack(); |
1804 |
} |
1805 |
if (r != null || (r = result) != null) |
1806 |
postComplete(); |
1807 |
return r; |
1808 |
} |
1809 |
|
1810 |
/** |
1811 |
* Returns raw result after waiting, or null if interrupted, or |
1812 |
* throws TimeoutException on timeout. |
1813 |
*/ |
1814 |
private Object timedGet(long nanos) throws TimeoutException { |
1815 |
if (Thread.interrupted()) |
1816 |
return null; |
1817 |
if (nanos > 0L) { |
1818 |
long d = System.nanoTime() + nanos; |
1819 |
long deadline = (d == 0L) ? 1L : d; // avoid 0 |
1820 |
Signaller q = null; |
1821 |
boolean queued = false; |
1822 |
Object r; |
1823 |
while ((r = result) == null) { // similar to untimed |
1824 |
if (q == null) { |
1825 |
q = new Signaller(true, nanos, deadline); |
1826 |
if (Thread.currentThread() instanceof ForkJoinWorkerThread) |
1827 |
ForkJoinPool.helpAsyncBlocker(defaultExecutor(), q); |
1828 |
} |
1829 |
else if (!queued) |
1830 |
queued = tryPushStack(q); |
1831 |
else if (q.nanos <= 0L) |
1832 |
break; |
1833 |
else { |
1834 |
try { |
1835 |
ForkJoinPool.managedBlock(q); |
1836 |
} catch (InterruptedException ie) { |
1837 |
q.interrupted = true; |
1838 |
} |
1839 |
if (q.interrupted) |
1840 |
break; |
1841 |
} |
1842 |
} |
1843 |
if (q != null && queued) { |
1844 |
q.thread = null; |
1845 |
if (r == null) |
1846 |
cleanStack(); |
1847 |
} |
1848 |
if (r != null || (r = result) != null) |
1849 |
postComplete(); |
1850 |
if (r != null || (q != null && q.interrupted)) |
1851 |
return r; |
1852 |
} |
1853 |
throw new TimeoutException(); |
1854 |
} |
1855 |
|
1856 |
/* ------------- public methods -------------- */ |
1857 |
|
1858 |
/** |
1859 |
* Creates a new incomplete CompletableFuture. |
1860 |
*/ |
1861 |
public CompletableFuture() { |
1862 |
} |
1863 |
|
1864 |
/** |
1865 |
* Creates a new complete CompletableFuture with given encoded result. |
1866 |
*/ |
1867 |
CompletableFuture(Object r) { |
1868 |
this.result = r; |
1869 |
} |
1870 |
|
1871 |
/** |
1872 |
* Returns a new CompletableFuture that is asynchronously completed |
1873 |
* by a task running in the {@link ForkJoinPool#commonPool()} with |
1874 |
* the value obtained by calling the given Supplier. |
1875 |
* |
1876 |
* @param supplier a function returning the value to be used |
1877 |
* to complete the returned CompletableFuture |
1878 |
* @param <U> the function's return type |
1879 |
* @return the new CompletableFuture |
1880 |
*/ |
1881 |
public static <U> CompletableFuture<U> supplyAsync(Supplier<U> supplier) { |
1882 |
return asyncSupplyStage(ASYNC_POOL, supplier); |
1883 |
} |
1884 |
|
1885 |
/** |
1886 |
* Returns a new CompletableFuture that is asynchronously completed |
1887 |
* by a task running in the given executor with the value obtained |
1888 |
* by calling the given Supplier. |
1889 |
* |
1890 |
* @param supplier a function returning the value to be used |
1891 |
* to complete the returned CompletableFuture |
1892 |
* @param executor the executor to use for asynchronous execution |
1893 |
* @param <U> the function's return type |
1894 |
* @return the new CompletableFuture |
1895 |
*/ |
1896 |
public static <U> CompletableFuture<U> supplyAsync(Supplier<U> supplier, |
1897 |
Executor executor) { |
1898 |
return asyncSupplyStage(screenExecutor(executor), supplier); |
1899 |
} |
1900 |
|
1901 |
/** |
1902 |
* Returns a new CompletableFuture that is asynchronously completed |
1903 |
* by a task running in the {@link ForkJoinPool#commonPool()} after |
1904 |
* it runs the given action. |
1905 |
* |
1906 |
* @param runnable the action to run before completing the |
1907 |
* returned CompletableFuture |
1908 |
* @return the new CompletableFuture |
1909 |
*/ |
1910 |
public static CompletableFuture<Void> runAsync(Runnable runnable) { |
1911 |
return asyncRunStage(ASYNC_POOL, runnable); |
1912 |
} |
1913 |
|
1914 |
/** |
1915 |
* Returns a new CompletableFuture that is asynchronously completed |
1916 |
* by a task running in the given executor after it runs the given |
1917 |
* action. |
1918 |
* |
1919 |
* @param runnable the action to run before completing the |
1920 |
* returned CompletableFuture |
1921 |
* @param executor the executor to use for asynchronous execution |
1922 |
* @return the new CompletableFuture |
1923 |
*/ |
1924 |
public static CompletableFuture<Void> runAsync(Runnable runnable, |
1925 |
Executor executor) { |
1926 |
return asyncRunStage(screenExecutor(executor), runnable); |
1927 |
} |
1928 |
|
1929 |
/** |
1930 |
* Returns a new CompletableFuture that is already completed with |
1931 |
* the given value. |
1932 |
* |
1933 |
* @param value the value |
1934 |
* @param <U> the type of the value |
1935 |
* @return the completed CompletableFuture |
1936 |
*/ |
1937 |
public static <U> CompletableFuture<U> completedFuture(U value) { |
1938 |
return new CompletableFuture<U>((value == null) ? NIL : value); |
1939 |
} |
1940 |
|
1941 |
/** |
1942 |
* Returns {@code true} if completed in any fashion: normally, |
1943 |
* exceptionally, or via cancellation. |
1944 |
* |
1945 |
* @return {@code true} if completed |
1946 |
*/ |
1947 |
public boolean isDone() { |
1948 |
return result != null; |
1949 |
} |
1950 |
|
1951 |
/** |
1952 |
* Waits if necessary for this future to complete, and then |
1953 |
* returns its result. |
1954 |
* |
1955 |
* @return the result value |
1956 |
* @throws CancellationException if this future was cancelled |
1957 |
* @throws ExecutionException if this future completed exceptionally |
1958 |
* @throws InterruptedException if the current thread was interrupted |
1959 |
* while waiting |
1960 |
*/ |
1961 |
@SuppressWarnings("unchecked") |
1962 |
public T get() throws InterruptedException, ExecutionException { |
1963 |
Object r; |
1964 |
if ((r = result) == null) |
1965 |
r = waitingGet(true); |
1966 |
return (T) reportGet(r); |
1967 |
} |
1968 |
|
1969 |
/** |
1970 |
* Waits if necessary for at most the given time for this future |
1971 |
* to complete, and then returns its result, if available. |
1972 |
* |
1973 |
* @param timeout the maximum time to wait |
1974 |
* @param unit the time unit of the timeout argument |
1975 |
* @return the result value |
1976 |
* @throws CancellationException if this future was cancelled |
1977 |
* @throws ExecutionException if this future completed exceptionally |
1978 |
* @throws InterruptedException if the current thread was interrupted |
1979 |
* while waiting |
1980 |
* @throws TimeoutException if the wait timed out |
1981 |
*/ |
1982 |
@SuppressWarnings("unchecked") |
1983 |
public T get(long timeout, TimeUnit unit) |
1984 |
throws InterruptedException, ExecutionException, TimeoutException { |
1985 |
long nanos = unit.toNanos(timeout); |
1986 |
Object r; |
1987 |
if ((r = result) == null) |
1988 |
r = timedGet(nanos); |
1989 |
return (T) reportGet(r); |
1990 |
} |
1991 |
|
1992 |
/** |
1993 |
* Returns the result value when complete, or throws an |
1994 |
* (unchecked) exception if completed exceptionally. To better |
1995 |
* conform with the use of common functional forms, if a |
1996 |
* computation involved in the completion of this |
1997 |
* CompletableFuture threw an exception, this method throws an |
1998 |
* (unchecked) {@link CompletionException} with the underlying |
1999 |
* exception as its cause. |
2000 |
* |
2001 |
* @return the result value |
2002 |
* @throws CancellationException if the computation was cancelled |
2003 |
* @throws CompletionException if this future completed |
2004 |
* exceptionally or a completion computation threw an exception |
2005 |
*/ |
2006 |
@SuppressWarnings("unchecked") |
2007 |
public T join() { |
2008 |
Object r; |
2009 |
if ((r = result) == null) |
2010 |
r = waitingGet(false); |
2011 |
return (T) reportJoin(r); |
2012 |
} |
2013 |
|
2014 |
/** |
2015 |
* Returns the result value (or throws any encountered exception) |
2016 |
* if completed, else returns the given valueIfAbsent. |
2017 |
* |
2018 |
* @param valueIfAbsent the value to return if not completed |
2019 |
* @return the result value, if completed, else the given valueIfAbsent |
2020 |
* @throws CancellationException if the computation was cancelled |
2021 |
* @throws CompletionException if this future completed |
2022 |
* exceptionally or a completion computation threw an exception |
2023 |
*/ |
2024 |
@SuppressWarnings("unchecked") |
2025 |
public T getNow(T valueIfAbsent) { |
2026 |
Object r; |
2027 |
return ((r = result) == null) ? valueIfAbsent : (T) reportJoin(r); |
2028 |
} |
2029 |
|
2030 |
/** |
2031 |
* If not already completed, sets the value returned by {@link |
2032 |
* #get()} and related methods to the given value. |
2033 |
* |
2034 |
* @param value the result value |
2035 |
* @return {@code true} if this invocation caused this CompletableFuture |
2036 |
* to transition to a completed state, else {@code false} |
2037 |
*/ |
2038 |
public boolean complete(T value) { |
2039 |
boolean triggered = completeValue(value); |
2040 |
postComplete(); |
2041 |
return triggered; |
2042 |
} |
2043 |
|
2044 |
/** |
2045 |
* If not already completed, causes invocations of {@link #get()} |
2046 |
* and related methods to throw the given exception. |
2047 |
* |
2048 |
* @param ex the exception |
2049 |
* @return {@code true} if this invocation caused this CompletableFuture |
2050 |
* to transition to a completed state, else {@code false} |
2051 |
*/ |
2052 |
public boolean completeExceptionally(Throwable ex) { |
2053 |
if (ex == null) throw new NullPointerException(); |
2054 |
boolean triggered = internalComplete(new AltResult(ex)); |
2055 |
postComplete(); |
2056 |
return triggered; |
2057 |
} |
2058 |
|
2059 |
public <U> CompletableFuture<U> thenApply( |
2060 |
Function<? super T,? extends U> fn) { |
2061 |
return uniApplyStage(null, fn); |
2062 |
} |
2063 |
|
2064 |
public <U> CompletableFuture<U> thenApplyAsync( |
2065 |
Function<? super T,? extends U> fn) { |
2066 |
return uniApplyStage(defaultExecutor(), fn); |
2067 |
} |
2068 |
|
2069 |
public <U> CompletableFuture<U> thenApplyAsync( |
2070 |
Function<? super T,? extends U> fn, Executor executor) { |
2071 |
return uniApplyStage(screenExecutor(executor), fn); |
2072 |
} |
2073 |
|
2074 |
public CompletableFuture<Void> thenAccept(Consumer<? super T> action) { |
2075 |
return uniAcceptStage(null, action); |
2076 |
} |
2077 |
|
2078 |
public CompletableFuture<Void> thenAcceptAsync(Consumer<? super T> action) { |
2079 |
return uniAcceptStage(defaultExecutor(), action); |
2080 |
} |
2081 |
|
2082 |
public CompletableFuture<Void> thenAcceptAsync(Consumer<? super T> action, |
2083 |
Executor executor) { |
2084 |
return uniAcceptStage(screenExecutor(executor), action); |
2085 |
} |
2086 |
|
2087 |
public CompletableFuture<Void> thenRun(Runnable action) { |
2088 |
return uniRunStage(null, action); |
2089 |
} |
2090 |
|
2091 |
public CompletableFuture<Void> thenRunAsync(Runnable action) { |
2092 |
return uniRunStage(defaultExecutor(), action); |
2093 |
} |
2094 |
|
2095 |
public CompletableFuture<Void> thenRunAsync(Runnable action, |
2096 |
Executor executor) { |
2097 |
return uniRunStage(screenExecutor(executor), action); |
2098 |
} |
2099 |
|
2100 |
public <U,V> CompletableFuture<V> thenCombine( |
2101 |
CompletionStage<? extends U> other, |
2102 |
BiFunction<? super T,? super U,? extends V> fn) { |
2103 |
return biApplyStage(null, other, fn); |
2104 |
} |
2105 |
|
2106 |
public <U,V> CompletableFuture<V> thenCombineAsync( |
2107 |
CompletionStage<? extends U> other, |
2108 |
BiFunction<? super T,? super U,? extends V> fn) { |
2109 |
return biApplyStage(defaultExecutor(), other, fn); |
2110 |
} |
2111 |
|
2112 |
public <U,V> CompletableFuture<V> thenCombineAsync( |
2113 |
CompletionStage<? extends U> other, |
2114 |
BiFunction<? super T,? super U,? extends V> fn, Executor executor) { |
2115 |
return biApplyStage(screenExecutor(executor), other, fn); |
2116 |
} |
2117 |
|
2118 |
public <U> CompletableFuture<Void> thenAcceptBoth( |
2119 |
CompletionStage<? extends U> other, |
2120 |
BiConsumer<? super T, ? super U> action) { |
2121 |
return biAcceptStage(null, other, action); |
2122 |
} |
2123 |
|
2124 |
public <U> CompletableFuture<Void> thenAcceptBothAsync( |
2125 |
CompletionStage<? extends U> other, |
2126 |
BiConsumer<? super T, ? super U> action) { |
2127 |
return biAcceptStage(defaultExecutor(), other, action); |
2128 |
} |
2129 |
|
2130 |
public <U> CompletableFuture<Void> thenAcceptBothAsync( |
2131 |
CompletionStage<? extends U> other, |
2132 |
BiConsumer<? super T, ? super U> action, Executor executor) { |
2133 |
return biAcceptStage(screenExecutor(executor), other, action); |
2134 |
} |
2135 |
|
2136 |
public CompletableFuture<Void> runAfterBoth(CompletionStage<?> other, |
2137 |
Runnable action) { |
2138 |
return biRunStage(null, other, action); |
2139 |
} |
2140 |
|
2141 |
public CompletableFuture<Void> runAfterBothAsync(CompletionStage<?> other, |
2142 |
Runnable action) { |
2143 |
return biRunStage(defaultExecutor(), other, action); |
2144 |
} |
2145 |
|
2146 |
public CompletableFuture<Void> runAfterBothAsync(CompletionStage<?> other, |
2147 |
Runnable action, |
2148 |
Executor executor) { |
2149 |
return biRunStage(screenExecutor(executor), other, action); |
2150 |
} |
2151 |
|
2152 |
public <U> CompletableFuture<U> applyToEither( |
2153 |
CompletionStage<? extends T> other, Function<? super T, U> fn) { |
2154 |
return orApplyStage(null, other, fn); |
2155 |
} |
2156 |
|
2157 |
public <U> CompletableFuture<U> applyToEitherAsync( |
2158 |
CompletionStage<? extends T> other, Function<? super T, U> fn) { |
2159 |
return orApplyStage(defaultExecutor(), other, fn); |
2160 |
} |
2161 |
|
2162 |
public <U> CompletableFuture<U> applyToEitherAsync( |
2163 |
CompletionStage<? extends T> other, Function<? super T, U> fn, |
2164 |
Executor executor) { |
2165 |
return orApplyStage(screenExecutor(executor), other, fn); |
2166 |
} |
2167 |
|
2168 |
public CompletableFuture<Void> acceptEither( |
2169 |
CompletionStage<? extends T> other, Consumer<? super T> action) { |
2170 |
return orAcceptStage(null, other, action); |
2171 |
} |
2172 |
|
2173 |
public CompletableFuture<Void> acceptEitherAsync( |
2174 |
CompletionStage<? extends T> other, Consumer<? super T> action) { |
2175 |
return orAcceptStage(defaultExecutor(), other, action); |
2176 |
} |
2177 |
|
2178 |
public CompletableFuture<Void> acceptEitherAsync( |
2179 |
CompletionStage<? extends T> other, Consumer<? super T> action, |
2180 |
Executor executor) { |
2181 |
return orAcceptStage(screenExecutor(executor), other, action); |
2182 |
} |
2183 |
|
2184 |
public CompletableFuture<Void> runAfterEither(CompletionStage<?> other, |
2185 |
Runnable action) { |
2186 |
return orRunStage(null, other, action); |
2187 |
} |
2188 |
|
2189 |
public CompletableFuture<Void> runAfterEitherAsync(CompletionStage<?> other, |
2190 |
Runnable action) { |
2191 |
return orRunStage(defaultExecutor(), other, action); |
2192 |
} |
2193 |
|
2194 |
public CompletableFuture<Void> runAfterEitherAsync(CompletionStage<?> other, |
2195 |
Runnable action, |
2196 |
Executor executor) { |
2197 |
return orRunStage(screenExecutor(executor), other, action); |
2198 |
} |
2199 |
|
2200 |
public <U> CompletableFuture<U> thenCompose( |
2201 |
Function<? super T, ? extends CompletionStage<U>> fn) { |
2202 |
return uniComposeStage(null, fn); |
2203 |
} |
2204 |
|
2205 |
public <U> CompletableFuture<U> thenComposeAsync( |
2206 |
Function<? super T, ? extends CompletionStage<U>> fn) { |
2207 |
return uniComposeStage(defaultExecutor(), fn); |
2208 |
} |
2209 |
|
2210 |
public <U> CompletableFuture<U> thenComposeAsync( |
2211 |
Function<? super T, ? extends CompletionStage<U>> fn, |
2212 |
Executor executor) { |
2213 |
return uniComposeStage(screenExecutor(executor), fn); |
2214 |
} |
2215 |
|
2216 |
public CompletableFuture<T> whenComplete( |
2217 |
BiConsumer<? super T, ? super Throwable> action) { |
2218 |
return uniWhenCompleteStage(null, action); |
2219 |
} |
2220 |
|
2221 |
public CompletableFuture<T> whenCompleteAsync( |
2222 |
BiConsumer<? super T, ? super Throwable> action) { |
2223 |
return uniWhenCompleteStage(defaultExecutor(), action); |
2224 |
} |
2225 |
|
2226 |
public CompletableFuture<T> whenCompleteAsync( |
2227 |
BiConsumer<? super T, ? super Throwable> action, Executor executor) { |
2228 |
return uniWhenCompleteStage(screenExecutor(executor), action); |
2229 |
} |
2230 |
|
2231 |
public <U> CompletableFuture<U> handle( |
2232 |
BiFunction<? super T, Throwable, ? extends U> fn) { |
2233 |
return uniHandleStage(null, fn); |
2234 |
} |
2235 |
|
2236 |
public <U> CompletableFuture<U> handleAsync( |
2237 |
BiFunction<? super T, Throwable, ? extends U> fn) { |
2238 |
return uniHandleStage(defaultExecutor(), fn); |
2239 |
} |
2240 |
|
2241 |
public <U> CompletableFuture<U> handleAsync( |
2242 |
BiFunction<? super T, Throwable, ? extends U> fn, Executor executor) { |
2243 |
return uniHandleStage(screenExecutor(executor), fn); |
2244 |
} |
2245 |
|
2246 |
/** |
2247 |
* Returns this CompletableFuture. |
2248 |
* |
2249 |
* @return this CompletableFuture |
2250 |
*/ |
2251 |
public CompletableFuture<T> toCompletableFuture() { |
2252 |
return this; |
2253 |
} |
2254 |
|
2255 |
// not in interface CompletionStage |
2256 |
|
2257 |
/** |
2258 |
* Returns a new CompletableFuture that is completed when this |
2259 |
* CompletableFuture completes, with the result of the given |
2260 |
* function of the exception triggering this CompletableFuture's |
2261 |
* completion when it completes exceptionally; otherwise, if this |
2262 |
* CompletableFuture completes normally, then the returned |
2263 |
* CompletableFuture also completes normally with the same value. |
2264 |
* Note: More flexible versions of this functionality are |
2265 |
* available using methods {@code whenComplete} and {@code handle}. |
2266 |
* |
2267 |
* @param fn the function to use to compute the value of the |
2268 |
* returned CompletableFuture if this CompletableFuture completed |
2269 |
* exceptionally |
2270 |
* @return the new CompletableFuture |
2271 |
*/ |
2272 |
public CompletableFuture<T> exceptionally( |
2273 |
Function<Throwable, ? extends T> fn) { |
2274 |
return uniExceptionallyStage(fn); |
2275 |
} |
2276 |
|
2277 |
|
2278 |
/* ------------- Arbitrary-arity constructions -------------- */ |
2279 |
|
2280 |
/** |
2281 |
* Returns a new CompletableFuture that is completed when all of |
2282 |
* the given CompletableFutures complete. If any of the given |
2283 |
* CompletableFutures complete exceptionally, then the returned |
2284 |
* CompletableFuture also does so, with a CompletionException |
2285 |
* holding this exception as its cause. Otherwise, the results, |
2286 |
* if any, of the given CompletableFutures are not reflected in |
2287 |
* the returned CompletableFuture, but may be obtained by |
2288 |
* inspecting them individually. If no CompletableFutures are |
2289 |
* provided, returns a CompletableFuture completed with the value |
2290 |
* {@code null}. |
2291 |
* |
2292 |
* <p>Among the applications of this method is to await completion |
2293 |
* of a set of independent CompletableFutures before continuing a |
2294 |
* program, as in: {@code CompletableFuture.allOf(c1, c2, |
2295 |
* c3).join();}. |
2296 |
* |
2297 |
* @param cfs the CompletableFutures |
2298 |
* @return a new CompletableFuture that is completed when all of the |
2299 |
* given CompletableFutures complete |
2300 |
* @throws NullPointerException if the array or any of its elements are |
2301 |
* {@code null} |
2302 |
*/ |
2303 |
public static CompletableFuture<Void> allOf(CompletableFuture<?>... cfs) { |
2304 |
return andTree(cfs, 0, cfs.length - 1); |
2305 |
} |
2306 |
|
2307 |
/** |
2308 |
* Returns a new CompletableFuture that is completed when any of |
2309 |
* the given CompletableFutures complete, with the same result. |
2310 |
* Otherwise, if it completed exceptionally, the returned |
2311 |
* CompletableFuture also does so, with a CompletionException |
2312 |
* holding this exception as its cause. If no CompletableFutures |
2313 |
* are provided, returns an incomplete CompletableFuture. |
2314 |
* |
2315 |
* @param cfs the CompletableFutures |
2316 |
* @return a new CompletableFuture that is completed with the |
2317 |
* result or exception of any of the given CompletableFutures when |
2318 |
* one completes |
2319 |
* @throws NullPointerException if the array or any of its elements are |
2320 |
* {@code null} |
2321 |
*/ |
2322 |
public static CompletableFuture<Object> anyOf(CompletableFuture<?>... cfs) { |
2323 |
return orTree(cfs, 0, cfs.length - 1); |
2324 |
} |
2325 |
|
2326 |
/* ------------- Control and status methods -------------- */ |
2327 |
|
2328 |
/** |
2329 |
* If not already completed, completes this CompletableFuture with |
2330 |
* a {@link CancellationException}. Dependent CompletableFutures |
2331 |
* that have not already completed will also complete |
2332 |
* exceptionally, with a {@link CompletionException} caused by |
2333 |
* this {@code CancellationException}. |
2334 |
* |
2335 |
* @param mayInterruptIfRunning this value has no effect in this |
2336 |
* implementation because interrupts are not used to control |
2337 |
* processing. |
2338 |
* |
2339 |
* @return {@code true} if this task is now cancelled |
2340 |
*/ |
2341 |
public boolean cancel(boolean mayInterruptIfRunning) { |
2342 |
boolean cancelled = (result == null) && |
2343 |
internalComplete(new AltResult(new CancellationException())); |
2344 |
postComplete(); |
2345 |
return cancelled || isCancelled(); |
2346 |
} |
2347 |
|
2348 |
/** |
2349 |
* Returns {@code true} if this CompletableFuture was cancelled |
2350 |
* before it completed normally. |
2351 |
* |
2352 |
* @return {@code true} if this CompletableFuture was cancelled |
2353 |
* before it completed normally |
2354 |
*/ |
2355 |
public boolean isCancelled() { |
2356 |
Object r; |
2357 |
return ((r = result) instanceof AltResult) && |
2358 |
(((AltResult)r).ex instanceof CancellationException); |
2359 |
} |
2360 |
|
2361 |
/** |
2362 |
* Returns {@code true} if this CompletableFuture completed |
2363 |
* exceptionally, in any way. Possible causes include |
2364 |
* cancellation, explicit invocation of {@code |
2365 |
* completeExceptionally}, and abrupt termination of a |
2366 |
* CompletionStage action. |
2367 |
* |
2368 |
* @return {@code true} if this CompletableFuture completed |
2369 |
* exceptionally |
2370 |
*/ |
2371 |
public boolean isCompletedExceptionally() { |
2372 |
Object r; |
2373 |
return ((r = result) instanceof AltResult) && r != NIL; |
2374 |
} |
2375 |
|
2376 |
/** |
2377 |
* Forcibly sets or resets the value subsequently returned by |
2378 |
* method {@link #get()} and related methods, whether or not |
2379 |
* already completed. This method is designed for use only in |
2380 |
* error recovery actions, and even in such situations may result |
2381 |
* in ongoing dependent completions using established versus |
2382 |
* overwritten outcomes. |
2383 |
* |
2384 |
* @param value the completion value |
2385 |
*/ |
2386 |
public void obtrudeValue(T value) { |
2387 |
result = (value == null) ? NIL : value; |
2388 |
postComplete(); |
2389 |
} |
2390 |
|
2391 |
/** |
2392 |
* Forcibly causes subsequent invocations of method {@link #get()} |
2393 |
* and related methods to throw the given exception, whether or |
2394 |
* not already completed. This method is designed for use only in |
2395 |
* error recovery actions, and even in such situations may result |
2396 |
* in ongoing dependent completions using established versus |
2397 |
* overwritten outcomes. |
2398 |
* |
2399 |
* @param ex the exception |
2400 |
* @throws NullPointerException if the exception is null |
2401 |
*/ |
2402 |
public void obtrudeException(Throwable ex) { |
2403 |
if (ex == null) throw new NullPointerException(); |
2404 |
result = new AltResult(ex); |
2405 |
postComplete(); |
2406 |
} |
2407 |
|
2408 |
/** |
2409 |
* Returns the estimated number of CompletableFutures whose |
2410 |
* completions are awaiting completion of this CompletableFuture. |
2411 |
* This method is designed for use in monitoring system state, not |
2412 |
* for synchronization control. |
2413 |
* |
2414 |
* @return the number of dependent CompletableFutures |
2415 |
*/ |
2416 |
public int getNumberOfDependents() { |
2417 |
int count = 0; |
2418 |
for (Completion p = stack; p != null; p = p.next) |
2419 |
++count; |
2420 |
return count; |
2421 |
} |
2422 |
|
2423 |
/** |
2424 |
* Returns a string identifying this CompletableFuture, as well as |
2425 |
* its completion state. The state, in brackets, contains the |
2426 |
* String {@code "Completed Normally"} or the String {@code |
2427 |
* "Completed Exceptionally"}, or the String {@code "Not |
2428 |
* completed"} followed by the number of CompletableFutures |
2429 |
* dependent upon its completion, if any. |
2430 |
* |
2431 |
* @return a string identifying this CompletableFuture, as well as its state |
2432 |
*/ |
2433 |
public String toString() { |
2434 |
Object r = result; |
2435 |
int count = 0; // avoid call to getNumberOfDependents in case disabled |
2436 |
for (Completion p = stack; p != null; p = p.next) |
2437 |
++count; |
2438 |
return super.toString() + |
2439 |
((r == null) ? |
2440 |
((count == 0) ? |
2441 |
"[Not completed]" : |
2442 |
"[Not completed, " + count + " dependents]") : |
2443 |
(((r instanceof AltResult) && ((AltResult)r).ex != null) ? |
2444 |
"[Completed exceptionally]" : |
2445 |
"[Completed normally]")); |
2446 |
} |
2447 |
|
2448 |
// jdk9 additions |
2449 |
|
2450 |
/** |
2451 |
* Returns a new incomplete CompletableFuture of the type to be |
2452 |
* returned by a CompletionStage method. Subclasses should |
2453 |
* normally override this method to return an instance of the same |
2454 |
* class as this CompletableFuture. The default implementation |
2455 |
* returns an instance of class CompletableFuture. |
2456 |
* |
2457 |
* @param <U> the type of the value |
2458 |
* @return a new CompletableFuture |
2459 |
* @since 9 |
2460 |
*/ |
2461 |
public <U> CompletableFuture<U> newIncompleteFuture() { |
2462 |
return new CompletableFuture<U>(); |
2463 |
} |
2464 |
|
2465 |
/** |
2466 |
* Returns the default Executor used for async methods that do not |
2467 |
* specify an Executor. This class uses the {@link |
2468 |
* ForkJoinPool#commonPool()} if it supports more than one |
2469 |
* parallel thread, or else an Executor using one thread per async |
2470 |
* task. This method may be overridden in subclasses to return |
2471 |
* an Executor that provides at least one independent thread. |
2472 |
* |
2473 |
* @return the executor |
2474 |
* @since 9 |
2475 |
*/ |
2476 |
public Executor defaultExecutor() { |
2477 |
return ASYNC_POOL; |
2478 |
} |
2479 |
|
2480 |
/** |
2481 |
* Returns a new CompletableFuture that is completed normally with |
2482 |
* the same value as this CompletableFuture when it completes |
2483 |
* normally. If this CompletableFuture completes exceptionally, |
2484 |
* then the returned CompletableFuture completes exceptionally |
2485 |
* with a CompletionException with this exception as cause. The |
2486 |
* behavior is equivalent to {@code thenApply(x -> x)}. This |
2487 |
* method may be useful as a form of "defensive copying", to |
2488 |
* prevent clients from completing, while still being able to |
2489 |
* arrange dependent actions. |
2490 |
* |
2491 |
* @return the new CompletableFuture |
2492 |
* @since 9 |
2493 |
*/ |
2494 |
public CompletableFuture<T> copy() { |
2495 |
return uniCopyStage(); |
2496 |
} |
2497 |
|
2498 |
/** |
2499 |
* Returns a new CompletionStage that is completed normally with |
2500 |
* the same value as this CompletableFuture when it completes |
2501 |
* normally, and cannot be independently completed or otherwise |
2502 |
* used in ways not defined by the methods of interface {@link |
2503 |
* CompletionStage}. If this CompletableFuture completes |
2504 |
* exceptionally, then the returned CompletionStage completes |
2505 |
* exceptionally with a CompletionException with this exception as |
2506 |
* cause. |
2507 |
* |
2508 |
* @return the new CompletionStage |
2509 |
* @since 9 |
2510 |
*/ |
2511 |
public CompletionStage<T> minimalCompletionStage() { |
2512 |
return uniAsMinimalStage(); |
2513 |
} |
2514 |
|
2515 |
/** |
2516 |
* Completes this CompletableFuture with the result of |
2517 |
* the given Supplier function invoked from an asynchronous |
2518 |
* task using the given executor. |
2519 |
* |
2520 |
* @param supplier a function returning the value to be used |
2521 |
* to complete this CompletableFuture |
2522 |
* @param executor the executor to use for asynchronous execution |
2523 |
* @return this CompletableFuture |
2524 |
* @since 9 |
2525 |
*/ |
2526 |
public CompletableFuture<T> completeAsync(Supplier<? extends T> supplier, |
2527 |
Executor executor) { |
2528 |
if (supplier == null || executor == null) |
2529 |
throw new NullPointerException(); |
2530 |
executor.execute(new AsyncSupply<T>(this, supplier)); |
2531 |
return this; |
2532 |
} |
2533 |
|
2534 |
/** |
2535 |
* Completes this CompletableFuture with the result of the given |
2536 |
* Supplier function invoked from an asynchronous task using the |
2537 |
* default executor. |
2538 |
* |
2539 |
* @param supplier a function returning the value to be used |
2540 |
* to complete this CompletableFuture |
2541 |
* @return this CompletableFuture |
2542 |
* @since 9 |
2543 |
*/ |
2544 |
public CompletableFuture<T> completeAsync(Supplier<? extends T> supplier) { |
2545 |
return completeAsync(supplier, defaultExecutor()); |
2546 |
} |
2547 |
|
2548 |
/** |
2549 |
* Exceptionally completes this CompletableFuture with |
2550 |
* a {@link TimeoutException} if not otherwise completed |
2551 |
* before the given timeout. |
2552 |
* |
2553 |
* @param timeout how long to wait before completing exceptionally |
2554 |
* with a TimeoutException, in units of {@code unit} |
2555 |
* @param unit a {@code TimeUnit} determining how to interpret the |
2556 |
* {@code timeout} parameter |
2557 |
* @return this CompletableFuture |
2558 |
* @since 9 |
2559 |
*/ |
2560 |
public CompletableFuture<T> orTimeout(long timeout, TimeUnit unit) { |
2561 |
if (unit == null) |
2562 |
throw new NullPointerException(); |
2563 |
if (result == null) |
2564 |
whenComplete(new Canceller(Delayer.delay(new Timeout(this), |
2565 |
timeout, unit))); |
2566 |
return this; |
2567 |
} |
2568 |
|
2569 |
/** |
2570 |
* Completes this CompletableFuture with the given value if not |
2571 |
* otherwise completed before the given timeout. |
2572 |
* |
2573 |
* @param value the value to use upon timeout |
2574 |
* @param timeout how long to wait before completing normally |
2575 |
* with the given value, in units of {@code unit} |
2576 |
* @param unit a {@code TimeUnit} determining how to interpret the |
2577 |
* {@code timeout} parameter |
2578 |
* @return this CompletableFuture |
2579 |
* @since 9 |
2580 |
*/ |
2581 |
public CompletableFuture<T> completeOnTimeout(T value, long timeout, |
2582 |
TimeUnit unit) { |
2583 |
if (unit == null) |
2584 |
throw new NullPointerException(); |
2585 |
if (result == null) |
2586 |
whenComplete(new Canceller(Delayer.delay( |
2587 |
new DelayedCompleter<T>(this, value), |
2588 |
timeout, unit))); |
2589 |
return this; |
2590 |
} |
2591 |
|
2592 |
/** |
2593 |
* Returns a new Executor that submits a task to the given base |
2594 |
* executor after the given delay (or no delay if non-positive). |
2595 |
* Each delay commences upon invocation of the returned executor's |
2596 |
* {@code execute} method. |
2597 |
* |
2598 |
* @param delay how long to delay, in units of {@code unit} |
2599 |
* @param unit a {@code TimeUnit} determining how to interpret the |
2600 |
* {@code delay} parameter |
2601 |
* @param executor the base executor |
2602 |
* @return the new delayed executor |
2603 |
* @since 9 |
2604 |
*/ |
2605 |
public static Executor delayedExecutor(long delay, TimeUnit unit, |
2606 |
Executor executor) { |
2607 |
if (unit == null || executor == null) |
2608 |
throw new NullPointerException(); |
2609 |
return new DelayedExecutor(delay, unit, executor); |
2610 |
} |
2611 |
|
2612 |
/** |
2613 |
* Returns a new Executor that submits a task to the default |
2614 |
* executor after the given delay (or no delay if non-positive). |
2615 |
* Each delay commences upon invocation of the returned executor's |
2616 |
* {@code execute} method. |
2617 |
* |
2618 |
* @param delay how long to delay, in units of {@code unit} |
2619 |
* @param unit a {@code TimeUnit} determining how to interpret the |
2620 |
* {@code delay} parameter |
2621 |
* @return the new delayed executor |
2622 |
* @since 9 |
2623 |
*/ |
2624 |
public static Executor delayedExecutor(long delay, TimeUnit unit) { |
2625 |
if (unit == null) |
2626 |
throw new NullPointerException(); |
2627 |
return new DelayedExecutor(delay, unit, ASYNC_POOL); |
2628 |
} |
2629 |
|
2630 |
/** |
2631 |
* Returns a new CompletionStage that is already completed with |
2632 |
* the given value and supports only those methods in |
2633 |
* interface {@link CompletionStage}. |
2634 |
* |
2635 |
* @param value the value |
2636 |
* @param <U> the type of the value |
2637 |
* @return the completed CompletionStage |
2638 |
* @since 9 |
2639 |
*/ |
2640 |
public static <U> CompletionStage<U> completedStage(U value) { |
2641 |
return new MinimalStage<U>((value == null) ? NIL : value); |
2642 |
} |
2643 |
|
2644 |
/** |
2645 |
* Returns a new CompletableFuture that is already completed |
2646 |
* exceptionally with the given exception. |
2647 |
* |
2648 |
* @param ex the exception |
2649 |
* @param <U> the type of the value |
2650 |
* @return the exceptionally completed CompletableFuture |
2651 |
* @since 9 |
2652 |
*/ |
2653 |
public static <U> CompletableFuture<U> failedFuture(Throwable ex) { |
2654 |
if (ex == null) throw new NullPointerException(); |
2655 |
return new CompletableFuture<U>(new AltResult(ex)); |
2656 |
} |
2657 |
|
2658 |
/** |
2659 |
* Returns a new CompletionStage that is already completed |
2660 |
* exceptionally with the given exception and supports only those |
2661 |
* methods in interface {@link CompletionStage}. |
2662 |
* |
2663 |
* @param ex the exception |
2664 |
* @param <U> the type of the value |
2665 |
* @return the exceptionally completed CompletionStage |
2666 |
* @since 9 |
2667 |
*/ |
2668 |
public static <U> CompletionStage<U> failedStage(Throwable ex) { |
2669 |
if (ex == null) throw new NullPointerException(); |
2670 |
return new MinimalStage<U>(new AltResult(ex)); |
2671 |
} |
2672 |
|
2673 |
/** |
2674 |
* Singleton delay scheduler, used only for starting and |
2675 |
* cancelling tasks. |
2676 |
*/ |
2677 |
static final class Delayer { |
2678 |
static ScheduledFuture<?> delay(Runnable command, long delay, |
2679 |
TimeUnit unit) { |
2680 |
return delayer.schedule(command, delay, unit); |
2681 |
} |
2682 |
|
2683 |
static final class DaemonThreadFactory implements ThreadFactory { |
2684 |
public Thread newThread(Runnable r) { |
2685 |
Thread t = new Thread(r); |
2686 |
t.setDaemon(true); |
2687 |
t.setName("CompletableFutureDelayScheduler"); |
2688 |
return t; |
2689 |
} |
2690 |
} |
2691 |
|
2692 |
static final ScheduledThreadPoolExecutor delayer; |
2693 |
static { |
2694 |
(delayer = new ScheduledThreadPoolExecutor( |
2695 |
1, new DaemonThreadFactory())). |
2696 |
setRemoveOnCancelPolicy(true); |
2697 |
} |
2698 |
} |
2699 |
|
2700 |
// Little class-ified lambdas to better support monitoring |
2701 |
|
2702 |
static final class DelayedExecutor implements Executor { |
2703 |
final long delay; |
2704 |
final TimeUnit unit; |
2705 |
final Executor executor; |
2706 |
DelayedExecutor(long delay, TimeUnit unit, Executor executor) { |
2707 |
this.delay = delay; this.unit = unit; this.executor = executor; |
2708 |
} |
2709 |
public void execute(Runnable r) { |
2710 |
Delayer.delay(new TaskSubmitter(executor, r), delay, unit); |
2711 |
} |
2712 |
} |
2713 |
|
2714 |
/** Action to submit user task */ |
2715 |
static final class TaskSubmitter implements Runnable { |
2716 |
final Executor executor; |
2717 |
final Runnable action; |
2718 |
TaskSubmitter(Executor executor, Runnable action) { |
2719 |
this.executor = executor; |
2720 |
this.action = action; |
2721 |
} |
2722 |
public void run() { executor.execute(action); } |
2723 |
} |
2724 |
|
2725 |
/** Action to completeExceptionally on timeout */ |
2726 |
static final class Timeout implements Runnable { |
2727 |
final CompletableFuture<?> f; |
2728 |
Timeout(CompletableFuture<?> f) { this.f = f; } |
2729 |
public void run() { |
2730 |
if (f != null && !f.isDone()) |
2731 |
f.completeExceptionally(new TimeoutException()); |
2732 |
} |
2733 |
} |
2734 |
|
2735 |
/** Action to complete on timeout */ |
2736 |
static final class DelayedCompleter<U> implements Runnable { |
2737 |
final CompletableFuture<U> f; |
2738 |
final U u; |
2739 |
DelayedCompleter(CompletableFuture<U> f, U u) { this.f = f; this.u = u; } |
2740 |
public void run() { |
2741 |
if (f != null) |
2742 |
f.complete(u); |
2743 |
} |
2744 |
} |
2745 |
|
2746 |
/** Action to cancel unneeded timeouts */ |
2747 |
static final class Canceller implements BiConsumer<Object, Throwable> { |
2748 |
final Future<?> f; |
2749 |
Canceller(Future<?> f) { this.f = f; } |
2750 |
public void accept(Object ignore, Throwable ex) { |
2751 |
if (ex == null && f != null && !f.isDone()) |
2752 |
f.cancel(false); |
2753 |
} |
2754 |
} |
2755 |
|
2756 |
/** |
2757 |
* A subclass that just throws UOE for most non-CompletionStage methods. |
2758 |
*/ |
2759 |
static final class MinimalStage<T> extends CompletableFuture<T> { |
2760 |
MinimalStage() { } |
2761 |
MinimalStage(Object r) { super(r); } |
2762 |
@Override public <U> CompletableFuture<U> newIncompleteFuture() { |
2763 |
return new MinimalStage<U>(); } |
2764 |
@Override public T get() { |
2765 |
throw new UnsupportedOperationException(); } |
2766 |
@Override public T get(long timeout, TimeUnit unit) { |
2767 |
throw new UnsupportedOperationException(); } |
2768 |
@Override public T getNow(T valueIfAbsent) { |
2769 |
throw new UnsupportedOperationException(); } |
2770 |
@Override public T join() { |
2771 |
throw new UnsupportedOperationException(); } |
2772 |
@Override public boolean complete(T value) { |
2773 |
throw new UnsupportedOperationException(); } |
2774 |
@Override public boolean completeExceptionally(Throwable ex) { |
2775 |
throw new UnsupportedOperationException(); } |
2776 |
@Override public boolean cancel(boolean mayInterruptIfRunning) { |
2777 |
throw new UnsupportedOperationException(); } |
2778 |
@Override public void obtrudeValue(T value) { |
2779 |
throw new UnsupportedOperationException(); } |
2780 |
@Override public void obtrudeException(Throwable ex) { |
2781 |
throw new UnsupportedOperationException(); } |
2782 |
@Override public boolean isDone() { |
2783 |
throw new UnsupportedOperationException(); } |
2784 |
@Override public boolean isCancelled() { |
2785 |
throw new UnsupportedOperationException(); } |
2786 |
@Override public boolean isCompletedExceptionally() { |
2787 |
throw new UnsupportedOperationException(); } |
2788 |
@Override public int getNumberOfDependents() { |
2789 |
throw new UnsupportedOperationException(); } |
2790 |
@Override public CompletableFuture<T> completeAsync |
2791 |
(Supplier<? extends T> supplier, Executor executor) { |
2792 |
throw new UnsupportedOperationException(); } |
2793 |
@Override public CompletableFuture<T> completeAsync |
2794 |
(Supplier<? extends T> supplier) { |
2795 |
throw new UnsupportedOperationException(); } |
2796 |
@Override public CompletableFuture<T> orTimeout |
2797 |
(long timeout, TimeUnit unit) { |
2798 |
throw new UnsupportedOperationException(); } |
2799 |
@Override public CompletableFuture<T> completeOnTimeout |
2800 |
(T value, long timeout, TimeUnit unit) { |
2801 |
throw new UnsupportedOperationException(); } |
2802 |
} |
2803 |
|
2804 |
// VarHandle mechanics |
2805 |
private static final VarHandle RESULT; |
2806 |
private static final VarHandle STACK; |
2807 |
private static final VarHandle NEXT; |
2808 |
static { |
2809 |
try { |
2810 |
MethodHandles.Lookup l = MethodHandles.lookup(); |
2811 |
RESULT = l.findVarHandle(CompletableFuture.class, "result", Object.class); |
2812 |
STACK = l.findVarHandle(CompletableFuture.class, "stack", Completion.class); |
2813 |
NEXT = l.findVarHandle(Completion.class, "next", Completion.class); |
2814 |
} catch (ReflectiveOperationException e) { |
2815 |
throw new Error(e); |
2816 |
} |
2817 |
|
2818 |
// Reduce the risk of rare disastrous classloading in first call to |
2819 |
// LockSupport.park: https://bugs.openjdk.java.net/browse/JDK-8074773 |
2820 |
Class<?> ensureLoaded = LockSupport.class; |
2821 |
} |
2822 |
} |