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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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import java.util.function.Supplier; |
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import java.util.function.Consumer; |
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import java.util.function.BiConsumer; |
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import java.util.function.Function; |
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import java.util.function.BiFunction; |
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import java.util.concurrent.Future; |
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import java.util.concurrent.TimeUnit; |
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import java.util.concurrent.ForkJoinPool; |
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import java.util.concurrent.ForkJoinTask; |
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import java.util.concurrent.Executor; |
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import java.util.concurrent.ThreadLocalRandom; |
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import java.util.concurrent.ExecutionException; |
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import java.util.concurrent.TimeoutException; |
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import java.util.concurrent.CancellationException; |
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import java.util.concurrent.CompletionException; |
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import java.util.concurrent.CompletionStage; |
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import java.util.concurrent.locks.LockSupport; |
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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.</li> |
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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). To simplify |
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* monitoring, debugging, and tracking, all generated asynchronous |
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* tasks are instances of the marker interface {@link |
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* AsynchronousCompletionTask}. </li> |
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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. </li> </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.</li> |
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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.</li> </ul> |
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* |
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* @author Doug Lea |
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* @since 1.8 |
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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 field result (set via CAS) indicates done. An |
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* AltResult is used to box null as a result, as well as to hold |
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* exceptions. Using a single field makes completion simple to |
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* detect and trigger. Encoding and decoding is straightforward |
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* but adds to the sprawl of trapping and associating exceptions |
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* with targets. Minor simplifications rely on (static) NIL (to |
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* box null results) being the only AltResult with a null |
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* exception field, so we don't usually need explicit comparisons. |
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* Even though some of the generics casts are unchecked (see |
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* SuppressWarnings annotations), they are placed to be |
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* 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 single-input |
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* (UniCompletion), two-input (BiCompletion), projected |
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* (BiCompletions using either (not both) of two inputs), shared |
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* (CoCompletion, used by the second of two sources), zero-input |
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* source actions, and Signallers that unblock waiters. Class |
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* 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 adaptors in common usages. We also |
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* include "Relay" classes/methods that don't correspond to user |
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* methods; they copy results from one stage to another. |
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* |
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* * Boolean CompletableFuture method x(...) (for example |
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* uniApply) 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 exec to be called twice (SYNC, then |
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* ASYNC); the first to screen and trap exceptions while |
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* arranging to execute, and the second when called from a |
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* task. (A few classes are not used async so take slightly |
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* different forms.) The claim() callback suppresses function |
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* invocation if already claimed by another thread. |
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* |
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* * CompletableFuture method xStage(...) is called from a public |
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* stage method of CompletableFuture x. It screens user |
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* arguments and invokes and/or creates the stage object. If |
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* not async and x is already complete, the action is run |
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* immediately. Otherwise a Completion c is created, pushed to |
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* x's stack (unless done), and started or triggered via |
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* c.tryFire. This also covers races possible if x completes |
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* while pushing. Classes with two inputs (for example BiApply) |
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* deal with races across both while pushing actions. The |
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* second completion is a CoCompletion pointing to the first, |
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* shared so that at most one performs the action. The |
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* multiple-arity methods allOf and anyOf do this pairwise to |
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* 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 exec. Triggering can propagate recursively, so exec |
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* in NESTED mode returns its completed dependent (if one exists) |
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* for further processing by its caller (see method 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 (see especially method Completion.detach). The |
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* screening checks needed anyway harmlessly ignore null arguments |
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* that may have been obtained during races with threads nulling |
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* out fields. We also try to unlink fired Completions from |
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* stacks that might never be popped (see method postFire). |
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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 UNSAFE.compareAndSwapObject(this, RESULT, null, r); |
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} |
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|
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final boolean casStack(Completion cmp, Completion val) { |
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return UNSAFE.compareAndSwapObject(this, STACK, cmp, val); |
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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 UNSAFE.compareAndSwapObject(this, RESULT, null, |
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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 UNSAFE.compareAndSwapObject(this, RESULT, null, |
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(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 UNSAFE.compareAndSwapObject(this, RESULT, null, |
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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 UNSAFE.compareAndSwapObject(this, RESULT, null, |
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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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return (((r instanceof AltResult) && |
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(x = ((AltResult)r).ex) != null && |
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!(x instanceof CompletionException)) ? |
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new AltResult(new CompletionException(x)) : 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 UNSAFE.compareAndSwapObject(this, RESULT, null, |
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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 <T> T 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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@SuppressWarnings("unchecked") T t = (T) r; |
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return t; |
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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 <T> T 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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@SuppressWarnings("unchecked") T t = (T) r; |
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return t; |
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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. |
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* |
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* @since 1.8 |
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*/ |
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public static interface AsynchronousCompletionTask { |
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} |
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|
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private static final boolean useCommonPool = |
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(ForkJoinPool.getCommonPoolParallelism() > 1); |
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|
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/** |
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* Default executor -- ForkJoinPool.commonPool() unless it cannot |
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* support parallelism. |
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*/ |
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private static final Executor asyncPool = useCommonPool ? |
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ForkJoinPool.commonPool() : new ThreadPerTaskExecutor(); |
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|
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/** Fallback if ForkJoinPool.commonPool() cannot support parallelism */ |
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static final class ThreadPerTaskExecutor implements Executor { |
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public void execute(Runnable r) { new Thread(r).start(); } |
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} |
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|
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/** |
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* Null-checks user executor argument, and translates uses of |
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* commonPool to asyncPool in case parallelism disabled. |
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*/ |
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static Executor screenExecutor(Executor e) { |
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if (!useCommonPool && e == ForkJoinPool.commonPool()) |
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return asyncPool; |
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if (e == null) throw new NullPointerException(); |
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return e; |
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} |
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|
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// Modes for Completion.exec. Signedness matters. |
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static final int SYNC = 0; |
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static final int ASYNC = 1; |
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static final int NESTED = -1; |
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|
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/* ------------- Base Completion classes and operations -------------- */ |
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|
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@SuppressWarnings("serial") |
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abstract static class Completion extends ForkJoinTask<Void> |
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implements Runnable, AsynchronousCompletionTask { |
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volatile Completion next; // Treiber stack link |
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|
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/** |
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* Performs completion action if triggered, returning a |
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* dependent that may need propagation, if one exists. |
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* |
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* @param mode SYNC, ASYNC, or NESTED |
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*/ |
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abstract CompletableFuture<?> tryFire(int mode); |
396 |
|
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/** Returns true if possibly still triggerable. Used by cleanStack. */ |
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abstract boolean isLive(); |
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|
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public final void run() { tryFire(ASYNC); } |
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public final boolean exec() { tryFire(ASYNC); return true; } |
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public final Void getRawResult() { return null; } |
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public final void setRawResult(Void v) {} |
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} |
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|
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/** |
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* Pops and tries to trigger all reachable dependents. Call only |
408 |
* when known to be done. |
409 |
*/ |
410 |
final void postComplete() { |
411 |
/* |
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* On each step, variable f holds current dependents to pop |
413 |
* and run. It is extended along only one path at a time, |
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* pushing others to avoid unbounded recursion. |
415 |
*/ |
416 |
CompletableFuture<?> f = this; Completion h; |
417 |
while ((h = f.stack) != null || |
418 |
(f != this && (h = (f = this).stack) != null)) { |
419 |
CompletableFuture<?> d; Completion t; |
420 |
if (f.casStack(h, t = h.next)) { |
421 |
if (t != null) { |
422 |
if (f != this) { // push |
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do {} while (!casStack(h.next = stack, h)); |
424 |
continue; |
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} |
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h.next = null; // detach |
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} |
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f = (d = h.tryFire(NESTED)) == null ? this : d; |
429 |
} |
430 |
} |
431 |
} |
432 |
|
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/** Traverses stack and unlinks dead Completions. */ |
434 |
final void cleanStack() { |
435 |
for (Completion p = null, q = stack; q != null;) { |
436 |
Completion s = q.next; |
437 |
if (q.isLive()) { |
438 |
p = q; |
439 |
q = s; |
440 |
} |
441 |
else if (p == null) { |
442 |
casStack(q, s); |
443 |
q = stack; |
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} |
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else { |
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p.next = s; |
447 |
if (p.isLive()) |
448 |
q = s; |
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else { |
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p = null; // restart |
451 |
q = stack; |
452 |
} |
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} |
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} |
455 |
} |
456 |
|
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/* ------------- One-input Completions -------------- */ |
458 |
|
459 |
/** A Completion with a source, dependent, and executor. */ |
460 |
@SuppressWarnings("serial") |
461 |
abstract static class UniCompletion<T,V> extends Completion { |
462 |
Executor executor; // executor to use (null if none) |
463 |
CompletableFuture<V> dep; // the dependent to complete |
464 |
CompletableFuture<T> src; // source for action |
465 |
|
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UniCompletion(Executor executor, CompletableFuture<V> dep, |
467 |
CompletableFuture<T> src) { |
468 |
this.executor = executor; this.dep = dep; this.src = src; |
469 |
} |
470 |
|
471 |
/** |
472 |
* Returns true if action can be run. Call only when known to |
473 |
* be triggerable. Uses FJ tag bit to ensure that only one |
474 |
* thread claims ownership. If async, starts as task -- a |
475 |
* later call to tryFire will run action. |
476 |
*/ |
477 |
final boolean claim() { |
478 |
Executor e = executor; |
479 |
if (compareAndSetForkJoinTaskTag((short)0, (short)1)) { |
480 |
if (e == null) |
481 |
return true; |
482 |
executor = null; // disable |
483 |
e.execute(this); |
484 |
} |
485 |
return false; |
486 |
} |
487 |
|
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final boolean isLive() { return dep != null; } |
489 |
} |
490 |
|
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/** Pushes the given completion (if it exists) unless done. */ |
492 |
final void push(UniCompletion<?,?> c) { |
493 |
if (c != null) { |
494 |
while (result == null && !casStack(c.next = stack, c)) |
495 |
c.next = null; // clear on failure |
496 |
} |
497 |
} |
498 |
|
499 |
/** |
500 |
* Post-processing by dependent after successful UniCompletion |
501 |
* tryFire. Tries to clean stack of source a, and then either runs |
502 |
* postComplete or returns this to caller, depending on mode. |
503 |
*/ |
504 |
final CompletableFuture<T> postFire(CompletableFuture<?> a, int mode) { |
505 |
if (a != null && a.stack != null) { |
506 |
if (mode < 0 || a.result == null) |
507 |
a.cleanStack(); |
508 |
else |
509 |
a.postComplete(); |
510 |
} |
511 |
if (result != null && stack != null) { |
512 |
if (mode < 0) |
513 |
return this; |
514 |
else |
515 |
postComplete(); |
516 |
} |
517 |
return null; |
518 |
} |
519 |
|
520 |
@SuppressWarnings("serial") |
521 |
static final class UniApply<T,V> extends UniCompletion<T,V> { |
522 |
Function<? super T,? extends V> fn; |
523 |
UniApply(Executor executor, CompletableFuture<V> dep, |
524 |
CompletableFuture<T> src, |
525 |
Function<? super T,? extends V> fn) { |
526 |
super(executor, dep, src); this.fn = fn; |
527 |
} |
528 |
final CompletableFuture<V> tryFire(int mode) { |
529 |
CompletableFuture<V> d; CompletableFuture<T> a; |
530 |
if ((d = dep) == null || |
531 |
!d.uniApply(a = src, fn, mode > 0 ? null : this)) |
532 |
return null; |
533 |
dep = null; src = null; fn = null; |
534 |
return d.postFire(a, mode); |
535 |
} |
536 |
} |
537 |
|
538 |
final <S> boolean uniApply(CompletableFuture<S> a, |
539 |
Function<? super S,? extends T> f, |
540 |
UniApply<S,T> c) { |
541 |
Object r; Throwable x; |
542 |
if (a == null || (r = a.result) == null || f == null) |
543 |
return false; |
544 |
tryComplete: if (result == null) { |
545 |
if (r instanceof AltResult) { |
546 |
if ((x = ((AltResult)r).ex) != null) { |
547 |
completeThrowable(x, r); |
548 |
break tryComplete; |
549 |
} |
550 |
r = null; |
551 |
} |
552 |
try { |
553 |
if (c != null && !c.claim()) |
554 |
return false; |
555 |
@SuppressWarnings("unchecked") S s = (S) r; |
556 |
completeValue(f.apply(s)); |
557 |
} catch (Throwable ex) { |
558 |
completeThrowable(ex); |
559 |
} |
560 |
} |
561 |
return true; |
562 |
} |
563 |
|
564 |
private <V> CompletableFuture<V> uniApplyStage( |
565 |
Executor e, Function<? super T,? extends V> f) { |
566 |
if (f == null) throw new NullPointerException(); |
567 |
CompletableFuture<V> d = new CompletableFuture<V>(); |
568 |
if (e != null || !d.uniApply(this, f, null)) { |
569 |
UniApply<T,V> c = new UniApply<T,V>(e, d, this, f); |
570 |
push(c); |
571 |
c.tryFire(SYNC); |
572 |
} |
573 |
return d; |
574 |
} |
575 |
|
576 |
@SuppressWarnings("serial") |
577 |
static final class UniAccept<T> extends UniCompletion<T,Void> { |
578 |
Consumer<? super T> fn; |
579 |
UniAccept(Executor executor, CompletableFuture<Void> dep, |
580 |
CompletableFuture<T> src, Consumer<? super T> fn) { |
581 |
super(executor, dep, src); this.fn = fn; |
582 |
} |
583 |
final CompletableFuture<Void> tryFire(int mode) { |
584 |
CompletableFuture<Void> d; CompletableFuture<T> a; |
585 |
if ((d = dep) == null || |
586 |
!d.uniAccept(a = src, fn, mode > 0 ? null : this)) |
587 |
return null; |
588 |
dep = null; src = null; fn = null; |
589 |
return d.postFire(a, mode); |
590 |
} |
591 |
} |
592 |
|
593 |
final <S> boolean uniAccept(CompletableFuture<S> a, |
594 |
Consumer<? super S> f, UniAccept<S> c) { |
595 |
Object r; Throwable x; |
596 |
if (a == null || (r = a.result) == null || f == null) |
597 |
return false; |
598 |
tryComplete: if (result == null) { |
599 |
if (r instanceof AltResult) { |
600 |
if ((x = ((AltResult)r).ex) != null) { |
601 |
completeThrowable(x, r); |
602 |
break tryComplete; |
603 |
} |
604 |
r = null; |
605 |
} |
606 |
try { |
607 |
if (c != null && !c.claim()) |
608 |
return false; |
609 |
@SuppressWarnings("unchecked") S s = (S) r; |
610 |
f.accept(s); |
611 |
completeNull(); |
612 |
} catch (Throwable ex) { |
613 |
completeThrowable(ex); |
614 |
} |
615 |
} |
616 |
return true; |
617 |
} |
618 |
|
619 |
private CompletableFuture<Void> uniAcceptStage(Executor e, |
620 |
Consumer<? super T> f) { |
621 |
if (f == null) throw new NullPointerException(); |
622 |
CompletableFuture<Void> d = new CompletableFuture<Void>(); |
623 |
if (e != null || !d.uniAccept(this, f, null)) { |
624 |
UniAccept<T> c = new UniAccept<T>(e, d, this, f); |
625 |
push(c); |
626 |
c.tryFire(SYNC); |
627 |
} |
628 |
return d; |
629 |
} |
630 |
|
631 |
@SuppressWarnings("serial") |
632 |
static final class UniRun<T> extends UniCompletion<T,Void> { |
633 |
Runnable fn; |
634 |
UniRun(Executor executor, CompletableFuture<Void> dep, |
635 |
CompletableFuture<T> src, Runnable fn) { |
636 |
super(executor, dep, src); this.fn = fn; |
637 |
} |
638 |
final CompletableFuture<Void> tryFire(int mode) { |
639 |
CompletableFuture<Void> d; CompletableFuture<T> a; |
640 |
if ((d = dep) == null || |
641 |
!d.uniRun(a = src, fn, mode > 0 ? null : this)) |
642 |
return null; |
643 |
dep = null; src = null; fn = null; |
644 |
return d.postFire(a, mode); |
645 |
} |
646 |
} |
647 |
|
648 |
final boolean uniRun(CompletableFuture<?> a, Runnable f, UniRun<?> c) { |
649 |
Object r; Throwable x; |
650 |
if (a == null || (r = a.result) == null || f == null) |
651 |
return false; |
652 |
if (result == null) { |
653 |
if (r instanceof AltResult && (x = ((AltResult)r).ex) != null) |
654 |
completeThrowable(x, r); |
655 |
else |
656 |
try { |
657 |
if (c != null && !c.claim()) |
658 |
return false; |
659 |
f.run(); |
660 |
completeNull(); |
661 |
} catch (Throwable ex) { |
662 |
completeThrowable(ex); |
663 |
} |
664 |
} |
665 |
return true; |
666 |
} |
667 |
|
668 |
private CompletableFuture<Void> uniRunStage(Executor e, Runnable f) { |
669 |
if (f == null) throw new NullPointerException(); |
670 |
CompletableFuture<Void> d = new CompletableFuture<Void>(); |
671 |
if (e != null || !d.uniRun(this, f, null)) { |
672 |
UniRun<T> c = new UniRun<T>(e, d, this, f); |
673 |
push(c); |
674 |
c.tryFire(SYNC); |
675 |
} |
676 |
return d; |
677 |
} |
678 |
|
679 |
@SuppressWarnings("serial") |
680 |
static final class UniWhenComplete<T> extends UniCompletion<T,T> { |
681 |
BiConsumer<? super T, ? super Throwable> fn; |
682 |
UniWhenComplete(Executor executor, CompletableFuture<T> dep, |
683 |
CompletableFuture<T> src, |
684 |
BiConsumer<? super T, ? super Throwable> fn) { |
685 |
super(executor, dep, src); this.fn = fn; |
686 |
} |
687 |
final CompletableFuture<T> tryFire(int mode) { |
688 |
CompletableFuture<T> d; CompletableFuture<T> a; |
689 |
if ((d = dep) == null || |
690 |
!d.uniWhenComplete(a = src, fn, mode > 0 ? null : this)) |
691 |
return null; |
692 |
dep = null; src = null; fn = null; |
693 |
return d.postFire(a, mode); |
694 |
} |
695 |
} |
696 |
|
697 |
final boolean uniWhenComplete(CompletableFuture<T> a, |
698 |
BiConsumer<? super T,? super Throwable> f, |
699 |
UniWhenComplete<T> c) { |
700 |
Object r; T t; Throwable x = null; |
701 |
if (a == null || (r = a.result) == null || f == null) |
702 |
return false; |
703 |
if (result == null) { |
704 |
try { |
705 |
if (c != null && !c.claim()) |
706 |
return false; |
707 |
if (r instanceof AltResult) { |
708 |
x = ((AltResult)r).ex; |
709 |
t = null; |
710 |
} else { |
711 |
@SuppressWarnings("unchecked") T tr = (T) r; |
712 |
t = tr; |
713 |
} |
714 |
f.accept(t, x); |
715 |
if (x == null) { |
716 |
internalComplete(r); |
717 |
return true; |
718 |
} |
719 |
} catch (Throwable ex) { |
720 |
if (x == null) |
721 |
x = ex; |
722 |
} |
723 |
completeThrowable(x, r); |
724 |
} |
725 |
return true; |
726 |
} |
727 |
|
728 |
private CompletableFuture<T> uniWhenCompleteStage( |
729 |
Executor e, BiConsumer<? super T, ? super Throwable> f) { |
730 |
if (f == null) throw new NullPointerException(); |
731 |
CompletableFuture<T> d = new CompletableFuture<T>(); |
732 |
if (e != null || !d.uniWhenComplete(this, f, null)) { |
733 |
UniWhenComplete<T> c = new UniWhenComplete<T>(e, d, this, f); |
734 |
push(c); |
735 |
c.tryFire(SYNC); |
736 |
} |
737 |
return d; |
738 |
} |
739 |
|
740 |
@SuppressWarnings("serial") |
741 |
static final class UniHandle<T,V> extends UniCompletion<T,V> { |
742 |
BiFunction<? super T, Throwable, ? extends V> fn; |
743 |
UniHandle(Executor executor, CompletableFuture<V> dep, |
744 |
CompletableFuture<T> src, |
745 |
BiFunction<? super T, Throwable, ? extends V> fn) { |
746 |
super(executor, dep, src); this.fn = fn; |
747 |
} |
748 |
final CompletableFuture<V> tryFire(int mode) { |
749 |
CompletableFuture<V> d; CompletableFuture<T> a; |
750 |
if ((d = dep) == null || |
751 |
!d.uniHandle(a = src, fn, mode > 0 ? null : this)) |
752 |
return null; |
753 |
dep = null; src = null; fn = null; |
754 |
return d.postFire(a, mode); |
755 |
} |
756 |
} |
757 |
|
758 |
final <S> boolean uniHandle(CompletableFuture<S> a, |
759 |
BiFunction<? super S, Throwable, ? extends T> f, |
760 |
UniHandle<S,T> c) { |
761 |
Object r; S s; Throwable x; |
762 |
if (a == null || (r = a.result) == null || f == null) |
763 |
return false; |
764 |
if (result == null) { |
765 |
try { |
766 |
if (c != null && !c.claim()) |
767 |
return false; |
768 |
if (r instanceof AltResult) { |
769 |
x = ((AltResult)r).ex; |
770 |
s = null; |
771 |
} else { |
772 |
x = null; |
773 |
@SuppressWarnings("unchecked") S ss = (S) r; |
774 |
s = ss; |
775 |
} |
776 |
completeValue(f.apply(s, x)); |
777 |
} catch (Throwable ex) { |
778 |
completeThrowable(ex); |
779 |
} |
780 |
} |
781 |
return true; |
782 |
} |
783 |
|
784 |
private <V> CompletableFuture<V> uniHandleStage( |
785 |
Executor e, BiFunction<? super T, Throwable, ? extends V> f) { |
786 |
if (f == null) throw new NullPointerException(); |
787 |
CompletableFuture<V> d = new CompletableFuture<V>(); |
788 |
if (e != null || !d.uniHandle(this, f, null)) { |
789 |
UniHandle<T,V> c = new UniHandle<T,V>(e, d, this, f); |
790 |
push(c); |
791 |
c.tryFire(SYNC); |
792 |
} |
793 |
return d; |
794 |
} |
795 |
|
796 |
@SuppressWarnings("serial") |
797 |
static final class UniExceptionally<T> extends UniCompletion<T,T> { |
798 |
Function<? super Throwable, ? extends T> fn; |
799 |
UniExceptionally(CompletableFuture<T> dep, CompletableFuture<T> src, |
800 |
Function<? super Throwable, ? extends T> fn) { |
801 |
super(null, dep, src); this.fn = fn; |
802 |
} |
803 |
final CompletableFuture<T> tryFire(int mode) { // never ASYNC |
804 |
// assert mode != ASYNC; |
805 |
CompletableFuture<T> d; CompletableFuture<T> a; |
806 |
if ((d = dep) == null || !d.uniExceptionally(a = src, fn, this)) |
807 |
return null; |
808 |
dep = null; src = null; fn = null; |
809 |
return d.postFire(a, mode); |
810 |
} |
811 |
} |
812 |
|
813 |
final boolean uniExceptionally(CompletableFuture<T> a, |
814 |
Function<? super Throwable, ? extends T> f, |
815 |
UniExceptionally<T> c) { |
816 |
Object r; Throwable x; |
817 |
if (a == null || (r = a.result) == null || f == null) |
818 |
return false; |
819 |
if (result == null) { |
820 |
try { |
821 |
if (r instanceof AltResult && (x = ((AltResult)r).ex) != null) { |
822 |
if (c != null && !c.claim()) |
823 |
return false; |
824 |
completeValue(f.apply(x)); |
825 |
} else |
826 |
internalComplete(r); |
827 |
} catch (Throwable ex) { |
828 |
completeThrowable(ex); |
829 |
} |
830 |
} |
831 |
return true; |
832 |
} |
833 |
|
834 |
private CompletableFuture<T> uniExceptionallyStage( |
835 |
Function<Throwable, ? extends T> f) { |
836 |
if (f == null) throw new NullPointerException(); |
837 |
CompletableFuture<T> d = new CompletableFuture<T>(); |
838 |
if (!d.uniExceptionally(this, f, null)) { |
839 |
UniExceptionally<T> c = new UniExceptionally<T>(d, this, f); |
840 |
push(c); |
841 |
c.tryFire(SYNC); |
842 |
} |
843 |
return d; |
844 |
} |
845 |
|
846 |
@SuppressWarnings("serial") |
847 |
static final class UniRelay<T> extends UniCompletion<T,T> { // for Compose |
848 |
UniRelay(CompletableFuture<T> dep, CompletableFuture<T> src) { |
849 |
super(null, dep, src); |
850 |
} |
851 |
final CompletableFuture<T> tryFire(int mode) { |
852 |
CompletableFuture<T> d; CompletableFuture<T> a; |
853 |
if ((d = dep) == null || !d.uniRelay(a = src)) |
854 |
return null; |
855 |
src = null; dep = null; |
856 |
return d.postFire(a, mode); |
857 |
} |
858 |
} |
859 |
|
860 |
final boolean uniRelay(CompletableFuture<T> a) { |
861 |
Object r; |
862 |
if (a == null || (r = a.result) == null) |
863 |
return false; |
864 |
if (result == null) // no need to claim |
865 |
completeRelay(r); |
866 |
return true; |
867 |
} |
868 |
|
869 |
@SuppressWarnings("serial") |
870 |
static final class UniCompose<T,V> extends UniCompletion<T,V> { |
871 |
Function<? super T, ? extends CompletionStage<V>> fn; |
872 |
UniCompose(Executor executor, CompletableFuture<V> dep, |
873 |
CompletableFuture<T> src, |
874 |
Function<? super T, ? extends CompletionStage<V>> fn) { |
875 |
super(executor, dep, src); this.fn = fn; |
876 |
} |
877 |
final CompletableFuture<V> tryFire(int mode) { |
878 |
CompletableFuture<V> d; CompletableFuture<T> a; |
879 |
if ((d = dep) == null || |
880 |
!d.uniCompose(a = src, fn, mode > 0 ? null : this)) |
881 |
return null; |
882 |
dep = null; src = null; fn = null; |
883 |
return d.postFire(a, mode); |
884 |
} |
885 |
} |
886 |
|
887 |
final <S> boolean uniCompose( |
888 |
CompletableFuture<S> a, |
889 |
Function<? super S, ? extends CompletionStage<T>> f, |
890 |
UniCompose<S,T> c) { |
891 |
Object r; Throwable x; |
892 |
if (a == null || (r = a.result) == null || f == null) |
893 |
return false; |
894 |
tryComplete: if (result == null) { |
895 |
if (r instanceof AltResult) { |
896 |
if ((x = ((AltResult)r).ex) != null) { |
897 |
completeThrowable(x, r); |
898 |
break tryComplete; |
899 |
} |
900 |
r = null; |
901 |
} |
902 |
try { |
903 |
if (c != null && !c.claim()) |
904 |
return false; |
905 |
@SuppressWarnings("unchecked") S s = (S) r; |
906 |
CompletableFuture<T> g = f.apply(s).toCompletableFuture(); |
907 |
if (g.result == null || !uniRelay(g)) { |
908 |
UniRelay<T> copy = new UniRelay<T>(this, g); |
909 |
g.push(copy); |
910 |
copy.tryFire(SYNC); |
911 |
if (result == null) |
912 |
return false; |
913 |
} |
914 |
} catch (Throwable ex) { |
915 |
completeThrowable(ex); |
916 |
} |
917 |
} |
918 |
return true; |
919 |
} |
920 |
|
921 |
private <V> CompletableFuture<V> uniComposeStage( |
922 |
Executor e, Function<? super T, ? extends CompletionStage<V>> f) { |
923 |
if (f == null) throw new NullPointerException(); |
924 |
Object r; Throwable x; |
925 |
if (e == null && (r = result) != null) { |
926 |
// try to return function result directly |
927 |
if (r instanceof AltResult) { |
928 |
if ((x = ((AltResult)r).ex) != null) { |
929 |
return new CompletableFuture<V>(encodeThrowable(x, r)); |
930 |
} |
931 |
r = null; |
932 |
} |
933 |
try { |
934 |
@SuppressWarnings("unchecked") T t = (T) r; |
935 |
return f.apply(t).toCompletableFuture(); |
936 |
} catch (Throwable ex) { |
937 |
return new CompletableFuture<V>(encodeThrowable(ex)); |
938 |
} |
939 |
} |
940 |
CompletableFuture<V> d = new CompletableFuture<V>(); |
941 |
UniCompose<T,V> c = new UniCompose<T,V>(e, d, this, f); |
942 |
push(c); |
943 |
c.tryFire(SYNC); |
944 |
return d; |
945 |
} |
946 |
|
947 |
/* ------------- Two-input Completions -------------- */ |
948 |
|
949 |
/** A Completion for an action with two sources */ |
950 |
@SuppressWarnings("serial") |
951 |
abstract static class BiCompletion<T,U,V> extends UniCompletion<T,V> { |
952 |
CompletableFuture<U> snd; // second source for action |
953 |
BiCompletion(Executor executor, CompletableFuture<V> dep, |
954 |
CompletableFuture<T> src, CompletableFuture<U> snd) { |
955 |
super(executor, dep, src); this.snd = snd; |
956 |
} |
957 |
} |
958 |
|
959 |
/** A Completion delegating to a BiCompletion */ |
960 |
@SuppressWarnings("serial") |
961 |
static final class CoCompletion extends Completion { |
962 |
BiCompletion<?,?,?> base; |
963 |
CoCompletion(BiCompletion<?,?,?> base) { this.base = base; } |
964 |
final CompletableFuture<?> tryFire(int mode) { |
965 |
BiCompletion<?,?,?> c; CompletableFuture<?> d; |
966 |
if ((c = base) == null || (d = c.tryFire(mode)) == null) |
967 |
return null; |
968 |
base = null; // detach |
969 |
return d; |
970 |
} |
971 |
final boolean isLive() { |
972 |
BiCompletion<?,?,?> c; |
973 |
return (c = base) != null && c.dep != null; |
974 |
} |
975 |
} |
976 |
|
977 |
/** Pushes completion to this and b unless both done. */ |
978 |
final void bipush(CompletableFuture<?> b, BiCompletion<?,?,?> c) { |
979 |
if (c != null) { |
980 |
Object r; |
981 |
while ((r = result) == null && !casStack(c.next = stack, c)) |
982 |
c.next = null; |
983 |
if (b != null && b != this && b.result == null) { |
984 |
Completion q = (r != null) ? c : new CoCompletion(c); |
985 |
while (b.result == null && !b.casStack(q.next = b.stack, q)) |
986 |
q.next = null; |
987 |
} |
988 |
} |
989 |
} |
990 |
|
991 |
/** Post-processing after successful BiCompletion tryFire. */ |
992 |
final CompletableFuture<T> postFire(CompletableFuture<?> a, |
993 |
CompletableFuture<?> b, int mode) { |
994 |
if (b != null && b.stack != null) { // clean second source |
995 |
if (mode < 0 || b.result == null) |
996 |
b.cleanStack(); |
997 |
else |
998 |
b.postComplete(); |
999 |
} |
1000 |
return postFire(a, mode); |
1001 |
} |
1002 |
|
1003 |
@SuppressWarnings("serial") |
1004 |
static final class BiApply<T,U,V> extends BiCompletion<T,U,V> { |
1005 |
BiFunction<? super T,? super U,? extends V> fn; |
1006 |
BiApply(Executor executor, CompletableFuture<V> dep, |
1007 |
CompletableFuture<T> src, CompletableFuture<U> snd, |
1008 |
BiFunction<? super T,? super U,? extends V> fn) { |
1009 |
super(executor, dep, src, snd); this.fn = fn; |
1010 |
} |
1011 |
final CompletableFuture<V> tryFire(int mode) { |
1012 |
CompletableFuture<V> d; |
1013 |
CompletableFuture<T> a; |
1014 |
CompletableFuture<U> b; |
1015 |
if ((d = dep) == null || |
1016 |
!d.biApply(a = src, b = snd, fn, mode > 0 ? null : this)) |
1017 |
return null; |
1018 |
dep = null; src = null; snd = null; fn = null; |
1019 |
return d.postFire(a, b, mode); |
1020 |
} |
1021 |
} |
1022 |
|
1023 |
final <R,S> boolean biApply(CompletableFuture<R> a, |
1024 |
CompletableFuture<S> b, |
1025 |
BiFunction<? super R,? super S,? extends T> f, |
1026 |
BiApply<R,S,T> c) { |
1027 |
Object r, s; Throwable x; |
1028 |
if (a == null || (r = a.result) == null || |
1029 |
b == null || (s = b.result) == null || f == null) |
1030 |
return false; |
1031 |
tryComplete: if (result == null) { |
1032 |
if (r instanceof AltResult) { |
1033 |
if ((x = ((AltResult)r).ex) != null) { |
1034 |
completeThrowable(x, r); |
1035 |
break tryComplete; |
1036 |
} |
1037 |
r = null; |
1038 |
} |
1039 |
if (s instanceof AltResult) { |
1040 |
if ((x = ((AltResult)s).ex) != null) { |
1041 |
completeThrowable(x, s); |
1042 |
break tryComplete; |
1043 |
} |
1044 |
s = null; |
1045 |
} |
1046 |
try { |
1047 |
if (c != null && !c.claim()) |
1048 |
return false; |
1049 |
@SuppressWarnings("unchecked") R rr = (R) r; |
1050 |
@SuppressWarnings("unchecked") S ss = (S) s; |
1051 |
completeValue(f.apply(rr, ss)); |
1052 |
} catch (Throwable ex) { |
1053 |
completeThrowable(ex); |
1054 |
} |
1055 |
} |
1056 |
return true; |
1057 |
} |
1058 |
|
1059 |
private <U,V> CompletableFuture<V> biApplyStage( |
1060 |
Executor e, CompletionStage<U> o, |
1061 |
BiFunction<? super T,? super U,? extends V> f) { |
1062 |
CompletableFuture<U> b; |
1063 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1064 |
throw new NullPointerException(); |
1065 |
CompletableFuture<V> d = new CompletableFuture<V>(); |
1066 |
if (e != null || !d.biApply(this, b, f, null)) { |
1067 |
BiApply<T,U,V> c = new BiApply<T,U,V>(e, d, this, b, f); |
1068 |
bipush(b, c); |
1069 |
c.tryFire(SYNC); |
1070 |
} |
1071 |
return d; |
1072 |
} |
1073 |
|
1074 |
@SuppressWarnings("serial") |
1075 |
static final class BiAccept<T,U> extends BiCompletion<T,U,Void> { |
1076 |
BiConsumer<? super T,? super U> fn; |
1077 |
BiAccept(Executor executor, CompletableFuture<Void> dep, |
1078 |
CompletableFuture<T> src, CompletableFuture<U> snd, |
1079 |
BiConsumer<? super T,? super U> fn) { |
1080 |
super(executor, dep, src, snd); this.fn = fn; |
1081 |
} |
1082 |
final CompletableFuture<Void> tryFire(int mode) { |
1083 |
CompletableFuture<Void> d; |
1084 |
CompletableFuture<T> a; |
1085 |
CompletableFuture<U> b; |
1086 |
if ((d = dep) == null || |
1087 |
!d.biAccept(a = src, b = snd, fn, mode > 0 ? null : this)) |
1088 |
return null; |
1089 |
dep = null; src = null; snd = null; fn = null; |
1090 |
return d.postFire(a, b, mode); |
1091 |
} |
1092 |
} |
1093 |
|
1094 |
final <R,S> boolean biAccept(CompletableFuture<R> a, |
1095 |
CompletableFuture<S> b, |
1096 |
BiConsumer<? super R,? super S> f, |
1097 |
BiAccept<R,S> c) { |
1098 |
Object r, s; Throwable x; |
1099 |
if (a == null || (r = a.result) == null || |
1100 |
b == null || (s = b.result) == null || f == null) |
1101 |
return false; |
1102 |
tryComplete: if (result == null) { |
1103 |
if (r instanceof AltResult) { |
1104 |
if ((x = ((AltResult)r).ex) != null) { |
1105 |
completeThrowable(x, r); |
1106 |
break tryComplete; |
1107 |
} |
1108 |
r = null; |
1109 |
} |
1110 |
if (s instanceof AltResult) { |
1111 |
if ((x = ((AltResult)s).ex) != null) { |
1112 |
completeThrowable(x, s); |
1113 |
break tryComplete; |
1114 |
} |
1115 |
s = null; |
1116 |
} |
1117 |
try { |
1118 |
if (c != null && !c.claim()) |
1119 |
return false; |
1120 |
@SuppressWarnings("unchecked") R rr = (R) r; |
1121 |
@SuppressWarnings("unchecked") S ss = (S) s; |
1122 |
f.accept(rr, ss); |
1123 |
completeNull(); |
1124 |
} catch (Throwable ex) { |
1125 |
completeThrowable(ex); |
1126 |
} |
1127 |
} |
1128 |
return true; |
1129 |
} |
1130 |
|
1131 |
private <U> CompletableFuture<Void> biAcceptStage( |
1132 |
Executor e, CompletionStage<U> o, |
1133 |
BiConsumer<? super T,? super U> f) { |
1134 |
CompletableFuture<U> b; |
1135 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1136 |
throw new NullPointerException(); |
1137 |
CompletableFuture<Void> d = new CompletableFuture<Void>(); |
1138 |
if (e != null || !d.biAccept(this, b, f, null)) { |
1139 |
BiAccept<T,U> c = new BiAccept<T,U>(e, d, this, b, f); |
1140 |
bipush(b, c); |
1141 |
c.tryFire(SYNC); |
1142 |
} |
1143 |
return d; |
1144 |
} |
1145 |
|
1146 |
@SuppressWarnings("serial") |
1147 |
static final class BiRun<T,U> extends BiCompletion<T,U,Void> { |
1148 |
Runnable fn; |
1149 |
BiRun(Executor executor, CompletableFuture<Void> dep, |
1150 |
CompletableFuture<T> src, |
1151 |
CompletableFuture<U> snd, |
1152 |
Runnable fn) { |
1153 |
super(executor, dep, src, snd); this.fn = fn; |
1154 |
} |
1155 |
final CompletableFuture<Void> tryFire(int mode) { |
1156 |
CompletableFuture<Void> d; |
1157 |
CompletableFuture<T> a; |
1158 |
CompletableFuture<U> b; |
1159 |
if ((d = dep) == null || |
1160 |
!d.biRun(a = src, b = snd, fn, mode > 0 ? null : this)) |
1161 |
return null; |
1162 |
dep = null; src = null; snd = null; fn = null; |
1163 |
return d.postFire(a, b, mode); |
1164 |
} |
1165 |
} |
1166 |
|
1167 |
final boolean biRun(CompletableFuture<?> a, CompletableFuture<?> b, |
1168 |
Runnable f, BiRun<?,?> c) { |
1169 |
Object r, s; Throwable x; |
1170 |
if (a == null || (r = a.result) == null || |
1171 |
b == null || (s = b.result) == null || f == null) |
1172 |
return false; |
1173 |
if (result == null) { |
1174 |
if (r instanceof AltResult && (x = ((AltResult)r).ex) != null) |
1175 |
completeThrowable(x, r); |
1176 |
else if (s instanceof AltResult && (x = ((AltResult)s).ex) != null) |
1177 |
completeThrowable(x, s); |
1178 |
else |
1179 |
try { |
1180 |
if (c != null && !c.claim()) |
1181 |
return false; |
1182 |
f.run(); |
1183 |
completeNull(); |
1184 |
} catch (Throwable ex) { |
1185 |
completeThrowable(ex); |
1186 |
} |
1187 |
} |
1188 |
return true; |
1189 |
} |
1190 |
|
1191 |
private CompletableFuture<Void> biRunStage(Executor e, CompletionStage<?> o, |
1192 |
Runnable f) { |
1193 |
CompletableFuture<?> b; |
1194 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1195 |
throw new NullPointerException(); |
1196 |
CompletableFuture<Void> d = new CompletableFuture<Void>(); |
1197 |
if (e != null || !d.biRun(this, b, f, null)) { |
1198 |
BiRun<T,?> c = new BiRun<>(e, d, this, b, f); |
1199 |
bipush(b, c); |
1200 |
c.tryFire(SYNC); |
1201 |
} |
1202 |
return d; |
1203 |
} |
1204 |
|
1205 |
@SuppressWarnings("serial") |
1206 |
static final class BiRelay<T,U> extends BiCompletion<T,U,Void> { // for And |
1207 |
BiRelay(CompletableFuture<Void> dep, |
1208 |
CompletableFuture<T> src, |
1209 |
CompletableFuture<U> snd) { |
1210 |
super(null, dep, src, snd); |
1211 |
} |
1212 |
final CompletableFuture<Void> tryFire(int mode) { |
1213 |
CompletableFuture<Void> d; |
1214 |
CompletableFuture<T> a; |
1215 |
CompletableFuture<U> b; |
1216 |
if ((d = dep) == null || !d.biRelay(a = src, b = snd)) |
1217 |
return null; |
1218 |
src = null; snd = null; dep = null; |
1219 |
return d.postFire(a, b, mode); |
1220 |
} |
1221 |
} |
1222 |
|
1223 |
boolean biRelay(CompletableFuture<?> a, CompletableFuture<?> b) { |
1224 |
Object r, s; Throwable x; |
1225 |
if (a == null || (r = a.result) == null || |
1226 |
b == null || (s = b.result) == null) |
1227 |
return false; |
1228 |
if (result == null) { |
1229 |
if (r instanceof AltResult && (x = ((AltResult)r).ex) != null) |
1230 |
completeThrowable(x, r); |
1231 |
else if (s instanceof AltResult && (x = ((AltResult)s).ex) != null) |
1232 |
completeThrowable(x, s); |
1233 |
else |
1234 |
completeNull(); |
1235 |
} |
1236 |
return true; |
1237 |
} |
1238 |
|
1239 |
/** Recursively constructs a tree of completions. */ |
1240 |
static CompletableFuture<Void> andTree(CompletableFuture<?>[] cfs, |
1241 |
int lo, int hi) { |
1242 |
CompletableFuture<Void> d = new CompletableFuture<Void>(); |
1243 |
if (lo > hi) // empty |
1244 |
d.result = NIL; |
1245 |
else { |
1246 |
CompletableFuture<?> a, b; |
1247 |
int mid = (lo + hi) >>> 1; |
1248 |
if ((a = (lo == mid ? cfs[lo] : |
1249 |
andTree(cfs, lo, mid))) == null || |
1250 |
(b = (lo == hi ? a : (hi == mid+1) ? cfs[hi] : |
1251 |
andTree(cfs, mid+1, hi))) == null) |
1252 |
throw new NullPointerException(); |
1253 |
if (!d.biRelay(a, b)) { |
1254 |
BiRelay<?,?> c = new BiRelay<>(d, a, b); |
1255 |
a.bipush(b, c); |
1256 |
c.tryFire(SYNC); |
1257 |
} |
1258 |
} |
1259 |
return d; |
1260 |
} |
1261 |
|
1262 |
/* ------------- Projected (Ored) BiCompletions -------------- */ |
1263 |
|
1264 |
/** Pushes completion to this and b unless either done. */ |
1265 |
final void orpush(CompletableFuture<?> b, BiCompletion<?,?,?> c) { |
1266 |
if (c != null) { |
1267 |
while ((b == null || b.result == null) && result == null) { |
1268 |
if (casStack(c.next = stack, c)) { |
1269 |
if (b != null && b != this && b.result == null) { |
1270 |
Completion q = new CoCompletion(c); |
1271 |
while (result == null && b.result == null && |
1272 |
!b.casStack(q.next = b.stack, q)) |
1273 |
q.next = null; |
1274 |
} |
1275 |
break; |
1276 |
} |
1277 |
c.next = null; |
1278 |
} |
1279 |
} |
1280 |
} |
1281 |
|
1282 |
@SuppressWarnings("serial") |
1283 |
static final class OrApply<T,U extends T,V> extends BiCompletion<T,U,V> { |
1284 |
Function<? super T,? extends V> fn; |
1285 |
OrApply(Executor executor, CompletableFuture<V> dep, |
1286 |
CompletableFuture<T> src, |
1287 |
CompletableFuture<U> snd, |
1288 |
Function<? super T,? extends V> fn) { |
1289 |
super(executor, dep, src, snd); this.fn = fn; |
1290 |
} |
1291 |
final CompletableFuture<V> tryFire(int mode) { |
1292 |
CompletableFuture<V> d; |
1293 |
CompletableFuture<T> a; |
1294 |
CompletableFuture<U> b; |
1295 |
if ((d = dep) == null || |
1296 |
!d.orApply(a = src, b = snd, fn, mode > 0 ? null : this)) |
1297 |
return null; |
1298 |
dep = null; src = null; snd = null; fn = null; |
1299 |
return d.postFire(a, b, mode); |
1300 |
} |
1301 |
} |
1302 |
|
1303 |
final <R,S extends R> boolean orApply(CompletableFuture<R> a, |
1304 |
CompletableFuture<S> b, |
1305 |
Function<? super R, ? extends T> f, |
1306 |
OrApply<R,S,T> c) { |
1307 |
Object r; Throwable x; |
1308 |
if (a == null || b == null || |
1309 |
((r = a.result) == null && (r = b.result) == null) || f == null) |
1310 |
return false; |
1311 |
tryComplete: if (result == null) { |
1312 |
try { |
1313 |
if (c != null && !c.claim()) |
1314 |
return false; |
1315 |
if (r instanceof AltResult) { |
1316 |
if ((x = ((AltResult)r).ex) != null) { |
1317 |
completeThrowable(x, r); |
1318 |
break tryComplete; |
1319 |
} |
1320 |
r = null; |
1321 |
} |
1322 |
@SuppressWarnings("unchecked") R rr = (R) r; |
1323 |
completeValue(f.apply(rr)); |
1324 |
} catch (Throwable ex) { |
1325 |
completeThrowable(ex); |
1326 |
} |
1327 |
} |
1328 |
return true; |
1329 |
} |
1330 |
|
1331 |
private <U extends T,V> CompletableFuture<V> orApplyStage( |
1332 |
Executor e, CompletionStage<U> o, |
1333 |
Function<? super T, ? extends V> f) { |
1334 |
CompletableFuture<U> b; |
1335 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1336 |
throw new NullPointerException(); |
1337 |
CompletableFuture<V> d = new CompletableFuture<V>(); |
1338 |
if (e != null || !d.orApply(this, b, f, null)) { |
1339 |
OrApply<T,U,V> c = new OrApply<T,U,V>(e, d, this, b, f); |
1340 |
orpush(b, c); |
1341 |
c.tryFire(SYNC); |
1342 |
} |
1343 |
return d; |
1344 |
} |
1345 |
|
1346 |
@SuppressWarnings("serial") |
1347 |
static final class OrAccept<T,U extends T> extends BiCompletion<T,U,Void> { |
1348 |
Consumer<? super T> fn; |
1349 |
OrAccept(Executor executor, CompletableFuture<Void> dep, |
1350 |
CompletableFuture<T> src, |
1351 |
CompletableFuture<U> snd, |
1352 |
Consumer<? super T> fn) { |
1353 |
super(executor, dep, src, snd); this.fn = fn; |
1354 |
} |
1355 |
final CompletableFuture<Void> tryFire(int mode) { |
1356 |
CompletableFuture<Void> d; |
1357 |
CompletableFuture<T> a; |
1358 |
CompletableFuture<U> b; |
1359 |
if ((d = dep) == null || |
1360 |
!d.orAccept(a = src, b = snd, fn, mode > 0 ? null : this)) |
1361 |
return null; |
1362 |
dep = null; src = null; snd = null; fn = null; |
1363 |
return d.postFire(a, b, mode); |
1364 |
} |
1365 |
} |
1366 |
|
1367 |
final <R,S extends R> boolean orAccept(CompletableFuture<R> a, |
1368 |
CompletableFuture<S> b, |
1369 |
Consumer<? super R> f, |
1370 |
OrAccept<R,S> c) { |
1371 |
Object r; Throwable x; |
1372 |
if (a == null || b == null || |
1373 |
((r = a.result) == null && (r = b.result) == null) || f == null) |
1374 |
return false; |
1375 |
tryComplete: if (result == null) { |
1376 |
try { |
1377 |
if (c != null && !c.claim()) |
1378 |
return false; |
1379 |
if (r instanceof AltResult) { |
1380 |
if ((x = ((AltResult)r).ex) != null) { |
1381 |
completeThrowable(x, r); |
1382 |
break tryComplete; |
1383 |
} |
1384 |
r = null; |
1385 |
} |
1386 |
@SuppressWarnings("unchecked") R rr = (R) r; |
1387 |
f.accept(rr); |
1388 |
completeNull(); |
1389 |
} catch (Throwable ex) { |
1390 |
completeThrowable(ex); |
1391 |
} |
1392 |
} |
1393 |
return true; |
1394 |
} |
1395 |
|
1396 |
private <U extends T> CompletableFuture<Void> orAcceptStage( |
1397 |
Executor e, CompletionStage<U> o, Consumer<? super T> f) { |
1398 |
CompletableFuture<U> b; |
1399 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1400 |
throw new NullPointerException(); |
1401 |
CompletableFuture<Void> d = new CompletableFuture<Void>(); |
1402 |
if (e != null || !d.orAccept(this, b, f, null)) { |
1403 |
OrAccept<T,U> c = new OrAccept<T,U>(e, d, this, b, f); |
1404 |
orpush(b, c); |
1405 |
c.tryFire(SYNC); |
1406 |
} |
1407 |
return d; |
1408 |
} |
1409 |
|
1410 |
@SuppressWarnings("serial") |
1411 |
static final class OrRun<T,U> extends BiCompletion<T,U,Void> { |
1412 |
Runnable fn; |
1413 |
OrRun(Executor executor, CompletableFuture<Void> dep, |
1414 |
CompletableFuture<T> src, |
1415 |
CompletableFuture<U> snd, |
1416 |
Runnable fn) { |
1417 |
super(executor, dep, src, snd); this.fn = fn; |
1418 |
} |
1419 |
final CompletableFuture<Void> tryFire(int mode) { |
1420 |
CompletableFuture<Void> d; |
1421 |
CompletableFuture<T> a; |
1422 |
CompletableFuture<U> b; |
1423 |
if ((d = dep) == null || |
1424 |
!d.orRun(a = src, b = snd, fn, mode > 0 ? null : this)) |
1425 |
return null; |
1426 |
dep = null; src = null; snd = null; fn = null; |
1427 |
return d.postFire(a, b, mode); |
1428 |
} |
1429 |
} |
1430 |
|
1431 |
final boolean orRun(CompletableFuture<?> a, CompletableFuture<?> b, |
1432 |
Runnable f, OrRun<?,?> c) { |
1433 |
Object r; Throwable x; |
1434 |
if (a == null || b == null || |
1435 |
((r = a.result) == null && (r = b.result) == null) || f == null) |
1436 |
return false; |
1437 |
if (result == null) { |
1438 |
try { |
1439 |
if (c != null && !c.claim()) |
1440 |
return false; |
1441 |
if (r instanceof AltResult && (x = ((AltResult)r).ex) != null) |
1442 |
completeThrowable(x, r); |
1443 |
else { |
1444 |
f.run(); |
1445 |
completeNull(); |
1446 |
} |
1447 |
} catch (Throwable ex) { |
1448 |
completeThrowable(ex); |
1449 |
} |
1450 |
} |
1451 |
return true; |
1452 |
} |
1453 |
|
1454 |
private CompletableFuture<Void> orRunStage(Executor e, CompletionStage<?> o, |
1455 |
Runnable f) { |
1456 |
CompletableFuture<?> b; |
1457 |
if (f == null || (b = o.toCompletableFuture()) == null) |
1458 |
throw new NullPointerException(); |
1459 |
CompletableFuture<Void> d = new CompletableFuture<Void>(); |
1460 |
if (e != null || !d.orRun(this, b, f, null)) { |
1461 |
OrRun<T,?> c = new OrRun<>(e, d, this, b, f); |
1462 |
orpush(b, c); |
1463 |
c.tryFire(SYNC); |
1464 |
} |
1465 |
return d; |
1466 |
} |
1467 |
|
1468 |
@SuppressWarnings("serial") |
1469 |
static final class OrRelay<T,U> extends BiCompletion<T,U,Object> { // for Or |
1470 |
OrRelay(CompletableFuture<Object> dep, CompletableFuture<T> src, |
1471 |
CompletableFuture<U> snd) { |
1472 |
super(null, dep, src, snd); |
1473 |
} |
1474 |
final CompletableFuture<Object> tryFire(int mode) { |
1475 |
CompletableFuture<Object> d; |
1476 |
CompletableFuture<T> a; |
1477 |
CompletableFuture<U> b; |
1478 |
if ((d = dep) == null || !d.orRelay(a = src, b = snd)) |
1479 |
return null; |
1480 |
src = null; snd = null; dep = null; |
1481 |
return d.postFire(a, b, mode); |
1482 |
} |
1483 |
} |
1484 |
|
1485 |
final boolean orRelay(CompletableFuture<?> a, CompletableFuture<?> b) { |
1486 |
Object r; |
1487 |
if (a == null || b == null || |
1488 |
((r = a.result) == null && (r = b.result) == null)) |
1489 |
return false; |
1490 |
if (result == null) |
1491 |
completeRelay(r); |
1492 |
return true; |
1493 |
} |
1494 |
|
1495 |
/** Recursively constructs a tree of completions. */ |
1496 |
static CompletableFuture<Object> orTree(CompletableFuture<?>[] cfs, |
1497 |
int lo, int hi) { |
1498 |
CompletableFuture<Object> d = new CompletableFuture<Object>(); |
1499 |
if (lo <= hi) { |
1500 |
CompletableFuture<?> a, b; |
1501 |
int mid = (lo + hi) >>> 1; |
1502 |
if ((a = (lo == mid ? cfs[lo] : |
1503 |
orTree(cfs, lo, mid))) == null || |
1504 |
(b = (lo == hi ? a : (hi == mid+1) ? cfs[hi] : |
1505 |
orTree(cfs, mid+1, hi))) == null) |
1506 |
throw new NullPointerException(); |
1507 |
if (!d.orRelay(a, b)) { |
1508 |
OrRelay<?,?> c = new OrRelay<>(d, a, b); |
1509 |
a.orpush(b, c); |
1510 |
c.tryFire(SYNC); |
1511 |
} |
1512 |
} |
1513 |
return d; |
1514 |
} |
1515 |
|
1516 |
/* ------------- Zero-input Async forms -------------- */ |
1517 |
|
1518 |
@SuppressWarnings("serial") |
1519 |
static final class AsyncSupply<T> extends Completion { |
1520 |
CompletableFuture<T> dep; Supplier<T> fn; |
1521 |
AsyncSupply(CompletableFuture<T> dep, Supplier<T> fn) { |
1522 |
this.dep = dep; this.fn = fn; |
1523 |
} |
1524 |
|
1525 |
final CompletableFuture<T> tryFire(int alwaysAsync) { |
1526 |
// assert alwaysAsync == ASYNC; |
1527 |
CompletableFuture<T> d; Supplier<T> f; |
1528 |
if ((d = dep) != null && (f = fn) != null) { |
1529 |
dep = null; fn = null; |
1530 |
if (d.result == null) { |
1531 |
try { |
1532 |
d.completeValue(f.get()); |
1533 |
} catch (Throwable ex) { |
1534 |
d.completeThrowable(ex); |
1535 |
} |
1536 |
} |
1537 |
d.postComplete(); |
1538 |
} |
1539 |
return d; |
1540 |
} |
1541 |
final boolean isLive() { return dep != null; } |
1542 |
} |
1543 |
|
1544 |
static <U> CompletableFuture<U> asyncSupplyStage(Executor e, |
1545 |
Supplier<U> f) { |
1546 |
if (f == null) throw new NullPointerException(); |
1547 |
CompletableFuture<U> d = new CompletableFuture<U>(); |
1548 |
e.execute(new AsyncSupply<U>(d, f)); |
1549 |
return d; |
1550 |
} |
1551 |
|
1552 |
@SuppressWarnings("serial") |
1553 |
static final class AsyncRun extends Completion { |
1554 |
CompletableFuture<Void> dep; Runnable fn; |
1555 |
AsyncRun(CompletableFuture<Void> dep, Runnable fn) { |
1556 |
this.dep = dep; this.fn = fn; |
1557 |
} |
1558 |
|
1559 |
final CompletableFuture<Void> tryFire(int alwaysAsync) { |
1560 |
// assert alwaysAsync == ASYNC; |
1561 |
CompletableFuture<Void> d; Runnable f; |
1562 |
if ((d = dep) != null && (f = fn) != null) { |
1563 |
dep = null; fn = null; |
1564 |
if (d.result == null) { |
1565 |
try { |
1566 |
f.run(); |
1567 |
d.completeNull(); |
1568 |
} catch (Throwable ex) { |
1569 |
d.completeThrowable(ex); |
1570 |
} |
1571 |
} |
1572 |
d.postComplete(); |
1573 |
} |
1574 |
return d; |
1575 |
} |
1576 |
final boolean isLive() { return dep != null; } |
1577 |
} |
1578 |
|
1579 |
static CompletableFuture<Void> asyncRunStage(Executor e, Runnable f) { |
1580 |
if (f == null) throw new NullPointerException(); |
1581 |
CompletableFuture<Void> d = new CompletableFuture<Void>(); |
1582 |
e.execute(new AsyncRun(d, f)); |
1583 |
return d; |
1584 |
} |
1585 |
|
1586 |
/* ------------- Signallers -------------- */ |
1587 |
|
1588 |
/** |
1589 |
* Completion for recording and releasing a waiting thread. This |
1590 |
* class implements ManagedBlocker to avoid starvation when |
1591 |
* blocking actions pile up in ForkJoinPools. |
1592 |
*/ |
1593 |
@SuppressWarnings("serial") |
1594 |
static final class Signaller extends Completion |
1595 |
implements ForkJoinPool.ManagedBlocker { |
1596 |
long nanos; // wait time if timed |
1597 |
final long deadline; // non-zero if timed |
1598 |
volatile int interruptControl; // > 0: interruptible, < 0: interrupted |
1599 |
volatile Thread thread; |
1600 |
|
1601 |
Signaller(boolean interruptible, long nanos, long deadline) { |
1602 |
this.thread = Thread.currentThread(); |
1603 |
this.interruptControl = interruptible ? 1 : 0; |
1604 |
this.nanos = nanos; |
1605 |
this.deadline = deadline; |
1606 |
} |
1607 |
final CompletableFuture<?> tryFire(int ignore) { |
1608 |
Thread w; // no need to atomically claim |
1609 |
if ((w = thread) != null) { |
1610 |
thread = null; |
1611 |
LockSupport.unpark(w); |
1612 |
} |
1613 |
return null; |
1614 |
} |
1615 |
public boolean isReleasable() { |
1616 |
if (thread == null) |
1617 |
return true; |
1618 |
if (Thread.interrupted()) { |
1619 |
int i = interruptControl; |
1620 |
interruptControl = -1; |
1621 |
if (i > 0) |
1622 |
return true; |
1623 |
} |
1624 |
if (deadline != 0L && |
1625 |
(nanos <= 0L || (nanos = deadline - System.nanoTime()) <= 0L)) { |
1626 |
thread = null; |
1627 |
return true; |
1628 |
} |
1629 |
return false; |
1630 |
} |
1631 |
public boolean block() { |
1632 |
if (isReleasable()) |
1633 |
return true; |
1634 |
else if (deadline == 0L) |
1635 |
LockSupport.park(this); |
1636 |
else if (nanos > 0L) |
1637 |
LockSupport.parkNanos(this, nanos); |
1638 |
return isReleasable(); |
1639 |
} |
1640 |
final boolean isLive() { return thread != null; } |
1641 |
} |
1642 |
|
1643 |
/** |
1644 |
* Returns raw result after waiting, or null if interruptible and |
1645 |
* interrupted. |
1646 |
*/ |
1647 |
private Object waitingGet(boolean interruptible) { |
1648 |
Signaller q = null; |
1649 |
boolean queued = false; |
1650 |
int spins = -1; |
1651 |
Object r; |
1652 |
while ((r = result) == null) { |
1653 |
if (spins < 0) |
1654 |
spins = (Runtime.getRuntime().availableProcessors() > 1) ? |
1655 |
1 << 8 : 0; // Use brief spin-wait on multiprocessors |
1656 |
else if (spins > 0) { |
1657 |
if (ThreadLocalRandom.nextSecondarySeed() >= 0) |
1658 |
--spins; |
1659 |
} |
1660 |
else if (q == null) |
1661 |
q = new Signaller(interruptible, 0L, 0L); |
1662 |
else if (!queued) |
1663 |
queued = casStack(q.next = stack, q); |
1664 |
else if (interruptible && q.interruptControl < 0) { |
1665 |
q.thread = null; |
1666 |
cleanStack(); |
1667 |
return null; |
1668 |
} |
1669 |
else if (q.thread != null && result == null) { |
1670 |
try { |
1671 |
ForkJoinPool.managedBlock(q); |
1672 |
} catch (InterruptedException ie) { |
1673 |
q.interruptControl = -1; |
1674 |
} |
1675 |
} |
1676 |
} |
1677 |
if (q != null) { |
1678 |
q.thread = null; |
1679 |
if (q.interruptControl < 0) { |
1680 |
if (interruptible) |
1681 |
r = null; // report interruption |
1682 |
else |
1683 |
Thread.currentThread().interrupt(); |
1684 |
} |
1685 |
} |
1686 |
postComplete(); |
1687 |
return r; |
1688 |
} |
1689 |
|
1690 |
/** |
1691 |
* Returns raw result after waiting, or null if interrupted, or |
1692 |
* throws TimeoutException on timeout. |
1693 |
*/ |
1694 |
private Object timedGet(long nanos) throws TimeoutException { |
1695 |
if (Thread.interrupted()) |
1696 |
return null; |
1697 |
if (nanos <= 0L) |
1698 |
throw new TimeoutException(); |
1699 |
long d = System.nanoTime() + nanos; |
1700 |
Signaller q = new Signaller(true, nanos, d == 0L ? 1L : d); // avoid 0 |
1701 |
boolean queued = false; |
1702 |
Object r; |
1703 |
while ((r = result) == null) { |
1704 |
if (!queued) |
1705 |
queued = casStack(q.next = stack, q); |
1706 |
else if (q.interruptControl < 0 || q.nanos <= 0L) { |
1707 |
q.thread = null; |
1708 |
cleanStack(); |
1709 |
if (q.interruptControl < 0) |
1710 |
return null; |
1711 |
throw new TimeoutException(); |
1712 |
} |
1713 |
else if (q.thread != null && result == null) { |
1714 |
try { |
1715 |
ForkJoinPool.managedBlock(q); |
1716 |
} catch (InterruptedException ie) { |
1717 |
q.interruptControl = -1; |
1718 |
} |
1719 |
} |
1720 |
} |
1721 |
if (q.interruptControl < 0) |
1722 |
r = null; |
1723 |
q.thread = null; |
1724 |
postComplete(); |
1725 |
return r; |
1726 |
} |
1727 |
|
1728 |
/* ------------- public methods -------------- */ |
1729 |
|
1730 |
/** |
1731 |
* Creates a new incomplete CompletableFuture. |
1732 |
*/ |
1733 |
public CompletableFuture() { |
1734 |
} |
1735 |
|
1736 |
/** |
1737 |
* Creates a new complete CompletableFuture with given encoded result. |
1738 |
*/ |
1739 |
private CompletableFuture(Object r) { |
1740 |
this.result = r; |
1741 |
} |
1742 |
|
1743 |
/** |
1744 |
* Returns a new CompletableFuture that is asynchronously completed |
1745 |
* by a task running in the {@link ForkJoinPool#commonPool()} with |
1746 |
* the value obtained by calling the given Supplier. |
1747 |
* |
1748 |
* @param supplier a function returning the value to be used |
1749 |
* to complete the returned CompletableFuture |
1750 |
* @param <U> the function's return type |
1751 |
* @return the new CompletableFuture |
1752 |
*/ |
1753 |
public static <U> CompletableFuture<U> supplyAsync(Supplier<U> supplier) { |
1754 |
return asyncSupplyStage(asyncPool, supplier); |
1755 |
} |
1756 |
|
1757 |
/** |
1758 |
* Returns a new CompletableFuture that is asynchronously completed |
1759 |
* by a task running in the given executor with the value obtained |
1760 |
* by calling the given Supplier. |
1761 |
* |
1762 |
* @param supplier a function returning the value to be used |
1763 |
* to complete the returned CompletableFuture |
1764 |
* @param executor the executor to use for asynchronous execution |
1765 |
* @param <U> the function's return type |
1766 |
* @return the new CompletableFuture |
1767 |
*/ |
1768 |
public static <U> CompletableFuture<U> supplyAsync(Supplier<U> supplier, |
1769 |
Executor executor) { |
1770 |
return asyncSupplyStage(screenExecutor(executor), supplier); |
1771 |
} |
1772 |
|
1773 |
/** |
1774 |
* Returns a new CompletableFuture that is asynchronously completed |
1775 |
* by a task running in the {@link ForkJoinPool#commonPool()} after |
1776 |
* it runs the given action. |
1777 |
* |
1778 |
* @param runnable the action to run before completing the |
1779 |
* returned CompletableFuture |
1780 |
* @return the new CompletableFuture |
1781 |
*/ |
1782 |
public static CompletableFuture<Void> runAsync(Runnable runnable) { |
1783 |
return asyncRunStage(asyncPool, runnable); |
1784 |
} |
1785 |
|
1786 |
/** |
1787 |
* Returns a new CompletableFuture that is asynchronously completed |
1788 |
* by a task running in the given executor after it runs the given |
1789 |
* action. |
1790 |
* |
1791 |
* @param runnable the action to run before completing the |
1792 |
* returned CompletableFuture |
1793 |
* @param executor the executor to use for asynchronous execution |
1794 |
* @return the new CompletableFuture |
1795 |
*/ |
1796 |
public static CompletableFuture<Void> runAsync(Runnable runnable, |
1797 |
Executor executor) { |
1798 |
return asyncRunStage(screenExecutor(executor), runnable); |
1799 |
} |
1800 |
|
1801 |
/** |
1802 |
* Returns a new CompletableFuture that is already completed with |
1803 |
* the given value. |
1804 |
* |
1805 |
* @param value the value |
1806 |
* @param <U> the type of the value |
1807 |
* @return the completed CompletableFuture |
1808 |
*/ |
1809 |
public static <U> CompletableFuture<U> completedFuture(U value) { |
1810 |
return new CompletableFuture<U>((value == null) ? NIL : value); |
1811 |
} |
1812 |
|
1813 |
/** |
1814 |
* Returns {@code true} if completed in any fashion: normally, |
1815 |
* exceptionally, or via cancellation. |
1816 |
* |
1817 |
* @return {@code true} if completed |
1818 |
*/ |
1819 |
public boolean isDone() { |
1820 |
return result != null; |
1821 |
} |
1822 |
|
1823 |
/** |
1824 |
* Waits if necessary for this future to complete, and then |
1825 |
* returns its result. |
1826 |
* |
1827 |
* @return the result value |
1828 |
* @throws CancellationException if this future was cancelled |
1829 |
* @throws ExecutionException if this future completed exceptionally |
1830 |
* @throws InterruptedException if the current thread was interrupted |
1831 |
* while waiting |
1832 |
*/ |
1833 |
public T get() throws InterruptedException, ExecutionException { |
1834 |
Object r; |
1835 |
return reportGet((r = result) == null ? waitingGet(true) : r); |
1836 |
} |
1837 |
|
1838 |
/** |
1839 |
* Waits if necessary for at most the given time for this future |
1840 |
* to complete, and then returns its result, if available. |
1841 |
* |
1842 |
* @param timeout the maximum time to wait |
1843 |
* @param unit the time unit of the timeout argument |
1844 |
* @return the result value |
1845 |
* @throws CancellationException if this future was cancelled |
1846 |
* @throws ExecutionException if this future completed exceptionally |
1847 |
* @throws InterruptedException if the current thread was interrupted |
1848 |
* while waiting |
1849 |
* @throws TimeoutException if the wait timed out |
1850 |
*/ |
1851 |
public T get(long timeout, TimeUnit unit) |
1852 |
throws InterruptedException, ExecutionException, TimeoutException { |
1853 |
Object r; |
1854 |
long nanos = unit.toNanos(timeout); |
1855 |
return reportGet((r = result) == null ? timedGet(nanos) : r); |
1856 |
} |
1857 |
|
1858 |
/** |
1859 |
* Returns the result value when complete, or throws an |
1860 |
* (unchecked) exception if completed exceptionally. To better |
1861 |
* conform with the use of common functional forms, if a |
1862 |
* computation involved in the completion of this |
1863 |
* CompletableFuture threw an exception, this method throws an |
1864 |
* (unchecked) {@link CompletionException} with the underlying |
1865 |
* exception as its cause. |
1866 |
* |
1867 |
* @return the result value |
1868 |
* @throws CancellationException if the computation was cancelled |
1869 |
* @throws CompletionException if this future completed |
1870 |
* exceptionally or a completion computation threw an exception |
1871 |
*/ |
1872 |
public T join() { |
1873 |
Object r; |
1874 |
return reportJoin((r = result) == null ? waitingGet(false) : r); |
1875 |
} |
1876 |
|
1877 |
/** |
1878 |
* Returns the result value (or throws any encountered exception) |
1879 |
* if completed, else returns the given valueIfAbsent. |
1880 |
* |
1881 |
* @param valueIfAbsent the value to return if not completed |
1882 |
* @return the result value, if completed, else the given valueIfAbsent |
1883 |
* @throws CancellationException if the computation was cancelled |
1884 |
* @throws CompletionException if this future completed |
1885 |
* exceptionally or a completion computation threw an exception |
1886 |
*/ |
1887 |
public T getNow(T valueIfAbsent) { |
1888 |
Object r; |
1889 |
return ((r = result) == null) ? valueIfAbsent : reportJoin(r); |
1890 |
} |
1891 |
|
1892 |
/** |
1893 |
* If not already completed, sets the value returned by {@link |
1894 |
* #get()} and related methods to the given value. |
1895 |
* |
1896 |
* @param value the result value |
1897 |
* @return {@code true} if this invocation caused this CompletableFuture |
1898 |
* to transition to a completed state, else {@code false} |
1899 |
*/ |
1900 |
public boolean complete(T value) { |
1901 |
boolean triggered = completeValue(value); |
1902 |
postComplete(); |
1903 |
return triggered; |
1904 |
} |
1905 |
|
1906 |
/** |
1907 |
* If not already completed, causes invocations of {@link #get()} |
1908 |
* and related methods to throw the given exception. |
1909 |
* |
1910 |
* @param ex the exception |
1911 |
* @return {@code true} if this invocation caused this CompletableFuture |
1912 |
* to transition to a completed state, else {@code false} |
1913 |
*/ |
1914 |
public boolean completeExceptionally(Throwable ex) { |
1915 |
if (ex == null) throw new NullPointerException(); |
1916 |
boolean triggered = internalComplete(new AltResult(ex)); |
1917 |
postComplete(); |
1918 |
return triggered; |
1919 |
} |
1920 |
|
1921 |
public <U> CompletableFuture<U> thenApply( |
1922 |
Function<? super T,? extends U> fn) { |
1923 |
return uniApplyStage(null, fn); |
1924 |
} |
1925 |
|
1926 |
public <U> CompletableFuture<U> thenApplyAsync( |
1927 |
Function<? super T,? extends U> fn) { |
1928 |
return uniApplyStage(asyncPool, fn); |
1929 |
} |
1930 |
|
1931 |
public <U> CompletableFuture<U> thenApplyAsync( |
1932 |
Function<? super T,? extends U> fn, Executor executor) { |
1933 |
return uniApplyStage(screenExecutor(executor), fn); |
1934 |
} |
1935 |
|
1936 |
public CompletableFuture<Void> thenAccept(Consumer<? super T> action) { |
1937 |
return uniAcceptStage(null, action); |
1938 |
} |
1939 |
|
1940 |
public CompletableFuture<Void> thenAcceptAsync(Consumer<? super T> action) { |
1941 |
return uniAcceptStage(asyncPool, action); |
1942 |
} |
1943 |
|
1944 |
public CompletableFuture<Void> thenAcceptAsync(Consumer<? super T> action, |
1945 |
Executor executor) { |
1946 |
return uniAcceptStage(screenExecutor(executor), action); |
1947 |
} |
1948 |
|
1949 |
public CompletableFuture<Void> thenRun(Runnable action) { |
1950 |
return uniRunStage(null, action); |
1951 |
} |
1952 |
|
1953 |
public CompletableFuture<Void> thenRunAsync(Runnable action) { |
1954 |
return uniRunStage(asyncPool, action); |
1955 |
} |
1956 |
|
1957 |
public CompletableFuture<Void> thenRunAsync(Runnable action, |
1958 |
Executor executor) { |
1959 |
return uniRunStage(screenExecutor(executor), action); |
1960 |
} |
1961 |
|
1962 |
public <U,V> CompletableFuture<V> thenCombine( |
1963 |
CompletionStage<? extends U> other, |
1964 |
BiFunction<? super T,? super U,? extends V> fn) { |
1965 |
return biApplyStage(null, other, fn); |
1966 |
} |
1967 |
|
1968 |
public <U,V> CompletableFuture<V> thenCombineAsync( |
1969 |
CompletionStage<? extends U> other, |
1970 |
BiFunction<? super T,? super U,? extends V> fn) { |
1971 |
return biApplyStage(asyncPool, other, fn); |
1972 |
} |
1973 |
|
1974 |
public <U,V> CompletableFuture<V> thenCombineAsync( |
1975 |
CompletionStage<? extends U> other, |
1976 |
BiFunction<? super T,? super U,? extends V> fn, Executor executor) { |
1977 |
return biApplyStage(screenExecutor(executor), other, fn); |
1978 |
} |
1979 |
|
1980 |
public <U> CompletableFuture<Void> thenAcceptBoth( |
1981 |
CompletionStage<? extends U> other, |
1982 |
BiConsumer<? super T, ? super U> action) { |
1983 |
return biAcceptStage(null, other, action); |
1984 |
} |
1985 |
|
1986 |
public <U> CompletableFuture<Void> thenAcceptBothAsync( |
1987 |
CompletionStage<? extends U> other, |
1988 |
BiConsumer<? super T, ? super U> action) { |
1989 |
return biAcceptStage(asyncPool, other, action); |
1990 |
} |
1991 |
|
1992 |
public <U> CompletableFuture<Void> thenAcceptBothAsync( |
1993 |
CompletionStage<? extends U> other, |
1994 |
BiConsumer<? super T, ? super U> action, Executor executor) { |
1995 |
return biAcceptStage(screenExecutor(executor), other, action); |
1996 |
} |
1997 |
|
1998 |
public CompletableFuture<Void> runAfterBoth(CompletionStage<?> other, |
1999 |
Runnable action) { |
2000 |
return biRunStage(null, other, action); |
2001 |
} |
2002 |
|
2003 |
public CompletableFuture<Void> runAfterBothAsync(CompletionStage<?> other, |
2004 |
Runnable action) { |
2005 |
return biRunStage(asyncPool, other, action); |
2006 |
} |
2007 |
|
2008 |
public CompletableFuture<Void> runAfterBothAsync(CompletionStage<?> other, |
2009 |
Runnable action, |
2010 |
Executor executor) { |
2011 |
return biRunStage(screenExecutor(executor), other, action); |
2012 |
} |
2013 |
|
2014 |
public <U> CompletableFuture<U> applyToEither( |
2015 |
CompletionStage<? extends T> other, Function<? super T, U> fn) { |
2016 |
return orApplyStage(null, other, fn); |
2017 |
} |
2018 |
|
2019 |
public <U> CompletableFuture<U> applyToEitherAsync( |
2020 |
CompletionStage<? extends T> other, Function<? super T, U> fn) { |
2021 |
return orApplyStage(asyncPool, other, fn); |
2022 |
} |
2023 |
|
2024 |
public <U> CompletableFuture<U> applyToEitherAsync( |
2025 |
CompletionStage<? extends T> other, Function<? super T, U> fn, |
2026 |
Executor executor) { |
2027 |
return orApplyStage(screenExecutor(executor), other, fn); |
2028 |
} |
2029 |
|
2030 |
public CompletableFuture<Void> acceptEither( |
2031 |
CompletionStage<? extends T> other, Consumer<? super T> action) { |
2032 |
return orAcceptStage(null, other, action); |
2033 |
} |
2034 |
|
2035 |
public CompletableFuture<Void> acceptEitherAsync( |
2036 |
CompletionStage<? extends T> other, Consumer<? super T> action) { |
2037 |
return orAcceptStage(asyncPool, other, action); |
2038 |
} |
2039 |
|
2040 |
public CompletableFuture<Void> acceptEitherAsync( |
2041 |
CompletionStage<? extends T> other, Consumer<? super T> action, |
2042 |
Executor executor) { |
2043 |
return orAcceptStage(screenExecutor(executor), other, action); |
2044 |
} |
2045 |
|
2046 |
public CompletableFuture<Void> runAfterEither(CompletionStage<?> other, |
2047 |
Runnable action) { |
2048 |
return orRunStage(null, other, action); |
2049 |
} |
2050 |
|
2051 |
public CompletableFuture<Void> runAfterEitherAsync(CompletionStage<?> other, |
2052 |
Runnable action) { |
2053 |
return orRunStage(asyncPool, other, action); |
2054 |
} |
2055 |
|
2056 |
public CompletableFuture<Void> runAfterEitherAsync(CompletionStage<?> other, |
2057 |
Runnable action, |
2058 |
Executor executor) { |
2059 |
return orRunStage(screenExecutor(executor), other, action); |
2060 |
} |
2061 |
|
2062 |
public <U> CompletableFuture<U> thenCompose( |
2063 |
Function<? super T, ? extends CompletionStage<U>> fn) { |
2064 |
return uniComposeStage(null, fn); |
2065 |
} |
2066 |
|
2067 |
public <U> CompletableFuture<U> thenComposeAsync( |
2068 |
Function<? super T, ? extends CompletionStage<U>> fn) { |
2069 |
return uniComposeStage(asyncPool, fn); |
2070 |
} |
2071 |
|
2072 |
public <U> CompletableFuture<U> thenComposeAsync( |
2073 |
Function<? super T, ? extends CompletionStage<U>> fn, |
2074 |
Executor executor) { |
2075 |
return uniComposeStage(screenExecutor(executor), fn); |
2076 |
} |
2077 |
|
2078 |
public CompletableFuture<T> whenComplete( |
2079 |
BiConsumer<? super T, ? super Throwable> action) { |
2080 |
return uniWhenCompleteStage(null, action); |
2081 |
} |
2082 |
|
2083 |
public CompletableFuture<T> whenCompleteAsync( |
2084 |
BiConsumer<? super T, ? super Throwable> action) { |
2085 |
return uniWhenCompleteStage(asyncPool, action); |
2086 |
} |
2087 |
|
2088 |
public CompletableFuture<T> whenCompleteAsync( |
2089 |
BiConsumer<? super T, ? super Throwable> action, Executor executor) { |
2090 |
return uniWhenCompleteStage(screenExecutor(executor), action); |
2091 |
} |
2092 |
|
2093 |
public <U> CompletableFuture<U> handle( |
2094 |
BiFunction<? super T, Throwable, ? extends U> fn) { |
2095 |
return uniHandleStage(null, fn); |
2096 |
} |
2097 |
|
2098 |
public <U> CompletableFuture<U> handleAsync( |
2099 |
BiFunction<? super T, Throwable, ? extends U> fn) { |
2100 |
return uniHandleStage(asyncPool, fn); |
2101 |
} |
2102 |
|
2103 |
public <U> CompletableFuture<U> handleAsync( |
2104 |
BiFunction<? super T, Throwable, ? extends U> fn, Executor executor) { |
2105 |
return uniHandleStage(screenExecutor(executor), fn); |
2106 |
} |
2107 |
|
2108 |
/** |
2109 |
* Returns this CompletableFuture. |
2110 |
* |
2111 |
* @return this CompletableFuture |
2112 |
*/ |
2113 |
public CompletableFuture<T> toCompletableFuture() { |
2114 |
return this; |
2115 |
} |
2116 |
|
2117 |
// not in interface CompletionStage |
2118 |
|
2119 |
/** |
2120 |
* Returns a new CompletableFuture that is completed when this |
2121 |
* CompletableFuture completes, with the result of the given |
2122 |
* function of the exception triggering this CompletableFuture's |
2123 |
* completion when it completes exceptionally; otherwise, if this |
2124 |
* CompletableFuture completes normally, then the returned |
2125 |
* CompletableFuture also completes normally with the same value. |
2126 |
* Note: More flexible versions of this functionality are |
2127 |
* available using methods {@code whenComplete} and {@code handle}. |
2128 |
* |
2129 |
* @param fn the function to use to compute the value of the |
2130 |
* returned CompletableFuture if this CompletableFuture completed |
2131 |
* exceptionally |
2132 |
* @return the new CompletableFuture |
2133 |
*/ |
2134 |
public CompletableFuture<T> exceptionally( |
2135 |
Function<Throwable, ? extends T> fn) { |
2136 |
return uniExceptionallyStage(fn); |
2137 |
} |
2138 |
|
2139 |
/* ------------- Arbitrary-arity constructions -------------- */ |
2140 |
|
2141 |
/** |
2142 |
* Returns a new CompletableFuture that is completed when all of |
2143 |
* the given CompletableFutures complete. If any of the given |
2144 |
* CompletableFutures complete exceptionally, then the returned |
2145 |
* CompletableFuture also does so, with a CompletionException |
2146 |
* holding this exception as its cause. Otherwise, the results, |
2147 |
* if any, of the given CompletableFutures are not reflected in |
2148 |
* the returned CompletableFuture, but may be obtained by |
2149 |
* inspecting them individually. If no CompletableFutures are |
2150 |
* provided, returns a CompletableFuture completed with the value |
2151 |
* {@code null}. |
2152 |
* |
2153 |
* <p>Among the applications of this method is to await completion |
2154 |
* of a set of independent CompletableFutures before continuing a |
2155 |
* program, as in: {@code CompletableFuture.allOf(c1, c2, |
2156 |
* c3).join();}. |
2157 |
* |
2158 |
* @param cfs the CompletableFutures |
2159 |
* @return a new CompletableFuture that is completed when all of the |
2160 |
* given CompletableFutures complete |
2161 |
* @throws NullPointerException if the array or any of its elements are |
2162 |
* {@code null} |
2163 |
*/ |
2164 |
public static CompletableFuture<Void> allOf(CompletableFuture<?>... cfs) { |
2165 |
return andTree(cfs, 0, cfs.length - 1); |
2166 |
} |
2167 |
|
2168 |
/** |
2169 |
* Returns a new CompletableFuture that is completed when any of |
2170 |
* the given CompletableFutures complete, with the same result. |
2171 |
* Otherwise, if it completed exceptionally, the returned |
2172 |
* CompletableFuture also does so, with a CompletionException |
2173 |
* holding this exception as its cause. If no CompletableFutures |
2174 |
* are provided, returns an incomplete CompletableFuture. |
2175 |
* |
2176 |
* @param cfs the CompletableFutures |
2177 |
* @return a new CompletableFuture that is completed with the |
2178 |
* result or exception of any of the given CompletableFutures when |
2179 |
* one completes |
2180 |
* @throws NullPointerException if the array or any of its elements are |
2181 |
* {@code null} |
2182 |
*/ |
2183 |
public static CompletableFuture<Object> anyOf(CompletableFuture<?>... cfs) { |
2184 |
return orTree(cfs, 0, cfs.length - 1); |
2185 |
} |
2186 |
|
2187 |
/* ------------- Control and status methods -------------- */ |
2188 |
|
2189 |
/** |
2190 |
* If not already completed, completes this CompletableFuture with |
2191 |
* a {@link CancellationException}. Dependent CompletableFutures |
2192 |
* that have not already completed will also complete |
2193 |
* exceptionally, with a {@link CompletionException} caused by |
2194 |
* this {@code CancellationException}. |
2195 |
* |
2196 |
* @param mayInterruptIfRunning this value has no effect in this |
2197 |
* implementation because interrupts are not used to control |
2198 |
* processing. |
2199 |
* |
2200 |
* @return {@code true} if this task is now cancelled |
2201 |
*/ |
2202 |
public boolean cancel(boolean mayInterruptIfRunning) { |
2203 |
boolean cancelled = (result == null) && |
2204 |
internalComplete(new AltResult(new CancellationException())); |
2205 |
postComplete(); |
2206 |
return cancelled || isCancelled(); |
2207 |
} |
2208 |
|
2209 |
/** |
2210 |
* Returns {@code true} if this CompletableFuture was cancelled |
2211 |
* before it completed normally. |
2212 |
* |
2213 |
* @return {@code true} if this CompletableFuture was cancelled |
2214 |
* before it completed normally |
2215 |
*/ |
2216 |
public boolean isCancelled() { |
2217 |
Object r; |
2218 |
return ((r = result) instanceof AltResult) && |
2219 |
(((AltResult)r).ex instanceof CancellationException); |
2220 |
} |
2221 |
|
2222 |
/** |
2223 |
* Returns {@code true} if this CompletableFuture completed |
2224 |
* exceptionally, in any way. Possible causes include |
2225 |
* cancellation, explicit invocation of {@code |
2226 |
* completeExceptionally}, and abrupt termination of a |
2227 |
* CompletionStage action. |
2228 |
* |
2229 |
* @return {@code true} if this CompletableFuture completed |
2230 |
* exceptionally |
2231 |
*/ |
2232 |
public boolean isCompletedExceptionally() { |
2233 |
Object r; |
2234 |
return ((r = result) instanceof AltResult) && r != NIL; |
2235 |
} |
2236 |
|
2237 |
/** |
2238 |
* Forcibly sets or resets the value subsequently returned by |
2239 |
* method {@link #get()} and related methods, whether or not |
2240 |
* already completed. This method is designed for use only in |
2241 |
* error recovery actions, and even in such situations may result |
2242 |
* in ongoing dependent completions using established versus |
2243 |
* overwritten outcomes. |
2244 |
* |
2245 |
* @param value the completion value |
2246 |
*/ |
2247 |
public void obtrudeValue(T value) { |
2248 |
result = (value == null) ? NIL : value; |
2249 |
postComplete(); |
2250 |
} |
2251 |
|
2252 |
/** |
2253 |
* Forcibly causes subsequent invocations of method {@link #get()} |
2254 |
* and related methods to throw the given exception, whether or |
2255 |
* not already completed. This method is designed for use only in |
2256 |
* error recovery actions, and even in such situations may result |
2257 |
* in ongoing dependent completions using established versus |
2258 |
* overwritten outcomes. |
2259 |
* |
2260 |
* @param ex the exception |
2261 |
* @throws NullPointerException if the exception is null |
2262 |
*/ |
2263 |
public void obtrudeException(Throwable ex) { |
2264 |
if (ex == null) throw new NullPointerException(); |
2265 |
result = new AltResult(ex); |
2266 |
postComplete(); |
2267 |
} |
2268 |
|
2269 |
/** |
2270 |
* Returns the estimated number of CompletableFutures whose |
2271 |
* completions are awaiting completion of this CompletableFuture. |
2272 |
* This method is designed for use in monitoring system state, not |
2273 |
* for synchronization control. |
2274 |
* |
2275 |
* @return the number of dependent CompletableFutures |
2276 |
*/ |
2277 |
public int getNumberOfDependents() { |
2278 |
int count = 0; |
2279 |
for (Completion p = stack; p != null; p = p.next) |
2280 |
++count; |
2281 |
return count; |
2282 |
} |
2283 |
|
2284 |
/** |
2285 |
* Returns a string identifying this CompletableFuture, as well as |
2286 |
* its completion state. The state, in brackets, contains the |
2287 |
* String {@code "Completed Normally"} or the String {@code |
2288 |
* "Completed Exceptionally"}, or the String {@code "Not |
2289 |
* completed"} followed by the number of CompletableFutures |
2290 |
* dependent upon its completion, if any. |
2291 |
* |
2292 |
* @return a string identifying this CompletableFuture, as well as its state |
2293 |
*/ |
2294 |
public String toString() { |
2295 |
Object r = result; |
2296 |
int count; |
2297 |
return super.toString() + |
2298 |
((r == null) ? |
2299 |
(((count = getNumberOfDependents()) == 0) ? |
2300 |
"[Not completed]" : |
2301 |
"[Not completed, " + count + " dependents]") : |
2302 |
(((r instanceof AltResult) && ((AltResult)r).ex != null) ? |
2303 |
"[Completed exceptionally]" : |
2304 |
"[Completed normally]")); |
2305 |
} |
2306 |
|
2307 |
// Unsafe mechanics |
2308 |
private static final sun.misc.Unsafe UNSAFE; |
2309 |
private static final long RESULT; |
2310 |
private static final long STACK; |
2311 |
static { |
2312 |
try { |
2313 |
UNSAFE = sun.misc.Unsafe.getUnsafe(); |
2314 |
Class<?> k = CompletableFuture.class; |
2315 |
RESULT = UNSAFE.objectFieldOffset |
2316 |
(k.getDeclaredField("result")); |
2317 |
STACK = UNSAFE.objectFieldOffset |
2318 |
(k.getDeclaredField("stack")); |
2319 |
} catch (Exception x) { |
2320 |
throw new Error(x); |
2321 |
} |
2322 |
} |
2323 |
} |