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import java.util.concurrent.TimeUnit; |
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import java.util.concurrent.atomic.AtomicInteger; |
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import java.util.concurrent.atomic.AtomicLong; |
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import java.util.concurrent.locks.ReentrantLock; |
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import java.util.concurrent.locks.AbstractQueuedSynchronizer; |
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import java.util.concurrent.locks.Condition; |
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/** |
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* convenient form for informal monitoring. |
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* |
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* <p> As is the case with other ExecutorServices, there are three |
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* main task execution methods summarized in the following |
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* table. These are designed to be used primarily by clients not |
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* already engaged in fork/join computations in the current pool. The |
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* main forms of these methods accept instances of {@code |
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* ForkJoinTask}, but overloaded forms also allow mixed execution of |
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* plain {@code Runnable}- or {@code Callable}- based activities as |
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* well. However, tasks that are already executing in a pool should |
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* normally instead use the within-computation forms listed in the |
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* table unless using async event-style tasks that are not usually |
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* joined, in which case there is little difference among choice of |
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* methods. |
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* main task execution methods summarized in the following table. |
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* These are designed to be used primarily by clients not already |
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* engaged in fork/join computations in the current pool. The main |
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* forms of these methods accept instances of {@code ForkJoinTask}, |
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* but overloaded forms also allow mixed execution of plain {@code |
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* Runnable}- or {@code Callable}- based activities as well. However, |
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* tasks that are already executing in a pool should normally instead |
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* use the within-computation forms listed in the table unless using |
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* async event-style tasks that are not usually joined, in which case |
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* there is little difference among choice of methods. |
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* |
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* <table BORDER CELLPADDING=3 CELLSPACING=1> |
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* <tr> |
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* |
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* This class and its nested classes provide the main |
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* functionality and control for a set of worker threads: |
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* Submissions from non-FJ threads enter into submission |
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* queues. Workers take these tasks and typically split them into |
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* subtasks that may be stolen by other workers. Preference rules |
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* give first priority to processing tasks from their own queues |
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* (LIFO or FIFO, depending on mode), then to randomized FIFO |
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* steals of tasks in other queues. |
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* Submissions from non-FJ threads enter into submission queues. |
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* Workers take these tasks and typically split them into subtasks |
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* that may be stolen by other workers. Preference rules give |
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* first priority to processing tasks from their own queues (LIFO |
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* or FIFO, depending on mode), then to randomized FIFO steals of |
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* tasks in other queues. |
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* |
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* WorkQueues. |
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* WorkQueues |
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* ========== |
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* |
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* Most operations occur within work-stealing queues (in nested |
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* (http://research.sun.com/scalable/pubs/index.html) and |
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* "Idempotent work stealing" by Michael, Saraswat, and Vechev, |
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* PPoPP 2009 (http://portal.acm.org/citation.cfm?id=1504186). |
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* The main differences ultimately stem from gc requirements that |
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* The main differences ultimately stem from GC requirements that |
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* we null out taken slots as soon as we can, to maintain as small |
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* a footprint as possible even in programs generating huge |
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* numbers of tasks. To accomplish this, we shift the CAS |
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* rarely provide the best possible performance on a given |
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* machine, but portably provide good throughput by averaging over |
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* these factors. (Further, even if we did try to use such |
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* information, we do not usually have a basis for exploiting |
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* it. For example, some sets of tasks profit from cache |
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* affinities, but others are harmed by cache pollution effects.) |
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* information, we do not usually have a basis for exploiting it. |
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* For example, some sets of tasks profit from cache affinities, |
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* but others are harmed by cache pollution effects.) |
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* |
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* WorkQueues are also used in a similar way for tasks submitted |
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* to the pool. We cannot mix these tasks in the same queues used |
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* take tasks, and they are multiplexed on to a finite number of |
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* shared work queues. However, classes are set up so that future |
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* extensions could allow submitters to optionally help perform |
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* tasks as well. Pool submissions from internal workers are also |
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* allowed, but use randomized rather than thread-hashed queue |
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* indices to avoid imbalance. Insertion of tasks in shared mode |
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* requires a lock (mainly to protect in the case of resizing) but |
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* we use only a simple spinlock (using bits in field runState), |
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* because submitters encountering a busy queue try or create |
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* others so never block. |
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* tasks as well. Insertion of tasks in shared mode requires a |
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* lock (mainly to protect in the case of resizing) but we use |
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* only a simple spinlock (using bits in field runState), because |
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* submitters encountering a busy queue move on to try or create |
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* other queues, so never block. |
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* |
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* Management. |
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* Management |
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* ========== |
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* |
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* The main throughput advantages of work-stealing stem from |
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* tactic for avoiding bottlenecks is packing nearly all |
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* essentially atomic control state into two volatile variables |
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* that are by far most often read (not written) as status and |
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* consistency checks |
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* consistency checks. |
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* |
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* Field "ctl" contains 64 bits holding all the information needed |
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* to atomically decide to add, inactivate, enqueue (on an event |
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* deregister WorkQueues, as well as to enable shutdown. It is |
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* only modified under a lock (normally briefly held, but |
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* occasionally protecting allocations and resizings) but even |
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* when locked remains available to check consistency. |
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* when locked remains available to check consistency. An |
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* auxiliary field "growHints", also only modified under lock, |
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* contains a candidate index for the next WorkQueue and |
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* a mask for submission queue indices. |
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* |
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* Recording WorkQueues. WorkQueues are recorded in the |
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* "workQueues" array that is created upon pool construction and |
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* presized to hold twice #parallelism workers (which is unlikely |
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* to need further resizing during execution). But to avoid |
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* dealing with so many null slots, variable runState includes a |
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* mask for the nearest power of two that contains all current |
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* workers. All worker thread creation is on-demand, triggered by |
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* task submissions, replacement of terminated workers, and/or |
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* mask for the nearest power of two that contains all currently |
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* used indices. |
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* |
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* All worker thread creation is on-demand, triggered by task |
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* submissions, replacement of terminated workers, and/or |
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* compensation for blocked workers. However, all other support |
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* code is set up to work with other policies. To ensure that we |
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* do not hold on to worker references that would prevent GC, ALL |
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* both index-check and null-check the IDs. All such accesses |
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* ignore bad IDs by returning out early from what they are doing, |
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* since this can only be associated with termination, in which |
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* case it is OK to give up. |
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* |
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* All uses of the workQueues array check that it is non-null |
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* (even if previously non-null). This allows nulling during |
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* termination, which is currently not necessary, but remains an |
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* option for resource-revocation-based shutdown schemes. It also |
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* helps reduce JIT issuance of uncommon-trap code, which tends to |
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* case it is OK to give up. All uses of the workQueues array |
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* also check that it is non-null (even if previously |
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* non-null). This allows nulling during termination, which is |
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* currently not necessary, but remains an option for |
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* resource-revocation-based shutdown schemes. It also helps |
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* reduce JIT issuance of uncommon-trap code, which tends to |
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* unnecessarily complicate control flow in some methods. |
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* |
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* Event Queuing. Unlike HPC work-stealing frameworks, we cannot |
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* some other queued worker rather than itself, which has the same |
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* net effect. Because enqueued workers may actually be rescanning |
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* rather than waiting, we set and clear the "parker" field of |
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* Workqueues to reduce unnecessary calls to unpark. (This |
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* WorkQueues to reduce unnecessary calls to unpark. (This |
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* requires a secondary recheck to avoid missed signals.) Note |
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* the unusual conventions about Thread.interrupts surrounding |
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* parking and other blocking: Because interrupts are used solely |
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* terminating all workers after long periods of non-use. |
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* |
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* Shutdown and Termination. A call to shutdownNow atomically sets |
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* a runState bit and then (non-atomically) sets each workers |
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* a runState bit and then (non-atomically) sets each worker's |
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* runState status, cancels all unprocessed tasks, and wakes up |
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* all waiting workers. Detecting whether termination should |
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* commence after a non-abrupt shutdown() call requires more work |
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* indication but non-abrupt shutdown still requires a rechecking |
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* scan for any workers that are inactive but not queued. |
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* |
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* Joining Tasks. |
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* ============== |
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* Joining Tasks |
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* ============= |
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* |
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* Any of several actions may be taken when one worker is waiting |
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* to join a task stolen (or always held by) another. Because we |
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* to join a task stolen (or always held) by another. Because we |
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* are multiplexing many tasks on to a pool of workers, we can't |
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* just let them block (as in Thread.join). We also cannot just |
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* reassign the joiner's run-time stack with another and replace |
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* it later, which would be a form of "continuation", that even if |
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* possible is not necessarily a good idea since we sometimes need |
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* both an unblocked task and its continuation to |
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* progress. Instead we combine two tactics: |
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* both an unblocked task and its continuation to progress. |
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* Instead we combine two tactics: |
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* |
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* Helping: Arranging for the joiner to execute some task that it |
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* would be running if the steal had not occurred. |
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* (http://portal.acm.org/citation.cfm?id=155354). It differs in |
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* that: (1) We only maintain dependency links across workers upon |
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* steals, rather than use per-task bookkeeping. This sometimes |
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* requires a linear scan of workers array to locate stealers, but |
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* requires a linear scan of workQueues array to locate stealers, but |
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* often doesn't because stealers leave hints (that may become |
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* stale/wrong) of where to locate them. A stealHint is only a |
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* hint because a worker might have had multiple steals and the |
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* managed by ForkJoinPool, so are directly accessed. There is |
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* little point trying to reduce this, since any associated future |
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* changes in representations will need to be accompanied by |
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* algorithmic changes anyway. All together, these low-level |
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* implementation choices produce as much as a factor of 4 |
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* performance improvement compared to naive implementations, and |
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* enable the processing of billions of tasks per second, at the |
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* expense of some ugliness. |
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* |
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* Methods signalWork() and scan() are the main bottlenecks so are |
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* especially heavily micro-optimized/mangled. There are lots of |
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* inline assignments (of form "while ((local = field) != 0)") |
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* which are usually the simplest way to ensure the required read |
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* orderings (which are sometimes critical). This leads to a |
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* "C"-like style of listing declarations of these locals at the |
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* heads of methods or blocks. There are several occurrences of |
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* the unusual "do {} while (!cas...)" which is the simplest way |
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* to force an update of a CAS'ed variable. There are also other |
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* coding oddities that help some methods perform reasonably even |
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* when interpreted (not compiled). |
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* |
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* The order of declarations in this file is: (1) declarations of |
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* statics (2) fields (along with constants used when unpacking |
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* some of them), listed in an order that tends to reduce |
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* contention among them a bit under most JVMs; (3) nested |
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* classes; (4) internal control methods; (5) callbacks and other |
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* support for ForkJoinTask methods; (6) exported methods (plus a |
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* few little helpers); (7) static block initializing all statics |
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* in a minimally dependent order. |
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* algorithmic changes anyway. Several methods intrinsically |
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* sprawl because they must accumulate sets of consistent reads of |
425 |
> |
* volatiles held in local variables. Methods signalWork() and |
426 |
> |
* scan() are the main bottlenecks, so are especially heavily |
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> |
* micro-optimized/mangled. There are lots of inline assignments |
428 |
> |
* (of form "while ((local = field) != 0)") which are usually the |
429 |
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* simplest way to ensure the required read orderings (which are |
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* sometimes critical). This leads to a "C"-like style of listing |
431 |
> |
* declarations of these locals at the heads of methods or blocks. |
432 |
> |
* There are several occurrences of the unusual "do {} while |
433 |
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* (!cas...)" which is the simplest way to force an update of a |
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> |
* CAS'ed variable. There are also other coding oddities that help |
435 |
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* some methods perform reasonably even when interpreted (not |
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* compiled). |
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* |
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* The order of declarations in this file is: |
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* (1) Static utility functions |
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* (2) Nested (static) classes |
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* (3) Static fields |
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* (4) Fields, along with constants used when unpacking some of them |
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* (5) Internal control methods |
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* (6) Callbacks and other support for ForkJoinTask methods |
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* (7) Exported methods |
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* (8) Static block initializing statics in minimally dependent order |
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*/ |
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|
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// Static utilities |
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|
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/** |
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* Computes an initial hash code (also serving as a non-zero |
453 |
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* random seed) for a thread id. This method is expected to |
454 |
> |
* provide higher-quality hash codes than using method hashCode(). |
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> |
*/ |
456 |
> |
static final int hashId(long id) { |
457 |
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int h = (int)id ^ (int)(id >>> 32); // Use MurmurHash of thread id |
458 |
> |
h ^= h >>> 16; h *= 0x85ebca6b; |
459 |
> |
h ^= h >>> 13; h *= 0xc2b2ae35; |
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> |
h ^= h >>> 16; |
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> |
return (h == 0) ? 1 : h; // ensure nonzero |
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> |
} |
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> |
|
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/** |
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* If there is a security manager, makes sure caller has |
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* permission to modify threads. |
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*/ |
468 |
+ |
private static void checkPermission() { |
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+ |
SecurityManager security = System.getSecurityManager(); |
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+ |
if (security != null) |
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+ |
security.checkPermission(modifyThreadPermission); |
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} |
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+ |
|
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// Nested classes |
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|
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/** |
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* Factory for creating new {@link ForkJoinWorkerThread}s. |
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} |
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|
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/** |
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* Creates a new ForkJoinWorkerThread. This factory is used unless |
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* overridden in ForkJoinPool constructors. |
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*/ |
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public static final ForkJoinWorkerThreadFactory |
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defaultForkJoinWorkerThreadFactory; |
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|
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/** |
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* Permission required for callers of methods that may start or |
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* kill threads. |
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*/ |
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private static final RuntimePermission modifyThreadPermission; |
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|
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/** |
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* If there is a security manager, makes sure caller has |
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* permission to modify threads. |
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*/ |
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private static void checkPermission() { |
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SecurityManager security = System.getSecurityManager(); |
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if (security != null) |
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security.checkPermission(modifyThreadPermission); |
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* A simple non-reentrant lock used for exclusion when managing |
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* queues and workers. We use a custom lock so that we can readily |
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* probe lock state in constructions that check among alternative |
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* actions. The lock is normally only very briefly held, and |
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* sometimes treated as a spinlock, but other usages block to |
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> |
* reduce overall contention in those cases where locked code |
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* bodies perform allocation/resizing. |
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*/ |
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static final class Mutex extends AbstractQueuedSynchronizer { |
513 |
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public final boolean tryAcquire(int ignore) { |
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return compareAndSetState(0, 1); |
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} |
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public final boolean tryRelease(int ignore) { |
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setState(0); |
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return true; |
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} |
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> |
public final void lock() { acquire(0); } |
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public final void unlock() { release(0); } |
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public final boolean isHeldExclusively() { return getState() == 1; } |
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> |
public final Condition newCondition() { return new ConditionObject(); } |
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} |
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|
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/** |
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* Generator for assigning sequence numbers as pool names. |
528 |
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*/ |
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< |
private static final AtomicInteger poolNumberGenerator; |
530 |
< |
|
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< |
/** |
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* Bits and masks for control variables |
507 |
< |
* |
508 |
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* Field ctl is a long packed with: |
509 |
< |
* AC: Number of active running workers minus target parallelism (16 bits) |
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< |
* TC: Number of total workers minus target parallelism (16 bits) |
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* ST: true if pool is terminating (1 bit) |
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< |
* EC: the wait count of top waiting thread (15 bits) |
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< |
* ID: ~(poolIndex >>> 1) of top of Treiber stack of waiters (16 bits) |
514 |
< |
* |
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< |
* When convenient, we can extract the upper 32 bits of counts and |
516 |
< |
* the lower 32 bits of queue state, u = (int)(ctl >>> 32) and e = |
517 |
< |
* (int)ctl. The ec field is never accessed alone, but always |
518 |
< |
* together with id and st. The offsets of counts by the target |
519 |
< |
* parallelism and the positionings of fields makes it possible to |
520 |
< |
* perform the most common checks via sign tests of fields: When |
521 |
< |
* ac is negative, there are not enough active workers, when tc is |
522 |
< |
* negative, there are not enough total workers, when id is |
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< |
* negative, there is at least one waiting worker, and when e is |
524 |
< |
* negative, the pool is terminating. To deal with these possibly |
525 |
< |
* negative fields, we use casts in and out of "short" and/or |
526 |
< |
* signed shifts to maintain signedness. |
527 |
< |
* |
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< |
* When a thread is queued (inactivated), its eventCount field is |
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< |
* negative, which is the only way to tell if a worker is |
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< |
* prevented from executing tasks, even though it must continue to |
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< |
* scan for them to avoid queuing races. |
532 |
< |
* |
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< |
* Field runState is an int packed with: |
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< |
* SHUTDOWN: true if shutdown is enabled (1 bit) |
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< |
* SEQ: a sequence number updated upon (de)registering workers (15 bits) |
536 |
< |
* MASK: mask (power of 2 - 1) covering all registered poolIndexes (16 bits) |
537 |
< |
* |
538 |
< |
* The combination of mask and sequence number enables simple |
539 |
< |
* consistency checks: Staleness of read-only operations on the |
540 |
< |
* workers and queues arrays can be checked by comparing runState |
541 |
< |
* before vs after the reads. The low 16 bits (i.e, anding with |
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< |
* SMASK) hold (the smallest power of two covering all worker |
543 |
< |
* indices, minus one. The mask for queues (vs workers) is twice |
544 |
< |
* this value plus 1. |
545 |
< |
*/ |
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< |
|
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< |
// bit positions/shifts for fields |
548 |
< |
private static final int AC_SHIFT = 48; |
549 |
< |
private static final int TC_SHIFT = 32; |
550 |
< |
private static final int ST_SHIFT = 31; |
551 |
< |
private static final int EC_SHIFT = 16; |
552 |
< |
|
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< |
// bounds |
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< |
private static final int MAX_ID = 0x7fff; // max poolIndex |
555 |
< |
private static final int SMASK = 0xffff; // mask short bits |
556 |
< |
private static final int SHORT_SIGN = 1 << 15; |
557 |
< |
private static final int INT_SIGN = 1 << 31; |
558 |
< |
|
559 |
< |
// masks |
560 |
< |
private static final long STOP_BIT = 0x0001L << ST_SHIFT; |
561 |
< |
private static final long AC_MASK = ((long)SMASK) << AC_SHIFT; |
562 |
< |
private static final long TC_MASK = ((long)SMASK) << TC_SHIFT; |
563 |
< |
|
564 |
< |
// units for incrementing and decrementing |
565 |
< |
private static final long TC_UNIT = 1L << TC_SHIFT; |
566 |
< |
private static final long AC_UNIT = 1L << AC_SHIFT; |
567 |
< |
|
568 |
< |
// masks and units for dealing with u = (int)(ctl >>> 32) |
569 |
< |
private static final int UAC_SHIFT = AC_SHIFT - 32; |
570 |
< |
private static final int UTC_SHIFT = TC_SHIFT - 32; |
571 |
< |
private static final int UAC_MASK = SMASK << UAC_SHIFT; |
572 |
< |
private static final int UTC_MASK = SMASK << UTC_SHIFT; |
573 |
< |
private static final int UAC_UNIT = 1 << UAC_SHIFT; |
574 |
< |
private static final int UTC_UNIT = 1 << UTC_SHIFT; |
575 |
< |
|
576 |
< |
// masks and units for dealing with e = (int)ctl |
577 |
< |
private static final int E_MASK = 0x7fffffff; // no STOP_BIT |
578 |
< |
private static final int E_SEQ = 1 << EC_SHIFT; |
579 |
< |
|
580 |
< |
// runState bits |
581 |
< |
private static final int SHUTDOWN = 1 << 31; |
582 |
< |
private static final int RS_SEQ = 1 << 16; |
583 |
< |
private static final int RS_SEQ_MASK = 0x7fff0000; |
584 |
< |
|
585 |
< |
// access mode for WorkQueue |
586 |
< |
static final int LIFO_QUEUE = 0; |
587 |
< |
static final int FIFO_QUEUE = 1; |
588 |
< |
static final int SHARED_QUEUE = -1; |
589 |
< |
|
590 |
< |
/** |
591 |
< |
* The wakeup interval (in nanoseconds) for a worker waiting for a |
592 |
< |
* task when the pool is quiescent to instead try to shrink the |
593 |
< |
* number of workers. The exact value does not matter too |
594 |
< |
* much. It must be short enough to release resources during |
595 |
< |
* sustained periods of idleness, but not so short that threads |
596 |
< |
* are continually re-created. |
597 |
< |
*/ |
598 |
< |
private static final long SHRINK_RATE = |
599 |
< |
4L * 1000L * 1000L * 1000L; // 4 seconds |
600 |
< |
|
601 |
< |
/** |
602 |
< |
* The timeout value for attempted shrinkage, includes |
603 |
< |
* some slop to cope with system timer imprecision. |
604 |
< |
*/ |
605 |
< |
private static final long SHRINK_TIMEOUT = SHRINK_RATE - (SHRINK_RATE / 10); |
606 |
< |
|
607 |
< |
/** |
608 |
< |
* The maximum stolen->joining link depth allowed in tryHelpStealer. |
609 |
< |
* Depths for legitimate chains are unbounded, but we use a fixed |
610 |
< |
* constant to avoid (otherwise unchecked) cycles and to bound |
611 |
< |
* staleness of traversal parameters at the expense of sometimes |
612 |
< |
* blocking when we could be helping. |
613 |
< |
*/ |
614 |
< |
private static final int MAX_HELP_DEPTH = 16; |
615 |
< |
|
616 |
< |
/* |
617 |
< |
* Field layout order in this class tends to matter more than one |
618 |
< |
* would like. Runtime layout order is only loosely related to |
619 |
< |
* declaration order and may differ across JVMs, but the following |
620 |
< |
* empirically works OK on current JVMs. |
527 |
> |
* Class for artificial tasks that are used to replace the target |
528 |
> |
* of local joins if they are removed from an interior queue slot |
529 |
> |
* in WorkQueue.tryRemoveAndExec. We don't need the proxy to |
530 |
> |
* actually do anything beyond having a unique identity. |
531 |
|
*/ |
532 |
< |
|
533 |
< |
volatile long ctl; // main pool control |
534 |
< |
final int parallelism; // parallelism level |
535 |
< |
final int localMode; // per-worker scheduling mode |
536 |
< |
int nextPoolIndex; // hint used in registerWorker |
537 |
< |
volatile int runState; // shutdown status, seq, and mask |
628 |
< |
WorkQueue[] workQueues; // main registry |
629 |
< |
final ReentrantLock lock; // for registration |
630 |
< |
final Condition termination; // for awaitTermination |
631 |
< |
final ForkJoinWorkerThreadFactory factory; // factory for new workers |
632 |
< |
final Thread.UncaughtExceptionHandler ueh; // per-worker UEH |
633 |
< |
final AtomicLong stealCount; // collect counts when terminated |
634 |
< |
final AtomicInteger nextWorkerNumber; // to create worker name string |
635 |
< |
final String workerNamePrefix; // Prefix for assigning worker names |
532 |
> |
static final class EmptyTask extends ForkJoinTask<Void> { |
533 |
> |
EmptyTask() { status = ForkJoinTask.NORMAL; } // force done |
534 |
> |
public final Void getRawResult() { return null; } |
535 |
> |
public final void setRawResult(Void x) {} |
536 |
> |
public final boolean exec() { return true; } |
537 |
> |
} |
538 |
|
|
539 |
|
/** |
540 |
|
* Queues supporting work-stealing as well as external task |
585 |
|
* avoiding really bad worst-case access. (Until better JVM |
586 |
|
* support is in place, this padding is dependent on transient |
587 |
|
* properties of JVM field layout rules.) We also take care in |
588 |
< |
* allocating and sizing and resizing the array. Non-shared queue |
588 |
> |
* allocating, sizing and resizing the array. Non-shared queue |
589 |
|
* arrays are initialized (via method growArray) by workers before |
590 |
|
* use. Others are allocated on first use. |
591 |
|
*/ |
634 |
|
} |
635 |
|
|
636 |
|
/** |
637 |
< |
* Returns number of tasks in the queue |
637 |
> |
* Returns number of tasks in the queue. |
638 |
|
*/ |
639 |
|
final int queueSize() { |
640 |
|
int n = base - top; // non-owner callers must read base first |
645 |
|
* Pushes a task. Call only by owner in unshared queues. |
646 |
|
* |
647 |
|
* @param task the task. Caller must ensure non-null. |
648 |
< |
* @param p, if non-null, pool to signal if necessary |
649 |
< |
* @throw RejectedExecutionException if array cannot |
748 |
< |
* be resized |
648 |
> |
* @param p if non-null, pool to signal if necessary |
649 |
> |
* @throw RejectedExecutionException if array cannot be resized |
650 |
|
*/ |
651 |
|
final void push(ForkJoinTask<?> task, ForkJoinPool p) { |
652 |
|
ForkJoinTask<?>[] a; |
674 |
|
boolean submitted = false; |
675 |
|
if (runState == 0 && U.compareAndSwapInt(this, RUNSTATE, 0, 1)) { |
676 |
|
ForkJoinTask<?>[] a = array; |
677 |
< |
int s = top, n = s - base; |
677 |
> |
int s = top; |
678 |
|
try { |
679 |
< |
if ((a != null && n < a.length - 1) || |
679 |
> |
if ((a != null && a.length > s + 1 - base) || |
680 |
|
(a = growArray(false)) != null) { // must presize |
681 |
|
int j = (((a.length - 1) & s) << ASHIFT) + ABASE; |
682 |
|
U.putObject(a, (long)j, task); // don't need "ordered" |
694 |
|
* Takes next task, if one exists, in FIFO order. |
695 |
|
*/ |
696 |
|
final ForkJoinTask<?> poll() { |
697 |
< |
ForkJoinTask<?>[] a; int b, i; |
698 |
< |
while ((b = base) - top < 0 && (a = array) != null && |
699 |
< |
(i = (a.length - 1) & b) >= 0) { |
700 |
< |
int j = (i << ASHIFT) + ABASE; |
701 |
< |
ForkJoinTask<?> t = (ForkJoinTask<?>)U.getObjectVolatile(a, j); |
801 |
< |
if (t != null && base == b && |
697 |
> |
ForkJoinTask<?>[] a; int b; ForkJoinTask<?> t; |
698 |
> |
while ((b = base) - top < 0 && (a = array) != null) { |
699 |
> |
int j = (((a.length - 1) & b) << ASHIFT) + ABASE; |
700 |
> |
if ((t = (ForkJoinTask<?>)U.getObjectVolatile(a, j)) != null && |
701 |
> |
base == b && |
702 |
|
U.compareAndSwapObject(a, j, t, null)) { |
703 |
|
base = b + 1; |
704 |
|
return t; |
708 |
|
} |
709 |
|
|
710 |
|
/** |
711 |
< |
* Takes next task, if one exists, in LIFO order. |
712 |
< |
* Call only by owner in unshared queues. |
711 |
> |
* Takes next task, if one exists, in LIFO order. Call only |
712 |
> |
* by owner in unshared queues. (We do not have a shared |
713 |
> |
* version of this method because it is never needed.) |
714 |
|
*/ |
715 |
|
final ForkJoinTask<?> pop() { |
716 |
|
ForkJoinTask<?> t; int m; |
752 |
|
* Returns task at index b if b is current base of queue. |
753 |
|
*/ |
754 |
|
final ForkJoinTask<?> pollAt(int b) { |
755 |
< |
ForkJoinTask<?>[] a; int i; |
756 |
< |
ForkJoinTask<?> task = null; |
757 |
< |
if ((a = array) != null && (i = ((a.length - 1) & b)) >= 0) { |
758 |
< |
int j = (i << ASHIFT) + ABASE; |
759 |
< |
ForkJoinTask<?> t = (ForkJoinTask<?>)U.getObjectVolatile(a, j); |
859 |
< |
if (t != null && base == b && |
755 |
> |
ForkJoinTask<?> t; ForkJoinTask<?>[] a; |
756 |
> |
if ((a = array) != null) { |
757 |
> |
int j = (((a.length - 1) & b) << ASHIFT) + ABASE; |
758 |
> |
if ((t = (ForkJoinTask<?>)U.getObjectVolatile(a, j)) != null && |
759 |
> |
base == b && |
760 |
|
U.compareAndSwapObject(a, j, t, null)) { |
761 |
|
base = b + 1; |
762 |
< |
task = t; |
762 |
> |
return t; |
763 |
|
} |
764 |
|
} |
765 |
< |
return task; |
765 |
> |
return null; |
766 |
|
} |
767 |
|
|
768 |
|
/** |
783 |
|
* Polls the given task only if it is at the current base. |
784 |
|
*/ |
785 |
|
final boolean pollFor(ForkJoinTask<?> task) { |
786 |
< |
ForkJoinTask<?>[] a; int b, i; |
787 |
< |
if ((b = base) - top < 0 && (a = array) != null && |
788 |
< |
(i = (a.length - 1) & b) >= 0) { |
889 |
< |
int j = (i << ASHIFT) + ABASE; |
786 |
> |
ForkJoinTask<?>[] a; int b; |
787 |
> |
if ((b = base) - top < 0 && (a = array) != null) { |
788 |
> |
int j = (((a.length - 1) & b) << ASHIFT) + ABASE; |
789 |
|
if (U.getObjectVolatile(a, j) == task && base == b && |
790 |
|
U.compareAndSwapObject(a, j, task, null)) { |
791 |
|
base = b + 1; |
879 |
|
} |
880 |
|
|
881 |
|
/** |
882 |
< |
* Removes and cancels all known tasks, ignoring any exceptions |
882 |
> |
* Removes and cancels all known tasks, ignoring any exceptions. |
883 |
|
*/ |
884 |
|
final void cancelAll() { |
885 |
|
ForkJoinTask.cancelIgnoringExceptions(currentJoin); |
888 |
|
ForkJoinTask.cancelIgnoringExceptions(t); |
889 |
|
} |
890 |
|
|
891 |
+ |
/** |
892 |
+ |
* Computes next value for random probes. Scans don't require |
893 |
+ |
* a very high quality generator, but also not a crummy one. |
894 |
+ |
* Marsaglia xor-shift is cheap and works well enough. Note: |
895 |
+ |
* This is manually inlined in several usages in ForkJoinPool |
896 |
+ |
* to avoid writes inside busy scan loops. |
897 |
+ |
*/ |
898 |
+ |
final int nextSeed() { |
899 |
+ |
int r = seed; |
900 |
+ |
r ^= r << 13; |
901 |
+ |
r ^= r >>> 17; |
902 |
+ |
return seed = r ^= r << 5; |
903 |
+ |
} |
904 |
+ |
|
905 |
|
// Execution methods |
906 |
|
|
907 |
|
/** |
936 |
|
} |
937 |
|
|
938 |
|
/** |
939 |
< |
* Executes a non-top-level (stolen) task |
939 |
> |
* Executes a non-top-level (stolen) task. |
940 |
|
*/ |
941 |
|
final void runSubtask(ForkJoinTask<?> t) { |
942 |
|
if (t != null) { |
948 |
|
} |
949 |
|
|
950 |
|
/** |
951 |
< |
* Computes next value for random probes. Scans don't require |
1039 |
< |
* a very high quality generator, but also not a crummy one. |
1040 |
< |
* Marsaglia xor-shift is cheap and works well enough. Note: |
1041 |
< |
* This is manually inlined in several usages in ForkJoinPool |
1042 |
< |
* to avoid writes inside busy scan loops. |
951 |
> |
* Returns true if owned and not known to be blocked. |
952 |
|
*/ |
953 |
< |
final int nextSeed() { |
954 |
< |
int r = seed; |
955 |
< |
r ^= r << 13; |
956 |
< |
r ^= r >>> 17; |
957 |
< |
r ^= r << 5; |
958 |
< |
return seed = r; |
953 |
> |
final boolean isApparentlyUnblocked() { |
954 |
> |
Thread wt; Thread.State s; |
955 |
> |
return (eventCount >= 0 && |
956 |
> |
(wt = owner) != null && |
957 |
> |
(s = wt.getState()) != Thread.State.BLOCKED && |
958 |
> |
s != Thread.State.WAITING && |
959 |
> |
s != Thread.State.TIMED_WAITING); |
960 |
> |
} |
961 |
> |
|
962 |
> |
/** |
963 |
> |
* If this owned and is not already interrupted, try to |
964 |
> |
* interrupt and/or unpark, ignoring exceptions. |
965 |
> |
*/ |
966 |
> |
final void interruptOwner() { |
967 |
> |
Thread wt, p; |
968 |
> |
if ((wt = owner) != null && !wt.isInterrupted()) { |
969 |
> |
try { |
970 |
> |
wt.interrupt(); |
971 |
> |
} catch (SecurityException ignore) { |
972 |
> |
} |
973 |
> |
} |
974 |
> |
if ((p = parker) != null) |
975 |
> |
U.unpark(p); |
976 |
|
} |
977 |
|
|
978 |
|
// Unsafe mechanics |
1000 |
|
} |
1001 |
|
|
1002 |
|
/** |
1003 |
< |
* Class for artificial tasks that are used to replace the target |
1004 |
< |
* of local joins if they are removed from an interior queue slot |
1005 |
< |
* in WorkQueue.tryRemoveAndExec. We don't need the proxy to |
1006 |
< |
* actually do anything beyond having a unique identity. |
1007 |
< |
*/ |
1082 |
< |
static final class EmptyTask extends ForkJoinTask<Void> { |
1083 |
< |
EmptyTask() { status = ForkJoinTask.NORMAL; } // force done |
1084 |
< |
public Void getRawResult() { return null; } |
1085 |
< |
public void setRawResult(Void x) {} |
1086 |
< |
public boolean exec() { return true; } |
1087 |
< |
} |
1088 |
< |
|
1089 |
< |
/** |
1090 |
< |
<<<<<<< ForkJoinPool.java |
1091 |
< |
* Per-thread records for (typically non-FJ) threads that submit |
1092 |
< |
* to pools. Cureently holds only psuedo-random seed / index that |
1093 |
< |
* is used to chose submission queues in method doSubmit. In the |
1094 |
< |
* future, this may incorporate a means to implement different |
1095 |
< |
* task rejection and resubmission policies. |
1003 |
> |
* Per-thread records for threads that submit to pools. Currently |
1004 |
> |
* holds only pseudo-random seed / index that is used to choose |
1005 |
> |
* submission queues in method doSubmit. In the future, this may |
1006 |
> |
* also incorporate a means to implement different task rejection |
1007 |
> |
* and resubmission policies. |
1008 |
|
*/ |
1009 |
|
static final class Submitter { |
1010 |
< |
int seed; // seed for random submission queue selection |
1011 |
< |
|
1100 |
< |
// Heuristic padding to ameliorate unfortunate memory placements |
1101 |
< |
int p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, pa, pb, pc, pd, pe; |
1102 |
< |
|
1103 |
< |
Submitter() { |
1104 |
< |
// Use identityHashCode, forced negative, for seed |
1105 |
< |
seed = System.identityHashCode(Thread.currentThread()) | (1 << 31); |
1106 |
< |
} |
1107 |
< |
|
1108 |
< |
/** |
1109 |
< |
* Computes next value for random probes. Like method |
1110 |
< |
* WorkQueue.nextSeed, this is manually inlined in several |
1111 |
< |
* usages to avoid writes inside busy loops. |
1112 |
< |
*/ |
1113 |
< |
final int nextSeed() { |
1114 |
< |
int r = seed; |
1115 |
< |
r ^= r << 13; |
1116 |
< |
r ^= r >>> 17; |
1117 |
< |
return seed = r ^= r << 5; |
1118 |
< |
} |
1010 |
> |
int seed; |
1011 |
> |
Submitter() { seed = hashId(Thread.currentThread().getId()); } |
1012 |
|
} |
1013 |
|
|
1014 |
|
/** ThreadLocal class for Submitters */ |
1016 |
|
public Submitter initialValue() { return new Submitter(); } |
1017 |
|
} |
1018 |
|
|
1019 |
+ |
// static fields (initialized in static initializer below) |
1020 |
+ |
|
1021 |
+ |
/** |
1022 |
+ |
* Creates a new ForkJoinWorkerThread. This factory is used unless |
1023 |
+ |
* overridden in ForkJoinPool constructors. |
1024 |
+ |
*/ |
1025 |
+ |
public static final ForkJoinWorkerThreadFactory |
1026 |
+ |
defaultForkJoinWorkerThreadFactory; |
1027 |
+ |
|
1028 |
+ |
/** |
1029 |
+ |
* Generator for assigning sequence numbers as pool names. |
1030 |
+ |
*/ |
1031 |
+ |
private static final AtomicInteger poolNumberGenerator; |
1032 |
+ |
|
1033 |
+ |
/** |
1034 |
+ |
* Permission required for callers of methods that may start or |
1035 |
+ |
* kill threads. |
1036 |
+ |
*/ |
1037 |
+ |
private static final RuntimePermission modifyThreadPermission; |
1038 |
+ |
|
1039 |
|
/** |
1040 |
|
* Per-thread submission bookeeping. Shared across all pools |
1041 |
|
* to reduce ThreadLocal pollution and because random motion |
1042 |
|
* to avoid contention in one pool is likely to hold for others. |
1043 |
|
*/ |
1044 |
< |
static final ThreadSubmitter submitters = new ThreadSubmitter(); |
1044 |
> |
private static final ThreadSubmitter submitters; |
1045 |
> |
|
1046 |
> |
// static constants |
1047 |
|
|
1048 |
|
/** |
1049 |
< |
* Top-level runloop for workers |
1049 |
> |
* The wakeup interval (in nanoseconds) for a worker waiting for a |
1050 |
> |
* task when the pool is quiescent to instead try to shrink the |
1051 |
> |
* number of workers. The exact value does not matter too |
1052 |
> |
* much. It must be short enough to release resources during |
1053 |
> |
* sustained periods of idleness, but not so short that threads |
1054 |
> |
* are continually re-created. |
1055 |
|
*/ |
1056 |
< |
final void runWorker(ForkJoinWorkerThread wt) { |
1057 |
< |
// Initialize queue array and seed in this thread |
1138 |
< |
WorkQueue w = wt.workQueue; |
1139 |
< |
w.growArray(false); |
1140 |
< |
// Same initial hash as Submitters |
1141 |
< |
w.seed = System.identityHashCode(Thread.currentThread()) | (1 << 31); |
1056 |
> |
private static final long SHRINK_RATE = |
1057 |
> |
4L * 1000L * 1000L * 1000L; // 4 seconds |
1058 |
|
|
1059 |
< |
do {} while (w.runTask(scan(w))); |
1060 |
< |
} |
1059 |
> |
/** |
1060 |
> |
* The timeout value for attempted shrinkage, includes |
1061 |
> |
* some slop to cope with system timer imprecision. |
1062 |
> |
*/ |
1063 |
> |
private static final long SHRINK_TIMEOUT = SHRINK_RATE - (SHRINK_RATE / 10); |
1064 |
|
|
1065 |
< |
// Creating, registering and deregistering workers |
1065 |
> |
/** |
1066 |
> |
* The maximum stolen->joining link depth allowed in tryHelpStealer. |
1067 |
> |
* Depths for legitimate chains are unbounded, but we use a fixed |
1068 |
> |
* constant to avoid (otherwise unchecked) cycles and to bound |
1069 |
> |
* staleness of traversal parameters at the expense of sometimes |
1070 |
> |
* blocking when we could be helping. |
1071 |
> |
*/ |
1072 |
> |
private static final int MAX_HELP_DEPTH = 16; |
1073 |
> |
|
1074 |
> |
/** |
1075 |
> |
* Bits and masks for control variables |
1076 |
> |
* |
1077 |
> |
* Field ctl is a long packed with: |
1078 |
> |
* AC: Number of active running workers minus target parallelism (16 bits) |
1079 |
> |
* TC: Number of total workers minus target parallelism (16 bits) |
1080 |
> |
* ST: true if pool is terminating (1 bit) |
1081 |
> |
* EC: the wait count of top waiting thread (15 bits) |
1082 |
> |
* ID: poolIndex of top of Treiber stack of waiters (16 bits) |
1083 |
> |
* |
1084 |
> |
* When convenient, we can extract the upper 32 bits of counts and |
1085 |
> |
* the lower 32 bits of queue state, u = (int)(ctl >>> 32) and e = |
1086 |
> |
* (int)ctl. The ec field is never accessed alone, but always |
1087 |
> |
* together with id and st. The offsets of counts by the target |
1088 |
> |
* parallelism and the positionings of fields makes it possible to |
1089 |
> |
* perform the most common checks via sign tests of fields: When |
1090 |
> |
* ac is negative, there are not enough active workers, when tc is |
1091 |
> |
* negative, there are not enough total workers, and when e is |
1092 |
> |
* negative, the pool is terminating. To deal with these possibly |
1093 |
> |
* negative fields, we use casts in and out of "short" and/or |
1094 |
> |
* signed shifts to maintain signedness. |
1095 |
> |
* |
1096 |
> |
* When a thread is queued (inactivated), its eventCount field is |
1097 |
> |
* set negative, which is the only way to tell if a worker is |
1098 |
> |
* prevented from executing tasks, even though it must continue to |
1099 |
> |
* scan for them to avoid queuing races. Note however that |
1100 |
> |
* eventCount updates lag releases so usage requires care. |
1101 |
> |
* |
1102 |
> |
* Field runState is an int packed with: |
1103 |
> |
* SHUTDOWN: true if shutdown is enabled (1 bit) |
1104 |
> |
* SEQ: a sequence number updated upon (de)registering workers (15 bits) |
1105 |
> |
* MASK: mask (power of 2 - 1) covering all registered poolIndexes (16 bits) |
1106 |
> |
* |
1107 |
> |
* The combination of mask and sequence number enables simple |
1108 |
> |
* consistency checks: Staleness of read-only operations on the |
1109 |
> |
* workQueues array can be checked by comparing runState before vs |
1110 |
> |
* after the reads. The low 16 bits (i.e, anding with SMASK) hold |
1111 |
> |
* the smallest power of two covering all indices, minus |
1112 |
> |
* one. |
1113 |
> |
*/ |
1114 |
> |
|
1115 |
> |
// bit positions/shifts for fields |
1116 |
> |
private static final int AC_SHIFT = 48; |
1117 |
> |
private static final int TC_SHIFT = 32; |
1118 |
> |
private static final int ST_SHIFT = 31; |
1119 |
> |
private static final int EC_SHIFT = 16; |
1120 |
> |
|
1121 |
> |
// bounds |
1122 |
> |
private static final int POOL_MAX = 0x7fff; // max #workers - 1 |
1123 |
> |
private static final int SMASK = 0xffff; // short bits |
1124 |
> |
private static final int SQMASK = 0xfffe; // even short bits |
1125 |
> |
private static final int SHORT_SIGN = 1 << 15; |
1126 |
> |
private static final int INT_SIGN = 1 << 31; |
1127 |
> |
|
1128 |
> |
// masks |
1129 |
> |
private static final long STOP_BIT = 0x0001L << ST_SHIFT; |
1130 |
> |
private static final long AC_MASK = ((long)SMASK) << AC_SHIFT; |
1131 |
> |
private static final long TC_MASK = ((long)SMASK) << TC_SHIFT; |
1132 |
> |
|
1133 |
> |
// units for incrementing and decrementing |
1134 |
> |
private static final long TC_UNIT = 1L << TC_SHIFT; |
1135 |
> |
private static final long AC_UNIT = 1L << AC_SHIFT; |
1136 |
> |
|
1137 |
> |
// masks and units for dealing with u = (int)(ctl >>> 32) |
1138 |
> |
private static final int UAC_SHIFT = AC_SHIFT - 32; |
1139 |
> |
private static final int UTC_SHIFT = TC_SHIFT - 32; |
1140 |
> |
private static final int UAC_MASK = SMASK << UAC_SHIFT; |
1141 |
> |
private static final int UTC_MASK = SMASK << UTC_SHIFT; |
1142 |
> |
private static final int UAC_UNIT = 1 << UAC_SHIFT; |
1143 |
> |
private static final int UTC_UNIT = 1 << UTC_SHIFT; |
1144 |
> |
|
1145 |
> |
// masks and units for dealing with e = (int)ctl |
1146 |
> |
private static final int E_MASK = 0x7fffffff; // no STOP_BIT |
1147 |
> |
private static final int E_SEQ = 1 << EC_SHIFT; |
1148 |
> |
|
1149 |
> |
// runState bits |
1150 |
> |
private static final int SHUTDOWN = 1 << 31; |
1151 |
> |
private static final int RS_SEQ = 1 << 16; |
1152 |
> |
private static final int RS_SEQ_MASK = 0x7fff0000; |
1153 |
> |
|
1154 |
> |
// access mode for WorkQueue |
1155 |
> |
static final int LIFO_QUEUE = 0; |
1156 |
> |
static final int FIFO_QUEUE = 1; |
1157 |
> |
static final int SHARED_QUEUE = -1; |
1158 |
> |
|
1159 |
> |
// Instance fields |
1160 |
> |
|
1161 |
> |
/* |
1162 |
> |
* Field layout order in this class tends to matter more than one |
1163 |
> |
* would like. Runtime layout order is only loosely related to |
1164 |
> |
* declaration order and may differ across JVMs, but the following |
1165 |
> |
* empirically works OK on current JVMs. |
1166 |
> |
*/ |
1167 |
> |
|
1168 |
> |
volatile long ctl; // main pool control |
1169 |
> |
final int parallelism; // parallelism level |
1170 |
> |
final int localMode; // per-worker scheduling mode |
1171 |
> |
int growHints; // for expanding indices/ranges |
1172 |
> |
volatile int runState; // shutdown status, seq, and mask |
1173 |
> |
WorkQueue[] workQueues; // main registry |
1174 |
> |
final Mutex lock; // for registration |
1175 |
> |
final Condition termination; // for awaitTermination |
1176 |
> |
final ForkJoinWorkerThreadFactory factory; // factory for new workers |
1177 |
> |
final Thread.UncaughtExceptionHandler ueh; // per-worker UEH |
1178 |
> |
final AtomicLong stealCount; // collect counts when terminated |
1179 |
> |
final AtomicInteger nextWorkerNumber; // to create worker name string |
1180 |
> |
final String workerNamePrefix; // to create worker name string |
1181 |
> |
|
1182 |
> |
// Creating, registering, deregistering and running workers |
1183 |
|
|
1184 |
|
/** |
1185 |
|
* Tries to create and start a worker |
1186 |
|
*/ |
1187 |
|
private void addWorker() { |
1188 |
|
Throwable ex = null; |
1189 |
< |
ForkJoinWorkerThread w = null; |
1189 |
> |
ForkJoinWorkerThread wt = null; |
1190 |
|
try { |
1191 |
< |
if ((w = factory.newThread(this)) != null) { |
1192 |
< |
w.start(); |
1191 |
> |
if ((wt = factory.newThread(this)) != null) { |
1192 |
> |
wt.start(); |
1193 |
|
return; |
1194 |
|
} |
1195 |
|
} catch (Throwable e) { |
1196 |
|
ex = e; |
1197 |
|
} |
1198 |
< |
deregisterWorker(w, ex); |
1198 |
> |
deregisterWorker(wt, ex); // adjust counts etc on failure |
1199 |
|
} |
1200 |
|
|
1201 |
|
/** |
1211 |
|
|
1212 |
|
/** |
1213 |
|
* Callback from ForkJoinWorkerThread constructor to establish and |
1214 |
< |
* record its WorkQueue |
1214 |
> |
* record its WorkQueue. |
1215 |
|
* |
1216 |
|
* @param wt the worker thread |
1217 |
|
*/ |
1218 |
|
final void registerWorker(ForkJoinWorkerThread wt) { |
1219 |
|
WorkQueue w = wt.workQueue; |
1220 |
< |
ReentrantLock lock = this.lock; |
1220 |
> |
Mutex lock = this.lock; |
1221 |
|
lock.lock(); |
1222 |
|
try { |
1223 |
< |
int k = nextPoolIndex; |
1223 |
> |
int g = growHints, k = g & SMASK; |
1224 |
|
WorkQueue[] ws = workQueues; |
1225 |
|
if (ws != null) { // ignore on shutdown |
1226 |
|
int n = ws.length; |
1227 |
< |
if (k < 0 || (k & 1) == 0 || k >= n || ws[k] != null) { |
1227 |
> |
if ((k & 1) == 0 || k >= n || ws[k] != null) { |
1228 |
|
for (k = 1; k < n && ws[k] != null; k += 2) |
1229 |
|
; // workers are at odd indices |
1230 |
|
if (k >= n) // resize |
1231 |
|
workQueues = ws = Arrays.copyOf(ws, n << 1); |
1232 |
|
} |
1233 |
< |
w.poolIndex = k; |
1234 |
< |
w.eventCount = ~(k >>> 1) & SMASK; // Set up wait count |
1235 |
< |
ws[k] = w; // record worker |
1200 |
< |
nextPoolIndex = k + 2; |
1233 |
> |
w.eventCount = w.poolIndex = k; // establish before recording |
1234 |
> |
ws[k] = w; |
1235 |
> |
growHints = (g & ~SMASK) | ((k + 2) & SMASK); |
1236 |
|
int rs = runState; |
1237 |
|
int m = rs & SMASK; // recalculate runState mask |
1238 |
|
if (k > m) |
1245 |
|
} |
1246 |
|
|
1247 |
|
/** |
1248 |
< |
* Final callback from terminating worker, as well as failure to |
1249 |
< |
* construct or start a worker in addWorker. Removes record of |
1248 |
> |
* Final callback from terminating worker, as well as upon failure |
1249 |
> |
* to construct or start a worker in addWorker. Removes record of |
1250 |
|
* worker from array, and adjusts counts. If pool is shutting |
1251 |
|
* down, tries to complete termination. |
1252 |
|
* |
1259 |
|
w.runState = -1; // ensure runState is set |
1260 |
|
stealCount.getAndAdd(w.totalSteals + w.nsteals); |
1261 |
|
int idx = w.poolIndex; |
1262 |
< |
ReentrantLock lock = this.lock; |
1262 |
> |
Mutex lock = this.lock; |
1263 |
|
lock.lock(); |
1264 |
|
try { // remove record from array |
1265 |
|
WorkQueue[] ws = workQueues; |
1266 |
< |
if (ws != null && idx >= 0 && idx < ws.length && ws[idx] == w) |
1267 |
< |
ws[nextPoolIndex = idx] = null; |
1266 |
> |
if (ws != null && idx >= 0 && idx < ws.length && ws[idx] == w) { |
1267 |
> |
ws[idx] = null; |
1268 |
> |
growHints = (growHints & ~SMASK) | idx; |
1269 |
> |
} |
1270 |
|
} finally { |
1271 |
|
lock.unlock(); |
1272 |
|
} |
1278 |
|
((c - TC_UNIT) & TC_MASK) | |
1279 |
|
(c & ~(AC_MASK|TC_MASK))))); |
1280 |
|
|
1281 |
< |
if (!tryTerminate(false) && w != null) { |
1281 |
> |
if (!tryTerminate(false, false) && w != null) { |
1282 |
|
w.cancelAll(); // cancel remaining tasks |
1283 |
|
if (w.array != null) // suppress signal if never ran |
1284 |
|
signalWork(); // wake up or create replacement |
1285 |
+ |
if (ex == null) // help clean refs on way out |
1286 |
+ |
ForkJoinTask.helpExpungeStaleExceptions(); |
1287 |
|
} |
1288 |
|
|
1289 |
|
if (ex != null) // rethrow |
1291 |
|
} |
1292 |
|
|
1293 |
|
/** |
1294 |
< |
* Tries to add and register a new queue at the given index. |
1295 |
< |
* |
1296 |
< |
* @param idx the workQueues array index to register the queue |
1297 |
< |
* @return the queue, or null if could not add because could |
1298 |
< |
* not acquire lock or idx is unusable |
1299 |
< |
*/ |
1300 |
< |
private WorkQueue tryAddSharedQueue(int idx) { |
1301 |
< |
WorkQueue q = null; |
1302 |
< |
ReentrantLock lock = this.lock; |
1303 |
< |
if (idx >= 0 && (idx & 1) == 0 && !lock.isLocked()) { |
1304 |
< |
// create queue outside of lock but only if apparently free |
1305 |
< |
WorkQueue nq = new WorkQueue(null, SHARED_QUEUE); |
1306 |
< |
if (lock.tryLock()) { |
1307 |
< |
try { |
1308 |
< |
WorkQueue[] ws = workQueues; |
1309 |
< |
if (ws != null && idx < ws.length) { |
1310 |
< |
if ((q = ws[idx]) == null) { |
1311 |
< |
int rs; // update runState seq |
1312 |
< |
ws[idx] = q = nq; |
1313 |
< |
runState = (((rs = runState) & SHUTDOWN) | |
1314 |
< |
((rs + RS_SEQ) & ~SHUTDOWN)); |
1315 |
< |
} |
1294 |
> |
* Top-level runloop for workers, called by ForkJoinWorkerThread.run. |
1295 |
> |
*/ |
1296 |
> |
final void runWorker(ForkJoinWorkerThread wt) { |
1297 |
> |
// Initialize queue array and seed in this thread |
1298 |
> |
WorkQueue w = wt.workQueue; |
1299 |
> |
w.growArray(false); |
1300 |
> |
w.seed = hashId(Thread.currentThread().getId()); |
1301 |
> |
|
1302 |
> |
do {} while (w.runTask(scan(w))); |
1303 |
> |
} |
1304 |
> |
|
1305 |
> |
// Submissions |
1306 |
> |
|
1307 |
> |
/** |
1308 |
> |
* Unless shutting down, adds the given task to a submission queue |
1309 |
> |
* at submitter's current queue index (modulo submission |
1310 |
> |
* range). If no queue exists at the index, one is created unless |
1311 |
> |
* pool lock is busy. If the queue and/or lock are busy, another |
1312 |
> |
* index is randomly chosen. The mask in growHints controls the |
1313 |
> |
* effective index range of queues considered. The mask is |
1314 |
> |
* expanded, up to the current workerQueue mask, upon any detected |
1315 |
> |
* contention but otherwise remains small to avoid needlessly |
1316 |
> |
* creating queues when there is no contention. |
1317 |
> |
*/ |
1318 |
> |
private void doSubmit(ForkJoinTask<?> task) { |
1319 |
> |
if (task == null) |
1320 |
> |
throw new NullPointerException(); |
1321 |
> |
Submitter s = submitters.get(); |
1322 |
> |
for (int r = s.seed, m = growHints >>> 16;;) { |
1323 |
> |
WorkQueue[] ws; WorkQueue q; Mutex lk; |
1324 |
> |
int k = r & m & SQMASK; // use only even indices |
1325 |
> |
if (runState < 0 || (ws = workQueues) == null || ws.length <= k) |
1326 |
> |
throw new RejectedExecutionException(); // shutting down |
1327 |
> |
if ((q = ws[k]) == null && (lk = lock).tryAcquire(0)) { |
1328 |
> |
try { // try to create new queue |
1329 |
> |
if (ws == workQueues && (q = ws[k]) == null) { |
1330 |
> |
int rs; // update runState seq |
1331 |
> |
ws[k] = q = new WorkQueue(null, SHARED_QUEUE); |
1332 |
> |
runState = (((rs = runState) & SHUTDOWN) | |
1333 |
> |
((rs + RS_SEQ) & ~SHUTDOWN)); |
1334 |
|
} |
1335 |
|
} finally { |
1336 |
< |
lock.unlock(); |
1336 |
> |
lk.unlock(); |
1337 |
|
} |
1338 |
|
} |
1339 |
+ |
if (q != null) { |
1340 |
+ |
if (q.trySharedPush(task)) { |
1341 |
+ |
signalWork(); |
1342 |
+ |
return; |
1343 |
+ |
} |
1344 |
+ |
else if (m < parallelism - 1 && m < (runState & SMASK)) { |
1345 |
+ |
Mutex lock = this.lock; |
1346 |
+ |
lock.lock(); // block until lock free |
1347 |
+ |
int g = growHints; |
1348 |
+ |
if (g >>> 16 == m) // expand range |
1349 |
+ |
growHints = (((m << 1) + 1) << 16) | (g & SMASK); |
1350 |
+ |
lock.unlock(); // no need for try/finally |
1351 |
+ |
} |
1352 |
+ |
else if ((r & m) == 0) |
1353 |
+ |
Thread.yield(); // occasionally yield if busy |
1354 |
+ |
} |
1355 |
+ |
if (m == (m = growHints >>> 16)) { |
1356 |
+ |
r ^= r << 13; // update seed unless new range |
1357 |
+ |
r ^= r >>> 17; // same xorshift as WorkQueues |
1358 |
+ |
s.seed = r ^= r << 5; |
1359 |
+ |
} |
1360 |
|
} |
1283 |
– |
return q; |
1361 |
|
} |
1362 |
|
|
1363 |
|
// Maintaining ctl counts |
1364 |
|
|
1365 |
|
/** |
1366 |
< |
* Increments active count; mainly called upon return from blocking |
1366 |
> |
* Increments active count; mainly called upon return from blocking. |
1367 |
|
*/ |
1368 |
|
final void incrementActiveCount() { |
1369 |
|
long c; |
1371 |
|
} |
1372 |
|
|
1373 |
|
/** |
1374 |
< |
* Activates or creates a worker |
1374 |
> |
* Tries to activate or create a worker if too few are active. |
1375 |
|
*/ |
1376 |
|
final void signalWork() { |
1377 |
< |
/* |
1378 |
< |
* The while condition is true if: (there is are too few total |
1379 |
< |
* workers OR there is at least one waiter) AND (there are too |
1380 |
< |
* few active workers OR the pool is terminating). The value |
1381 |
< |
* of e distinguishes the remaining cases: zero (no waiters) |
1382 |
< |
* for create, negative if terminating (in which case do |
1383 |
< |
* nothing), else release a waiter. The secondary checks for |
1384 |
< |
* release (non-null array etc) can fail if the pool begins |
1385 |
< |
* terminating after the test, and don't impose any added cost |
1386 |
< |
* because JVMs must perform null and bounds checks anyway. |
1387 |
< |
*/ |
1388 |
< |
long c; int e, u; |
1389 |
< |
while ((((e = (int)(c = ctl)) | (u = (int)(c >>> 32))) & |
1390 |
< |
(INT_SIGN|SHORT_SIGN)) == (INT_SIGN|SHORT_SIGN)) { |
1314 |
< |
WorkQueue[] ws = workQueues; int i; WorkQueue w; Thread p; |
1315 |
< |
if (e == 0) { // add a new worker |
1316 |
< |
if (U.compareAndSwapLong |
1317 |
< |
(this, CTL, c, (long)(((u + UTC_UNIT) & UTC_MASK) | |
1318 |
< |
((u + UAC_UNIT) & UAC_MASK)) << 32)) { |
1319 |
< |
addWorker(); |
1320 |
< |
break; |
1377 |
> |
long c; int u; |
1378 |
> |
while ((u = (int)((c = ctl) >>> 32)) < 0) { // too few active |
1379 |
> |
WorkQueue[] ws = workQueues; int e, i; WorkQueue w; Thread p; |
1380 |
> |
if ((e = (int)c) > 0) { // at least one waiting |
1381 |
> |
if (ws != null && (i = e & SMASK) < ws.length && |
1382 |
> |
(w = ws[i]) != null && w.eventCount == (e | INT_SIGN)) { |
1383 |
> |
long nc = (((long)(w.nextWait & E_MASK)) | |
1384 |
> |
((long)(u + UAC_UNIT) << 32)); |
1385 |
> |
if (U.compareAndSwapLong(this, CTL, c, nc)) { |
1386 |
> |
w.eventCount = (e + E_SEQ) & E_MASK; |
1387 |
> |
if ((p = w.parker) != null) |
1388 |
> |
U.unpark(p); // activate and release |
1389 |
> |
break; |
1390 |
> |
} |
1391 |
|
} |
1392 |
+ |
else |
1393 |
+ |
break; |
1394 |
|
} |
1395 |
< |
else if (e > 0 && ws != null && |
1396 |
< |
(i = ((~e << 1) | 1) & SMASK) < ws.length && |
1397 |
< |
(w = ws[i]) != null && |
1398 |
< |
w.eventCount == (e | INT_SIGN)) { |
1399 |
< |
if (U.compareAndSwapLong |
1328 |
< |
(this, CTL, c, (((long)(w.nextWait & E_MASK)) | |
1329 |
< |
((long)(u + UAC_UNIT) << 32)))) { |
1330 |
< |
w.eventCount = (e + E_SEQ) & E_MASK; |
1331 |
< |
if ((p = w.parker) != null) |
1332 |
< |
U.unpark(p); // release a waiting worker |
1395 |
> |
else if (e == 0 && (u & SHORT_SIGN) != 0) { // too few total |
1396 |
> |
long nc = (long)(((u + UTC_UNIT) & UTC_MASK) | |
1397 |
> |
((u + UAC_UNIT) & UAC_MASK)) << 32; |
1398 |
> |
if (U.compareAndSwapLong(this, CTL, c, nc)) { |
1399 |
> |
addWorker(); |
1400 |
|
break; |
1401 |
|
} |
1402 |
|
} |
1413 |
|
* @return true if the caller can block, else should recheck and retry |
1414 |
|
*/ |
1415 |
|
final boolean tryCompensate() { |
1416 |
< |
WorkQueue[] ws; WorkQueue w; Thread p; |
1416 |
> |
WorkQueue w; Thread p; |
1417 |
|
int pc = parallelism, e, u, ac, tc, i; |
1418 |
|
long c = ctl; |
1419 |
< |
|
1419 |
> |
WorkQueue[] ws = workQueues; |
1420 |
|
if ((e = (int)c) >= 0) { |
1421 |
|
if ((ac = ((u = (int)(c >>> 32)) >> UAC_SHIFT)) <= 0 && |
1422 |
< |
e != 0 && (ws = workQueues) != null && |
1356 |
< |
(i = ((~e << 1) | 1) & SMASK) < ws.length && |
1422 |
> |
e != 0 && ws != null && (i = e & SMASK) < ws.length && |
1423 |
|
(w = ws[i]) != null) { |
1424 |
+ |
long nc = (long)(w.nextWait & E_MASK) | (c & (AC_MASK|TC_MASK)); |
1425 |
|
if (w.eventCount == (e | INT_SIGN) && |
1426 |
< |
U.compareAndSwapLong |
1360 |
< |
(this, CTL, c, ((long)(w.nextWait & E_MASK) | |
1361 |
< |
(c & (AC_MASK|TC_MASK))))) { |
1426 |
> |
U.compareAndSwapLong(this, CTL, c, nc)) { |
1427 |
|
w.eventCount = (e + E_SEQ) & E_MASK; |
1428 |
|
if ((p = w.parker) != null) |
1429 |
|
U.unpark(p); |
1435 |
|
if (U.compareAndSwapLong(this, CTL, c, nc)) |
1436 |
|
return true; // no compensation needed |
1437 |
|
} |
1438 |
< |
else if (tc + pc < MAX_ID) { |
1438 |
> |
else if (tc + pc < POOL_MAX) { |
1439 |
|
long nc = ((c + TC_UNIT) & TC_MASK) | (c & ~TC_MASK); |
1440 |
|
if (U.compareAndSwapLong(this, CTL, c, nc)) { |
1441 |
|
addWorker(); |
1446 |
|
return false; |
1447 |
|
} |
1448 |
|
|
1384 |
– |
// Submissions |
1385 |
– |
|
1386 |
– |
/** |
1387 |
– |
* Unless shutting down, adds the given task to a submission queue |
1388 |
– |
* at submitter's current queue index. If no queue exists at the |
1389 |
– |
* index, one is created unless pool lock is busy. If the queue |
1390 |
– |
* and/or lock are busy, another index is randomly chosen. |
1391 |
– |
*/ |
1392 |
– |
private void doSubmit(ForkJoinTask<?> task) { |
1393 |
– |
if (task == null) |
1394 |
– |
throw new NullPointerException(); |
1395 |
– |
Submitter s = submitters.get(); |
1396 |
– |
for (int r = s.seed;;) { |
1397 |
– |
WorkQueue q; int k; |
1398 |
– |
int rs = runState, m = rs & SMASK; |
1399 |
– |
WorkQueue[] ws = workQueues; |
1400 |
– |
if (rs < 0 || ws == null) // shutting down |
1401 |
– |
throw new RejectedExecutionException(); |
1402 |
– |
if (ws.length > m && // k must be at index |
1403 |
– |
((q = ws[k = (r << 1) & m]) != null || |
1404 |
– |
(q = tryAddSharedQueue(k)) != null) && |
1405 |
– |
q.trySharedPush(task)) { |
1406 |
– |
signalWork(); |
1407 |
– |
return; |
1408 |
– |
} |
1409 |
– |
r ^= r << 13; // xorshift seed to new position |
1410 |
– |
r ^= r >>> 17; |
1411 |
– |
if (((s.seed = r ^= r << 5) & m) == 0) |
1412 |
– |
Thread.yield(); // occasionally yield if busy |
1413 |
– |
} |
1414 |
– |
} |
1415 |
– |
|
1416 |
– |
|
1449 |
|
// Scanning for tasks |
1450 |
|
|
1451 |
|
/** |
1457 |
|
* re-invocation. |
1458 |
|
* |
1459 |
|
* The scan searches for tasks across queues, randomly selecting |
1460 |
< |
* the first #queues probes, favoring steals 2:1 over submissions |
1460 |
> |
* the first #queues probes, favoring steals over submissions |
1461 |
|
* (by exploiting even/odd indexing), and then performing a |
1462 |
|
* circular sweep of all queues. The scan terminates upon either |
1463 |
|
* finding a non-empty queue, or completing a full sweep. If the |
1466 |
|
* following actions, after which the caller will retry calling |
1467 |
|
* this method unless terminated. |
1468 |
|
* |
1469 |
+ |
* * If pool is terminating, terminate the worker. |
1470 |
+ |
* |
1471 |
|
* * If not a complete sweep, try to release a waiting worker. If |
1472 |
|
* the scan terminated because the worker is inactivated, then the |
1473 |
|
* released worker will often be the calling worker, and it can |
1475 |
|
* another worker, but with same net effect. Releasing in other |
1476 |
|
* cases as well ensures that we have enough workers running. |
1477 |
|
* |
1478 |
< |
* * If the caller has run a task since the the last empty scan, |
1478 |
> |
* * If the caller has run a task since the last empty scan, |
1479 |
|
* return (to allow rescan) if other workers are not also yet |
1480 |
|
* enqueued. Field WorkQueue.rescans counts down on each scan to |
1481 |
< |
* ensure eventual inactivation, and occasional calls to |
1448 |
< |
* Thread.yield to help avoid interference with more useful |
1449 |
< |
* activities on the system. |
1450 |
< |
* |
1451 |
< |
* * If pool is terminating, terminate the worker |
1481 |
> |
* ensure eventual inactivation and blocking. |
1482 |
|
* |
1483 |
|
* * If not already enqueued, try to inactivate and enqueue the |
1484 |
|
* worker on wait queue. |
1492 |
|
* @return a task or null of none found |
1493 |
|
*/ |
1494 |
|
private final ForkJoinTask<?> scan(WorkQueue w) { |
1495 |
< |
boolean swept = false; // true after full empty scan |
1496 |
< |
WorkQueue[] ws; // volatile read order matters |
1497 |
< |
int r = w.seed, ec = w.eventCount; // ec is negative if inactive |
1495 |
> |
boolean swept = false; // true after full empty scan |
1496 |
> |
WorkQueue[] ws; // volatile read order matters |
1497 |
> |
int r = w.seed, ec = w.eventCount; // ec is negative if inactive |
1498 |
|
int rs = runState, m = rs & SMASK; |
1499 |
< |
if ((ws = workQueues) != null && ws.length > m) { |
1500 |
< |
ForkJoinTask<?> task = null; |
1471 |
< |
for (int k = 0, j = -2 - m; ; ++j) { |
1499 |
> |
if ((ws = workQueues) != null && ws.length > m) { // consistency check |
1500 |
> |
for (int k = 0, j = -1 - m; ; ++j) { |
1501 |
|
WorkQueue q; int b; |
1502 |
< |
if (j < 0) { // random probes while j negative |
1502 |
> |
if (j < 0) { // random probes while j negative |
1503 |
|
r ^= r << 13; r ^= r >>> 17; k = (r ^= r << 5) | (j & 1); |
1504 |
< |
} // worker (not submit) for odd j |
1505 |
< |
else // cyclic scan when j >= 0 |
1506 |
< |
k += (m >>> 1) | 1; // step by half to reduce bias |
1478 |
< |
|
1504 |
> |
} // worker (not submit) for odd j |
1505 |
> |
else // cyclic scan when j >= 0 |
1506 |
> |
k += 7; // step 7 reduces array packing bias |
1507 |
|
if ((q = ws[k & m]) != null && (b = q.base) - q.top < 0) { |
1508 |
< |
if (ec >= 0) |
1509 |
< |
task = q.pollAt(b); // steal |
1508 |
> |
ForkJoinTask<?> t = (ec >= 0) ? q.pollAt(b) : null; |
1509 |
> |
w.seed = r; // save seed for next scan |
1510 |
> |
if (t != null) |
1511 |
> |
return t; |
1512 |
|
break; |
1513 |
|
} |
1514 |
< |
else if (j > m) { |
1515 |
< |
if (rs == runState) // staleness check |
1514 |
> |
else if (j - m > m) { |
1515 |
> |
if (rs == runState) // staleness check |
1516 |
|
swept = true; |
1517 |
|
break; |
1518 |
|
} |
1519 |
|
} |
1520 |
< |
w.seed = r; // save seed for next scan |
1521 |
< |
if (task != null) |
1522 |
< |
return task; |
1523 |
< |
} |
1524 |
< |
|
1525 |
< |
// Decode ctl on empty scan |
1526 |
< |
long c = ctl; int e = (int)c, a = (int)(c >> AC_SHIFT), nr, ns; |
1527 |
< |
if (!swept) { // try to release a waiter |
1528 |
< |
WorkQueue v; Thread p; |
1529 |
< |
if (e > 0 && a < 0 && ws != null && |
1530 |
< |
(v = ws[((~e << 1) | 1) & m]) != null && |
1531 |
< |
v.eventCount == (e | INT_SIGN) && U.compareAndSwapLong |
1532 |
< |
(this, CTL, c, ((long)(v.nextWait & E_MASK) | |
1533 |
< |
((c + AC_UNIT) & (AC_MASK|TC_MASK))))) { |
1534 |
< |
v.eventCount = (e + E_SEQ) & E_MASK; |
1535 |
< |
if ((p = v.parker) != null) |
1536 |
< |
U.unpark(p); |
1537 |
< |
} |
1538 |
< |
} |
1539 |
< |
else if ((nr = w.rescans) > 0) { // continue rescanning |
1540 |
< |
int ac = a + parallelism; |
1541 |
< |
if ((w.rescans = (ac < nr) ? ac : nr - 1) > 0 && w.seed < 0 && |
1542 |
< |
w.eventCount == ec) |
1543 |
< |
Thread.yield(); // 1 bit randomness for yield call |
1544 |
< |
} |
1545 |
< |
else if (e < 0) // pool is terminating |
1546 |
< |
w.runState = -1; |
1547 |
< |
else if (ec >= 0) { // try to enqueue |
1548 |
< |
long nc = (long)ec | ((c - AC_UNIT) & (AC_MASK|TC_MASK)); |
1549 |
< |
w.nextWait = e; |
1550 |
< |
w.eventCount = ec | INT_SIGN; // mark as inactive |
1551 |
< |
if (!U.compareAndSwapLong(this, CTL, c, nc)) |
1522 |
< |
w.eventCount = ec; // back out on CAS failure |
1523 |
< |
else if ((ns = w.nsteals) != 0) { // set rescans if ran task |
1524 |
< |
if (a <= 0) // ... unless too many active |
1520 |
> |
|
1521 |
> |
// Decode ctl on empty scan |
1522 |
> |
long c = ctl; int e = (int)c, a = (int)(c >> AC_SHIFT), nr, ns; |
1523 |
> |
if (e < 0) // pool is terminating |
1524 |
> |
w.runState = -1; |
1525 |
> |
else if (!swept) { // try to release a waiter |
1526 |
> |
WorkQueue v; Thread p; |
1527 |
> |
if (e > 0 && a < 0 && (v = ws[e & m]) != null && |
1528 |
> |
v.eventCount == (e | INT_SIGN)) { |
1529 |
> |
long nc = ((long)(v.nextWait & E_MASK) | |
1530 |
> |
((c + AC_UNIT) & (AC_MASK|TC_MASK))); |
1531 |
> |
if (U.compareAndSwapLong(this, CTL, c, nc)) { |
1532 |
> |
v.eventCount = (e + E_SEQ) & E_MASK; |
1533 |
> |
if ((p = v.parker) != null) |
1534 |
> |
U.unpark(p); |
1535 |
> |
} |
1536 |
> |
} |
1537 |
> |
} |
1538 |
> |
else if ((nr = w.rescans) > 0) { // continue rescanning |
1539 |
> |
int ac = a + parallelism; |
1540 |
> |
if (((w.rescans = (ac < nr) ? ac : nr - 1) & 3) == 0 && |
1541 |
> |
w.eventCount == ec) |
1542 |
> |
Thread.yield(); // occasionally yield |
1543 |
> |
} |
1544 |
> |
else if (ec >= 0) { // try to enqueue |
1545 |
> |
long nc = (long)ec | ((c - AC_UNIT) & (AC_MASK|TC_MASK)); |
1546 |
> |
w.nextWait = e; |
1547 |
> |
w.eventCount = ec | INT_SIGN;// mark as inactive |
1548 |
> |
if (!U.compareAndSwapLong(this, CTL, c, nc)) |
1549 |
> |
w.eventCount = ec; // unmark on CAS failure |
1550 |
> |
else if ((ns = w.nsteals) != 0) { |
1551 |
> |
w.nsteals = 0; // set rescans if ran task |
1552 |
|
w.rescans = a + parallelism; |
1553 |
< |
w.nsteals = 0; |
1554 |
< |
w.totalSteals += ns; |
1553 |
> |
w.totalSteals += ns; |
1554 |
> |
} |
1555 |
|
} |
1556 |
< |
} |
1557 |
< |
else{ // already queued |
1558 |
< |
if (parallelism == -a) |
1559 |
< |
idleAwaitWork(w); // quiescent |
1560 |
< |
if (w.eventCount == ec) { |
1561 |
< |
Thread.interrupted(); // clear status |
1562 |
< |
ForkJoinWorkerThread wt = w.owner; |
1563 |
< |
U.putObject(wt, PARKBLOCKER, this); |
1564 |
< |
w.parker = wt; // emulate LockSupport.park |
1565 |
< |
if (w.eventCount == ec) // recheck |
1566 |
< |
U.park(false, 0L); // block |
1567 |
< |
w.parker = null; |
1568 |
< |
U.putObject(wt, PARKBLOCKER, null); |
1556 |
> |
else { // already queued |
1557 |
> |
if (parallelism == -a) |
1558 |
> |
idleAwaitWork(w); // quiescent |
1559 |
> |
if (w.eventCount == ec) { |
1560 |
> |
Thread.interrupted(); // clear status |
1561 |
> |
ForkJoinWorkerThread wt = w.owner; |
1562 |
> |
U.putObject(wt, PARKBLOCKER, this); |
1563 |
> |
w.parker = wt; // emulate LockSupport.park |
1564 |
> |
if (w.eventCount == ec) // recheck |
1565 |
> |
U.park(false, 0L); // block |
1566 |
> |
w.parker = null; |
1567 |
> |
U.putObject(wt, PARKBLOCKER, null); |
1568 |
> |
} |
1569 |
|
} |
1570 |
|
} |
1571 |
|
return null; |
1573 |
|
|
1574 |
|
/** |
1575 |
|
* If inactivating worker w has caused pool to become quiescent, |
1576 |
< |
* check for pool termination, and, so long as this is not the |
1577 |
< |
* only worker, wait for event for up to SHRINK_RATE nanosecs On |
1578 |
< |
* timeout, if ctl has not changed, terminate the worker, which |
1579 |
< |
* will in turn wake up another worker to possibly repeat this |
1580 |
< |
* process. |
1576 |
> |
* checks for pool termination, and, so long as this is not the |
1577 |
> |
* only worker, waits for event for up to SHRINK_RATE nanosecs. |
1578 |
> |
* On timeout, if ctl has not changed, terminates the worker, |
1579 |
> |
* which will in turn wake up another worker to possibly repeat |
1580 |
> |
* this process. |
1581 |
|
* |
1582 |
|
* @param w the calling worker |
1583 |
|
*/ |
1584 |
|
private void idleAwaitWork(WorkQueue w) { |
1585 |
|
long c; int nw, ec; |
1586 |
< |
if (!tryTerminate(false) && |
1586 |
> |
if (!tryTerminate(false, false) && |
1587 |
|
(int)((c = ctl) >> AC_SHIFT) + parallelism == 0 && |
1588 |
|
(ec = w.eventCount) == ((int)c | INT_SIGN) && |
1589 |
|
(nw = w.nextWait) != 0) { |
1590 |
|
long nc = ((long)(nw & E_MASK) | // ctl to restore on timeout |
1591 |
|
((c + AC_UNIT) & AC_MASK) | (c & TC_MASK)); |
1565 |
– |
ForkJoinTask.helpExpungeStaleExceptions(); // help clean |
1592 |
|
ForkJoinWorkerThread wt = w.owner; |
1593 |
|
while (ctl == c) { |
1594 |
|
long startTime = System.nanoTime(); |
1603 |
|
break; |
1604 |
|
if (System.nanoTime() - startTime >= SHRINK_TIMEOUT && |
1605 |
|
U.compareAndSwapLong(this, CTL, c, nc)) { |
1580 |
– |
w.runState = -1; // shrink |
1606 |
|
w.eventCount = (ec + E_SEQ) | E_MASK; |
1607 |
+ |
w.runState = -1; // shrink |
1608 |
|
break; |
1609 |
|
} |
1610 |
|
} |
1716 |
|
return null; |
1717 |
|
if (ws.length > m) { |
1718 |
|
WorkQueue q; |
1719 |
< |
for (int n = m << 2, k = r, j = -n;;) { |
1720 |
< |
r ^= r << 13; r ^= r >>> 17; r ^= r << 5; |
1719 |
> |
for (int k = 0, j = -1 - m;; ++j) { |
1720 |
> |
if (j < 0) { |
1721 |
> |
r ^= r << 13; r ^= r >>> 17; k = r ^= r << 5; |
1722 |
> |
} |
1723 |
> |
else |
1724 |
> |
k += 7; |
1725 |
|
if ((q = ws[(k | 1) & m]) != null && q.base - q.top < 0) { |
1726 |
|
w.seed = r; |
1727 |
|
return q; |
1728 |
|
} |
1729 |
< |
else if (j > n) |
1729 |
> |
else if (j - m > m) |
1730 |
|
return null; |
1701 |
– |
else |
1702 |
– |
k = (j++ < 0) ? r : k + ((m >>> 1) | 1); |
1703 |
– |
|
1731 |
|
} |
1732 |
|
} |
1733 |
|
} |
1773 |
|
} |
1774 |
|
|
1775 |
|
/** |
1776 |
< |
* Gets and removes a local or stolen task for the given worker |
1776 |
> |
* Gets and removes a local or stolen task for the given worker. |
1777 |
|
* |
1778 |
|
* @return a task, if available |
1779 |
|
*/ |
1805 |
|
8); |
1806 |
|
} |
1807 |
|
|
1808 |
< |
// Termination |
1808 |
> |
// Termination |
1809 |
|
|
1810 |
|
/** |
1811 |
< |
* Sets SHUTDOWN bit of runState under lock |
1812 |
< |
*/ |
1813 |
< |
private void enableShutdown() { |
1814 |
< |
ReentrantLock lock = this.lock; |
1815 |
< |
if (runState >= 0) { |
1816 |
< |
lock.lock(); // don't need try/finally |
1817 |
< |
runState |= SHUTDOWN; |
1791 |
< |
lock.unlock(); |
1792 |
< |
} |
1793 |
< |
} |
1794 |
< |
|
1795 |
< |
/** |
1796 |
< |
* Possibly initiates and/or completes termination. Upon |
1797 |
< |
* termination, cancels all queued tasks and then |
1811 |
> |
* Possibly initiates and/or completes termination. The caller |
1812 |
> |
* triggering termination runs three passes through workQueues: |
1813 |
> |
* (0) Setting termination status, followed by wakeups of queued |
1814 |
> |
* workers; (1) cancelling all tasks; (2) interrupting lagging |
1815 |
> |
* threads (likely in external tasks, but possibly also blocked in |
1816 |
> |
* joins). Each pass repeats previous steps because of potential |
1817 |
> |
* lagging thread creation. |
1818 |
|
* |
1819 |
|
* @param now if true, unconditionally terminate, else only |
1820 |
|
* if no work and no active workers |
1821 |
+ |
* @param enable if true, enable shutdown when next possible |
1822 |
|
* @return true if now terminating or terminated |
1823 |
|
*/ |
1824 |
< |
private boolean tryTerminate(boolean now) { |
1824 |
> |
private boolean tryTerminate(boolean now, boolean enable) { |
1825 |
> |
Mutex lock = this.lock; |
1826 |
|
for (long c;;) { |
1827 |
|
if (((c = ctl) & STOP_BIT) != 0) { // already terminating |
1828 |
|
if ((short)(c >>> TC_SHIFT) == -parallelism) { |
1807 |
– |
ReentrantLock lock = this.lock; // signal when no workers |
1829 |
|
lock.lock(); // don't need try/finally |
1830 |
|
termination.signalAll(); // signal when 0 workers |
1831 |
|
lock.unlock(); |
1832 |
|
} |
1833 |
|
return true; |
1834 |
|
} |
1835 |
< |
if (!now) { |
1836 |
< |
if ((int)(c >> AC_SHIFT) != -parallelism || runState >= 0 || |
1835 |
> |
if (runState >= 0) { // not yet enabled |
1836 |
> |
if (!enable) |
1837 |
> |
return false; |
1838 |
> |
lock.lock(); |
1839 |
> |
runState |= SHUTDOWN; |
1840 |
> |
lock.unlock(); |
1841 |
> |
} |
1842 |
> |
if (!now) { // check if idle & no tasks |
1843 |
> |
if ((int)(c >> AC_SHIFT) != -parallelism || |
1844 |
|
hasQueuedSubmissions()) |
1845 |
|
return false; |
1846 |
|
// Check for unqueued inactive workers. One pass suffices. |
1847 |
|
WorkQueue[] ws = workQueues; WorkQueue w; |
1848 |
|
if (ws != null) { |
1849 |
< |
int n = ws.length; |
1822 |
< |
for (int i = 1; i < n; i += 2) { |
1849 |
> |
for (int i = 1; i < ws.length; i += 2) { |
1850 |
|
if ((w = ws[i]) != null && w.eventCount >= 0) |
1851 |
|
return false; |
1852 |
|
} |
1853 |
|
} |
1854 |
|
} |
1855 |
< |
if (U.compareAndSwapLong(this, CTL, c, c | STOP_BIT)) |
1856 |
< |
startTerminating(); |
1857 |
< |
} |
1858 |
< |
} |
1859 |
< |
|
1860 |
< |
/** |
1861 |
< |
* Initiates termination: Runs three passes through workQueues: |
1862 |
< |
* (0) Setting termination status, followed by wakeups of queued |
1863 |
< |
* workers; (1) cancelling all tasks; (2) interrupting lagging |
1864 |
< |
* threads (likely in external tasks, but possibly also blocked in |
1865 |
< |
* joins). Each pass repeats previous steps because of potential |
1866 |
< |
* lagging thread creation. |
1867 |
< |
*/ |
1841 |
< |
private void startTerminating() { |
1842 |
< |
for (int pass = 0; pass < 3; ++pass) { |
1843 |
< |
WorkQueue[] ws = workQueues; |
1844 |
< |
if (ws != null) { |
1845 |
< |
WorkQueue w; Thread wt; |
1846 |
< |
int n = ws.length; |
1847 |
< |
for (int j = 0; j < n; ++j) { |
1848 |
< |
if ((w = ws[j]) != null) { |
1849 |
< |
w.runState = -1; |
1850 |
< |
if (pass > 0) { |
1851 |
< |
w.cancelAll(); |
1852 |
< |
if (pass > 1 && (wt = w.owner) != null && |
1853 |
< |
!wt.isInterrupted()) { |
1854 |
< |
try { |
1855 |
< |
wt.interrupt(); |
1856 |
< |
} catch (SecurityException ignore) { |
1855 |
> |
if (U.compareAndSwapLong(this, CTL, c, c | STOP_BIT)) { |
1856 |
> |
for (int pass = 0; pass < 3; ++pass) { |
1857 |
> |
WorkQueue[] ws = workQueues; |
1858 |
> |
if (ws != null) { |
1859 |
> |
WorkQueue w; |
1860 |
> |
int n = ws.length; |
1861 |
> |
for (int i = 0; i < n; ++i) { |
1862 |
> |
if ((w = ws[i]) != null) { |
1863 |
> |
w.runState = -1; |
1864 |
> |
if (pass > 0) { |
1865 |
> |
w.cancelAll(); |
1866 |
> |
if (pass > 1) |
1867 |
> |
w.interruptOwner(); |
1868 |
|
} |
1869 |
|
} |
1870 |
|
} |
1871 |
< |
} |
1872 |
< |
} |
1873 |
< |
// Wake up workers parked on event queue |
1874 |
< |
int i, e; long c; Thread p; |
1875 |
< |
while ((i = ((~(e = (int)(c = ctl)) << 1) | 1) & SMASK) < n && |
1876 |
< |
(w = ws[i]) != null && |
1877 |
< |
w.eventCount == (e | INT_SIGN)) { |
1878 |
< |
long nc = ((long)(w.nextWait & E_MASK) | |
1879 |
< |
((c + AC_UNIT) & AC_MASK) | |
1880 |
< |
(c & (TC_MASK|STOP_BIT))); |
1881 |
< |
if (U.compareAndSwapLong(this, CTL, c, nc)) { |
1882 |
< |
w.eventCount = (e + E_SEQ) & E_MASK; |
1883 |
< |
if ((p = w.parker) != null) |
1884 |
< |
U.unpark(p); |
1871 |
> |
// Wake up workers parked on event queue |
1872 |
> |
int i, e; long cc; Thread p; |
1873 |
> |
while ((e = (int)(cc = ctl) & E_MASK) != 0 && |
1874 |
> |
(i = e & SMASK) < n && |
1875 |
> |
(w = ws[i]) != null) { |
1876 |
> |
long nc = ((long)(w.nextWait & E_MASK) | |
1877 |
> |
((cc + AC_UNIT) & AC_MASK) | |
1878 |
> |
(cc & (TC_MASK|STOP_BIT))); |
1879 |
> |
if (w.eventCount == (e | INT_SIGN) && |
1880 |
> |
U.compareAndSwapLong(this, CTL, cc, nc)) { |
1881 |
> |
w.eventCount = (e + E_SEQ) & E_MASK; |
1882 |
> |
w.runState = -1; |
1883 |
> |
if ((p = w.parker) != null) |
1884 |
> |
U.unpark(p); |
1885 |
> |
} |
1886 |
> |
} |
1887 |
|
} |
1888 |
|
} |
1889 |
|
} |
1959 |
|
checkPermission(); |
1960 |
|
if (factory == null) |
1961 |
|
throw new NullPointerException(); |
1962 |
< |
if (parallelism <= 0 || parallelism > MAX_ID) |
1962 |
> |
if (parallelism <= 0 || parallelism > POOL_MAX) |
1963 |
|
throw new IllegalArgumentException(); |
1964 |
|
this.parallelism = parallelism; |
1965 |
|
this.factory = factory; |
1966 |
|
this.ueh = handler; |
1967 |
|
this.localMode = asyncMode ? FIFO_QUEUE : LIFO_QUEUE; |
1968 |
< |
this.nextPoolIndex = 1; |
1968 |
> |
this.growHints = 1; |
1969 |
|
long np = (long)(-parallelism); // offset ctl counts |
1970 |
|
this.ctl = ((np << AC_SHIFT) & AC_MASK) | ((np << TC_SHIFT) & TC_MASK); |
1971 |
|
// initialize workQueues array with room for 2*parallelism if possible |
1972 |
|
int n = parallelism << 1; |
1973 |
< |
if (n >= MAX_ID) |
1974 |
< |
n = MAX_ID; |
1973 |
> |
if (n >= POOL_MAX) |
1974 |
> |
n = POOL_MAX; |
1975 |
|
else { // See Hackers Delight, sec 3.2, where n < (1 << 16) |
1976 |
|
n |= n >>> 1; n |= n >>> 2; n |= n >>> 4; n |= n >>> 8; |
1977 |
|
} |
1978 |
< |
this.workQueues = new WorkQueue[(n + 1) << 1]; |
1979 |
< |
ReentrantLock lck = this.lock = new ReentrantLock(); |
1967 |
< |
this.termination = lck.newCondition(); |
1978 |
> |
this.workQueues = new WorkQueue[(n + 1) << 1]; // #slots = 2 * #workers |
1979 |
> |
this.termination = (this.lock = new Mutex()).newCondition(); |
1980 |
|
this.stealCount = new AtomicLong(); |
1981 |
|
this.nextWorkerNumber = new AtomicInteger(); |
1982 |
|
StringBuilder sb = new StringBuilder("ForkJoinPool-"); |
1983 |
|
sb.append(poolNumberGenerator.incrementAndGet()); |
1984 |
|
sb.append("-worker-"); |
1985 |
|
this.workerNamePrefix = sb.toString(); |
1974 |
– |
// Create initial submission queue |
1975 |
– |
WorkQueue sq = tryAddSharedQueue(0); |
1976 |
– |
if (sq != null) |
1977 |
– |
sq.growArray(false); |
1986 |
|
} |
1987 |
|
|
1988 |
|
// Execution methods |
2100 |
|
* @throws RejectedExecutionException {@inheritDoc} |
2101 |
|
*/ |
2102 |
|
public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks) { |
2103 |
< |
ArrayList<ForkJoinTask<T>> forkJoinTasks = |
2104 |
< |
new ArrayList<ForkJoinTask<T>>(tasks.size()); |
2105 |
< |
for (Callable<T> task : tasks) |
2106 |
< |
forkJoinTasks.add(ForkJoinTask.adapt(task)); |
2107 |
< |
invoke(new InvokeAll<T>(forkJoinTasks)); |
2108 |
< |
|
2103 |
> |
// In previous versions of this class, this method constructed |
2104 |
> |
// a task to run ForkJoinTask.invokeAll, but now external |
2105 |
> |
// invocation of multiple tasks is at least as efficient. |
2106 |
> |
List<ForkJoinTask<T>> fs = new ArrayList<ForkJoinTask<T>>(tasks.size()); |
2107 |
> |
// Workaround needed because method wasn't declared with |
2108 |
> |
// wildcards in return type but should have been. |
2109 |
|
@SuppressWarnings({"unchecked", "rawtypes"}) |
2110 |
< |
List<Future<T>> futures = (List<Future<T>>) (List) forkJoinTasks; |
2103 |
< |
return futures; |
2104 |
< |
} |
2110 |
> |
List<Future<T>> futures = (List<Future<T>>) (List) fs; |
2111 |
|
|
2112 |
< |
static final class InvokeAll<T> extends RecursiveAction { |
2113 |
< |
final ArrayList<ForkJoinTask<T>> tasks; |
2114 |
< |
InvokeAll(ArrayList<ForkJoinTask<T>> tasks) { this.tasks = tasks; } |
2115 |
< |
public void compute() { |
2116 |
< |
try { invokeAll(tasks); } |
2117 |
< |
catch (Exception ignore) {} |
2112 |
> |
boolean done = false; |
2113 |
> |
try { |
2114 |
> |
for (Callable<T> t : tasks) { |
2115 |
> |
ForkJoinTask<T> f = ForkJoinTask.adapt(t); |
2116 |
> |
doSubmit(f); |
2117 |
> |
fs.add(f); |
2118 |
> |
} |
2119 |
> |
for (ForkJoinTask<T> f : fs) |
2120 |
> |
f.quietlyJoin(); |
2121 |
> |
done = true; |
2122 |
> |
return futures; |
2123 |
> |
} finally { |
2124 |
> |
if (!done) |
2125 |
> |
for (ForkJoinTask<T> f : fs) |
2126 |
> |
f.cancel(false); |
2127 |
|
} |
2113 |
– |
private static final long serialVersionUID = -7914297376763021607L; |
2128 |
|
} |
2129 |
|
|
2130 |
|
/** |
2189 |
|
int rc = 0; |
2190 |
|
WorkQueue[] ws; WorkQueue w; |
2191 |
|
if ((ws = workQueues) != null) { |
2192 |
< |
int n = ws.length; |
2193 |
< |
for (int i = 1; i < n; i += 2) { |
2180 |
< |
Thread.State s; ForkJoinWorkerThread wt; |
2181 |
< |
if ((w = ws[i]) != null && (wt = w.owner) != null && |
2182 |
< |
w.eventCount >= 0 && |
2183 |
< |
(s = wt.getState()) != Thread.State.BLOCKED && |
2184 |
< |
s != Thread.State.WAITING && |
2185 |
< |
s != Thread.State.TIMED_WAITING) |
2192 |
> |
for (int i = 1; i < ws.length; i += 2) { |
2193 |
> |
if ((w = ws[i]) != null && w.isApparentlyUnblocked()) |
2194 |
|
++rc; |
2195 |
|
} |
2196 |
|
} |
2239 |
|
long count = stealCount.get(); |
2240 |
|
WorkQueue[] ws; WorkQueue w; |
2241 |
|
if ((ws = workQueues) != null) { |
2242 |
< |
int n = ws.length; |
2235 |
< |
for (int i = 1; i < n; i += 2) { |
2242 |
> |
for (int i = 1; i < ws.length; i += 2) { |
2243 |
|
if ((w = ws[i]) != null) |
2244 |
|
count += w.totalSteals; |
2245 |
|
} |
2261 |
|
long count = 0; |
2262 |
|
WorkQueue[] ws; WorkQueue w; |
2263 |
|
if ((ws = workQueues) != null) { |
2264 |
< |
int n = ws.length; |
2258 |
< |
for (int i = 1; i < n; i += 2) { |
2264 |
> |
for (int i = 1; i < ws.length; i += 2) { |
2265 |
|
if ((w = ws[i]) != null) |
2266 |
|
count += w.queueSize(); |
2267 |
|
} |
2280 |
|
int count = 0; |
2281 |
|
WorkQueue[] ws; WorkQueue w; |
2282 |
|
if ((ws = workQueues) != null) { |
2283 |
< |
int n = ws.length; |
2278 |
< |
for (int i = 0; i < n; i += 2) { |
2283 |
> |
for (int i = 0; i < ws.length; i += 2) { |
2284 |
|
if ((w = ws[i]) != null) |
2285 |
|
count += w.queueSize(); |
2286 |
|
} |
2297 |
|
public boolean hasQueuedSubmissions() { |
2298 |
|
WorkQueue[] ws; WorkQueue w; |
2299 |
|
if ((ws = workQueues) != null) { |
2300 |
< |
int n = ws.length; |
2296 |
< |
for (int i = 0; i < n; i += 2) { |
2300 |
> |
for (int i = 0; i < ws.length; i += 2) { |
2301 |
|
if ((w = ws[i]) != null && w.queueSize() != 0) |
2302 |
|
return true; |
2303 |
|
} |
2315 |
|
protected ForkJoinTask<?> pollSubmission() { |
2316 |
|
WorkQueue[] ws; WorkQueue w; ForkJoinTask<?> t; |
2317 |
|
if ((ws = workQueues) != null) { |
2318 |
< |
int n = ws.length; |
2315 |
< |
for (int i = 0; i < n; i += 2) { |
2318 |
> |
for (int i = 0; i < ws.length; i += 2) { |
2319 |
|
if ((w = ws[i]) != null && (t = w.poll()) != null) |
2320 |
|
return t; |
2321 |
|
} |
2344 |
|
int count = 0; |
2345 |
|
WorkQueue[] ws; WorkQueue w; ForkJoinTask<?> t; |
2346 |
|
if ((ws = workQueues) != null) { |
2347 |
< |
int n = ws.length; |
2345 |
< |
for (int i = 0; i < n; ++i) { |
2347 |
> |
for (int i = 0; i < ws.length; ++i) { |
2348 |
|
if ((w = ws[i]) != null) { |
2349 |
|
while ((t = w.poll()) != null) { |
2350 |
|
c.add(t); |
2364 |
|
* @return a string identifying this pool, as well as its state |
2365 |
|
*/ |
2366 |
|
public String toString() { |
2367 |
< |
long st = getStealCount(); |
2368 |
< |
long qt = getQueuedTaskCount(); |
2369 |
< |
long qs = getQueuedSubmissionCount(); |
2368 |
< |
int rc = getRunningThreadCount(); |
2369 |
< |
int pc = parallelism; |
2367 |
> |
// Use a single pass through workQueues to collect counts |
2368 |
> |
long qt = 0L, qs = 0L; int rc = 0; |
2369 |
> |
long st = stealCount.get(); |
2370 |
|
long c = ctl; |
2371 |
+ |
WorkQueue[] ws; WorkQueue w; |
2372 |
+ |
if ((ws = workQueues) != null) { |
2373 |
+ |
for (int i = 0; i < ws.length; ++i) { |
2374 |
+ |
if ((w = ws[i]) != null) { |
2375 |
+ |
int size = w.queueSize(); |
2376 |
+ |
if ((i & 1) == 0) |
2377 |
+ |
qs += size; |
2378 |
+ |
else { |
2379 |
+ |
qt += size; |
2380 |
+ |
st += w.totalSteals; |
2381 |
+ |
if (w.isApparentlyUnblocked()) |
2382 |
+ |
++rc; |
2383 |
+ |
} |
2384 |
+ |
} |
2385 |
+ |
} |
2386 |
+ |
} |
2387 |
+ |
int pc = parallelism; |
2388 |
|
int tc = pc + (short)(c >>> TC_SHIFT); |
2389 |
|
int ac = pc + (int)(c >> AC_SHIFT); |
2390 |
|
if (ac < 0) // ignore transient negative |
2420 |
|
*/ |
2421 |
|
public void shutdown() { |
2422 |
|
checkPermission(); |
2423 |
< |
enableShutdown(); |
2407 |
< |
tryTerminate(false); |
2423 |
> |
tryTerminate(false, true); |
2424 |
|
} |
2425 |
|
|
2426 |
|
/** |
2441 |
|
*/ |
2442 |
|
public List<Runnable> shutdownNow() { |
2443 |
|
checkPermission(); |
2444 |
< |
enableShutdown(); |
2429 |
< |
tryTerminate(true); |
2444 |
> |
tryTerminate(true, true); |
2445 |
|
return Collections.emptyList(); |
2446 |
|
} |
2447 |
|
|
2498 |
|
public boolean awaitTermination(long timeout, TimeUnit unit) |
2499 |
|
throws InterruptedException { |
2500 |
|
long nanos = unit.toNanos(timeout); |
2501 |
< |
final ReentrantLock lock = this.lock; |
2501 |
> |
final Mutex lock = this.lock; |
2502 |
|
lock.lock(); |
2503 |
|
try { |
2504 |
|
for (;;) { |
2639 |
|
// Unsafe mechanics |
2640 |
|
private static final sun.misc.Unsafe U; |
2641 |
|
private static final long CTL; |
2627 |
– |
private static final long RUNSTATE; |
2642 |
|
private static final long PARKBLOCKER; |
2643 |
|
|
2644 |
|
static { |
2646 |
|
modifyThreadPermission = new RuntimePermission("modifyThread"); |
2647 |
|
defaultForkJoinWorkerThreadFactory = |
2648 |
|
new DefaultForkJoinWorkerThreadFactory(); |
2649 |
< |
int s; |
2649 |
> |
submitters = new ThreadSubmitter(); |
2650 |
|
try { |
2651 |
|
U = getUnsafe(); |
2652 |
|
Class<?> k = ForkJoinPool.class; |
2639 |
– |
Class<?> tk = Thread.class; |
2653 |
|
CTL = U.objectFieldOffset |
2654 |
|
(k.getDeclaredField("ctl")); |
2655 |
< |
RUNSTATE = U.objectFieldOffset |
2643 |
< |
(k.getDeclaredField("runState")); |
2655 |
> |
Class<?> tk = Thread.class; |
2656 |
|
PARKBLOCKER = U.objectFieldOffset |
2657 |
|
(tk.getDeclaredField("parkBlocker")); |
2658 |
|
} catch (Exception e) { |