[ViewVC] Diff of: jsr166/jsr166/src/jsr166e/ForkJoinPool.java

Comparing jsr166/src/jsr166e/ForkJoinPool.java (file contents):
Revision 1.35 by dl, Mon Dec 17 16:32:47 2012 UTC vs.
Revision 1.61 by jsr166, Sun Jul 14 19:55:05 2013 UTC

#	Line 6 \| Line 6
6
7		package jsr166e;
8
9	+	import java.lang.Thread.UncaughtExceptionHandler;
10		import java.util.ArrayList;
11		import java.util.Arrays;
12		import java.util.Collection;
#	Line 49 \| Line 50 \| import java.util.concurrent.TimeUnit;
50		* level; by default, equal to the number of available processors. The
51		* pool attempts to maintain enough active (or available) threads by
52		* dynamically adding, suspending, or resuming internal worker
53	<	* threads, even if some tasks are stalled waiting to join
54	<	* others. However, no such adjustments are guaranteed in the face of
55	<	* blocked I/O or other unmanaged synchronization. The nested {@link
53	>	* threads, even if some tasks are stalled waiting to join others.
54	>	* However, no such adjustments are guaranteed in the face of blocked
55	>	* I/O or other unmanaged synchronization. The nested {@link
56		* ManagedBlocker} interface enables extension of the kinds of
57		* synchronization accommodated.
58		*
#	Line 75 \| Line 76 \| import java.util.concurrent.TimeUnit;
76		* there is little difference among choice of methods.
77		*
78		* <table BORDER CELLPADDING=3 CELLSPACING=1>
79	+	* <caption>Summary of task execution methods</caption>
80		* <tr>
81		* <td></td>
82		* <td ALIGN=CENTER> <b>Call from non-fork/join clients</b></td>
83		* <td ALIGN=CENTER> <b>Call from within fork/join computations</b></td>
84		* </tr>
85		* <tr>
86	<	* <td> <b>Arrange async execution</td>
86	>	* <td> <b>Arrange async execution</b></td>
87		* <td> {@link #execute(ForkJoinTask)}</td>
88		* <td> {@link ForkJoinTask#fork}</td>
89		* </tr>
90		* <tr>
91	<	* <td> <b>Await and obtain result</td>
91	>	* <td> <b>Await and obtain result</b></td>
92		* <td> {@link #invoke(ForkJoinTask)}</td>
93		* <td> {@link ForkJoinTask#invoke}</td>
94		* </tr>
95		* <tr>
96	<	* <td> <b>Arrange exec and obtain Future</td>
96	>	* <td> <b>Arrange exec and obtain Future</b></td>
97		* <td> {@link #submit(ForkJoinTask)}</td>
98		* <td> {@link ForkJoinTask#fork} (ForkJoinTasks <em>are</em> Futures)</td>
99		* </tr>
100		* </table>
101		*
102		* <p>The common pool is by default constructed with default
103	<	* parameters, but these may be controlled by setting three {@link
104	<	* System#getProperty system properties} with prefix {@code
105	<	* java.util.concurrent.ForkJoinPool.common}: {@code parallelism} --
106	<	* an integer greater than zero, {@code threadFactory} -- the class
107	<	* name of a {@link ForkJoinWorkerThreadFactory}, and {@code
108	<	* exceptionHandler} -- the class name of a {@link
109	<	* java.lang.Thread.UncaughtExceptionHandler
110	<	* Thread.UncaughtExceptionHandler}. Upon any error in establishing
111	<	* these settings, default parameters are used.
103	>	* parameters, but these may be controlled by setting three
104	>	* {@linkplain System#getProperty system properties}:
105	>	* <ul>
106	>	* <li>{@code java.util.concurrent.ForkJoinPool.common.parallelism}
107	>	* - the parallelism level, a non-negative integer
108	>	* <li>{@code java.util.concurrent.ForkJoinPool.common.threadFactory}
109	>	* - the class name of a {@link ForkJoinWorkerThreadFactory}
110	>	* <li>{@code java.util.concurrent.ForkJoinPool.common.exceptionHandler}
111	>	* - the class name of a {@link UncaughtExceptionHandler}
112	>	* </ul>
113	>	* The system class loader is used to load these classes.
114	>	* Upon any error in establishing these settings, default parameters
115	>	* are used. It is possible to disable or limit the use of threads in
116	>	* the common pool by setting the parallelism property to zero, and/or
117	>	* using a factory that may return {@code null}.
118		*
119		* <p><b>Implementation notes</b>: This implementation restricts the
120		* maximum number of running threads to 32767. Attempts to create
#	Line 152 \| Line 160 \| public class ForkJoinPool extends Abstra
160		* (http://research.sun.com/scalable/pubs/index.html) and
161		* "Idempotent work stealing" by Michael, Saraswat, and Vechev,
162		* PPoPP 2009 (http://portal.acm.org/citation.cfm?id=1504186).
163	<	* The main differences ultimately stem from GC requirements that
164	<	* we null out taken slots as soon as we can, to maintain as small
165	<	* a footprint as possible even in programs generating huge
166	<	* numbers of tasks. To accomplish this, we shift the CAS
167	<	* arbitrating pop vs poll (steal) from being on the indices
168	<	* ("base" and "top") to the slots themselves. So, both a
169	<	* successful pop and poll mainly entail a CAS of a slot from
170	<	* non-null to null. Because we rely on CASes of references, we
171	<	* do not need tag bits on base or top. They are simple ints as
172	<	* used in any circular array-based queue (see for example
173	<	* ArrayDeque). Updates to the indices must still be ordered in a
174	<	* way that guarantees that top == base means the queue is empty,
175	<	* but otherwise may err on the side of possibly making the queue
176	<	* appear nonempty when a push, pop, or poll have not fully
177	<	* committed. Note that this means that the poll operation,
178	<	* considered individually, is not wait-free. One thief cannot
179	<	* successfully continue until another in-progress one (or, if
180	<	* previously empty, a push) completes. However, in the
181	<	* aggregate, we ensure at least probabilistic non-blockingness.
182	<	* If an attempted steal fails, a thief always chooses a different
183	<	* random victim target to try next. So, in order for one thief to
184	<	* progress, it suffices for any in-progress poll or new push on
185	<	* any empty queue to complete. (This is why we normally use
186	<	* method pollAt and its variants that try once at the apparent
187	<	* base index, else consider alternative actions, rather than
188	<	* method poll.)
163	>	* See also "Correct and Efficient Work-Stealing for Weak Memory
164	>	* Models" by Le, Pop, Cohen, and Nardelli, PPoPP 2013
165	>	* (http://www.di.ens.fr/~zappa/readings/ppopp13.pdf) for an
166	>	* analysis of memory ordering (atomic, volatile etc) issues. The
167	>	* main differences ultimately stem from GC requirements that we
168	>	* null out taken slots as soon as we can, to maintain as small a
169	>	* footprint as possible even in programs generating huge numbers
170	>	* of tasks. To accomplish this, we shift the CAS arbitrating pop
171	>	* vs poll (steal) from being on the indices ("base" and "top") to
172	>	* the slots themselves. So, both a successful pop and poll
173	>	* mainly entail a CAS of a slot from non-null to null. Because
174	>	* we rely on CASes of references, we do not need tag bits on base
175	>	* or top. They are simple ints as used in any circular
176	>	* array-based queue (see for example ArrayDeque). Updates to the
177	>	* indices must still be ordered in a way that guarantees that top
178	>	* == base means the queue is empty, but otherwise may err on the
179	>	* side of possibly making the queue appear nonempty when a push,
180	>	* pop, or poll have not fully committed. Note that this means
181	>	* that the poll operation, considered individually, is not
182	>	* wait-free. One thief cannot successfully continue until another
183	>	* in-progress one (or, if previously empty, a push) completes.
184	>	* However, in the aggregate, we ensure at least probabilistic
185	>	* non-blockingness. If an attempted steal fails, a thief always
186	>	* chooses a different random victim target to try next. So, in
187	>	* order for one thief to progress, it suffices for any
188	>	* in-progress poll or new push on any empty queue to
189	>	* complete. (This is why we normally use method pollAt and its
190	>	* variants that try once at the apparent base index, else
191	>	* consider alternative actions, rather than method poll.)
192		*
193		* This approach also enables support of a user mode in which local
194		* task processing is in FIFO, not LIFO order, simply by using
#	Line 196 \| Line 207 \| public class ForkJoinPool extends Abstra
207		* for work-stealing (this would contaminate lifo/fifo
208		* processing). Instead, we randomly associate submission queues
209		* with submitting threads, using a form of hashing. The
210	<	* ThreadLocal Submitter class contains a value initially used as
211	<	* a hash code for choosing existing queues, but may be randomly
212	<	* repositioned upon contention with other submitters. In
213	<	* essence, submitters act like workers except that they are
214	<	* restricted to executing local tasks that they submitted (or in
215	<	* the case of CountedCompleters, others with the same root task).
216	<	* However, because most shared/external queue operations are more
217	<	* expensive than internal, and because, at steady state, external
218	<	* submitters will compete for CPU with workers, ForkJoinTask.join
219	<	* and related methods disable them from repeatedly helping to
220	<	* process tasks if all workers are active. Insertion of tasks in
221	<	* shared mode requires a lock (mainly to protect in the case of
210	>	* Submitter probe value serves as a hash code for
211	>	* choosing existing queues, and may be randomly repositioned upon
212	>	* contention with other submitters. In essence, submitters act
213	>	* like workers except that they are restricted to executing local
214	>	* tasks that they submitted (or in the case of CountedCompleters,
215	>	* others with the same root task). However, because most
216	>	* shared/external queue operations are more expensive than
217	>	* internal, and because, at steady state, external submitters
218	>	* will compete for CPU with workers, ForkJoinTask.join and
219	>	* related methods disable them from repeatedly helping to process
220	>	* tasks if all workers are active. Insertion of tasks in shared
221	>	* mode requires a lock (mainly to protect in the case of
222		* resizing) but we use only a simple spinlock (using bits in
223		* field qlock), because submitters encountering a busy queue move
224		* on to try or create other queues -- they block only when
#	Line 297 \| Line 308 \| public class ForkJoinPool extends Abstra
308		* has not yet entered the wait queue. We solve this by requiring
309		* a full sweep of all workers (via repeated calls to method
310		* scan()) both before and after a newly waiting worker is added
311	<	* to the wait queue. During a rescan, the worker might release
312	<	* some other queued worker rather than itself, which has the same
313	<	* net effect. Because enqueued workers may actually be rescanning
314	<	* rather than waiting, we set and clear the "parker" field of
315	<	* WorkQueues to reduce unnecessary calls to unpark. (This
316	<	* requires a secondary recheck to avoid missed signals.) Note
317	<	* the unusual conventions about Thread.interrupts surrounding
318	<	* parking and other blocking: Because interrupts are used solely
319	<	* to alert threads to check termination, which is checked anyway
320	<	* upon blocking, we clear status (using Thread.interrupted)
321	<	* before any call to park, so that park does not immediately
311	<	* return due to status being set via some other unrelated call to
312	<	* interrupt in user code.
311	>	* to the wait queue. Because enqueued workers may actually be
312	>	* rescanning rather than waiting, we set and clear the "parker"
313	>	* field of WorkQueues to reduce unnecessary calls to unpark.
314	>	* (This requires a secondary recheck to avoid missed signals.)
315	>	* Note the unusual conventions about Thread.interrupts
316	>	* surrounding parking and other blocking: Because interrupts are
317	>	* used solely to alert threads to check termination, which is
318	>	* checked anyway upon blocking, we clear status (using
319	>	* Thread.interrupted) before any call to park, so that park does
320	>	* not immediately return due to status being set via some other
321	>	* unrelated call to interrupt in user code.
322		*
323		* Signalling. We create or wake up workers only when there
324		* appears to be at least one task they might be able to find and
325	<	* execute. However, many other threads may notice the same task
326	<	* and each signal to wake up a thread that might take it. So in
327	<	* general, pools will be over-signalled. When a submission is
328	<	* added or another worker adds a task to a queue that has fewer
329	<	* than two tasks, they signal waiting workers (or trigger
330	<	* creation of new ones if fewer than the given parallelism level
331	<	* -- signalWork), and may leave a hint to the unparked worker to
332	<	* help signal others upon wakeup). These primary signals are
324	<	* buttressed by others (see method helpSignal) whenever other
325	<	* threads scan for work or do not have a task to process. On
326	<	* most platforms, signalling (unpark) overhead time is noticeably
325	>	* execute. When a submission is added or another worker adds a
326	>	* task to a queue that has fewer than two tasks, they signal
327	>	* waiting workers (or trigger creation of new ones if fewer than
328	>	* the given parallelism level -- signalWork). These primary
329	>	* signals are buttressed by others whenever other threads remove
330	>	* a task from a queue and notice that there are other tasks there
331	>	* as well. So in general, pools will be over-signalled. On most
332	>	* platforms, signalling (unpark) overhead time is noticeably
333		* long, and the time between signalling a thread and it actually
334		* making progress can be very noticeably long, so it is worth
335		* offloading these delays from critical paths as much as
336	<	* possible.
336	>	* possible. Additionally, workers spin-down gradually, by staying
337	>	* alive so long as they see the ctl state changing. Similar
338	>	* stability-sensing techniques are also used before blocking in
339	>	* awaitJoin and helpComplete.
340		*
341		* Trimming workers. To release resources after periods of lack of
342		* use, a worker starting to wait when the pool is quiescent will
#	Line 440 \| Line 449 \| public class ForkJoinPool extends Abstra
449		* Common Pool
450		* ===========
451		*
452	<	* The static commonPool always exists after static
452	>	* The static common pool always exists after static
453		* initialization. Since it (or any other created pool) need
454		* never be used, we minimize initial construction overhead and
455		* footprint to the setup of about a dozen fields, with no nested
#	Line 448 \| Line 457 \| public class ForkJoinPool extends Abstra
457		* fullExternalPush during the first submission to the pool.
458		*
459		* When external threads submit to the common pool, they can
460	<	* perform some subtask processing (see externalHelpJoin and
461	<	* related methods). We do not need to record whether these
460	>	* perform subtask processing (see externalHelpJoin and related
461	>	* methods). This caller-helps policy makes it sensible to set
462	>	* common pool parallelism level to one (or more) less than the
463	>	* total number of available cores, or even zero for pure
464	>	* caller-runs. We do not need to record whether external
465		* submissions are to the common pool -- if not, externalHelpJoin
466		* returns quickly (at the most helping to signal some common pool
467		* workers). These submitters would otherwise be blocked waiting
#	Line 519 \| Line 531 \| public class ForkJoinPool extends Abstra
531		*
532		* @param pool the pool this thread works in
533		* @throws NullPointerException if the pool is null
534	+	* @return the new worker thread
535		*/
536		public ForkJoinWorkerThread newThread(ForkJoinPool pool);
537		}
#	Line 535 \| Line 548 \| public class ForkJoinPool extends Abstra
548		}
549
550		/**
538	–	* Per-thread records for threads that submit to pools. Currently
539	–	* holds only pseudo-random seed / index that is used to choose
540	–	* submission queues in method externalPush. In the future, this may
541	–	* also incorporate a means to implement different task rejection
542	–	* and resubmission policies.
543	–	*
544	–	* Seeds for submitters and workers/workQueues work in basically
545	–	* the same way but are initialized and updated using slightly
546	–	* different mechanics. Both are initialized using the same
547	–	* approach as in class ThreadLocal, where successive values are
548	–	* unlikely to collide with previous values. Seeds are then
549	–	* randomly modified upon collisions using xorshifts, which
550	–	* requires a non-zero seed.
551	–	*/
552	–	static final class Submitter {
553	–	int seed;
554	–	Submitter(int s) { seed = s; }
555	–	}
556	–
557	–	/**
551		* Class for artificial tasks that are used to replace the target
552		* of local joins if they are removed from an interior queue slot
553		* in WorkQueue.tryRemoveAndExec. We don't need the proxy to
#	Line 613 \| Line 606 \| public class ForkJoinPool extends Abstra
606		* do not want multiple WorkQueue instances or multiple queue
607		* arrays sharing cache lines. (It would be best for queue objects
608		* and their arrays to share, but there is nothing available to
609	<	* help arrange that). Unfortunately, because they are recorded
610	<	* in a common array, WorkQueue instances are often moved to be
618	<	* adjacent by garbage collectors. To reduce impact, we use field
619	<	* padding that works OK on common platforms; this effectively
620	<	* trades off slightly slower average field access for the sake of
621	<	* avoiding really bad worst-case access. (Until better JVM
622	<	* support is in place, this padding is dependent on transient
623	<	* properties of JVM field layout rules.) We also take care in
624	<	* allocating, sizing and resizing the array. Non-shared queue
625	<	* arrays are initialized by workers before use. Others are
626	<	* allocated on first use.
609	>	* help arrange that). The @Contended annotation alerts JVMs to
610	>	* try to keep instances apart.
611		*/
612		static final class WorkQueue {
613		/**
#	Line 649 \| Line 633 \| public class ForkJoinPool extends Abstra
633		// Heuristic padding to ameliorate unfortunate memory placements
634		volatile long pad00, pad01, pad02, pad03, pad04, pad05, pad06;
635
652	–	int seed; // for random scanning; initialize nonzero
636		volatile int eventCount; // encoded inactivation count; < 0 if inactive
637		int nextWait; // encoded record of next event waiter
655	–	int hint; // steal or signal hint (index)
656	–	int poolIndex; // index of this queue in pool (or 0)
657	–	final int mode; // 0: lifo, > 0: fifo, < 0: shared
638		int nsteals; // number of steals
639	+	int hint; // steal index hint
640	+	short poolIndex; // index of this queue in pool
641	+	final short mode; // 0: lifo, > 0: fifo, < 0: shared
642		volatile int qlock; // 1: locked, -1: terminate; else 0
643		volatile int base; // index of next slot for poll
644		int top; // index of next slot for push
#	Line 673 \| Line 656 \| public class ForkJoinPool extends Abstra
656		int seed) {
657		this.pool = pool;
658		this.owner = owner;
659	<	this.mode = mode;
660	<	this.seed = seed;
659	>	this.mode = (short)mode;
660	>	this.hint = seed; // store initial seed for runWorker
661		// Place indices in the center of array (that is not yet allocated)
662		base = top = INITIAL_QUEUE_CAPACITY >>> 1;
663		}
#	Line 687 \| Line 670 \| public class ForkJoinPool extends Abstra
670		return (n >= 0) ? 0 : -n; // ignore transient negative
671		}
672
673	<	/**
673	>	/**
674		* Provides a more accurate estimate of whether this queue has
675		* any tasks than does queueSize, by checking whether a
676		* near-empty queue has at least one unclaimed task.
#	Line 708 \| Line 691 \| public class ForkJoinPool extends Abstra
691		* shared-queue version is embedded in method externalPush.)
692		*
693		* @param task the task. Caller must ensure non-null.
694	<	* @throw RejectedExecutionException if array cannot be resized
694	>	* @throws RejectedExecutionException if array cannot be resized
695		*/
696		final void push(ForkJoinTask<?> task) {
697		ForkJoinTask<?>[] a; ForkJoinPool p;
698	<	int s = top, m, n;
698	>	int s = top, n;
699		if ((a = array) != null) { // ignore if queue removed
700	<	int j = (((m = a.length - 1) & s) << ASHIFT) + ABASE;
701	<	U.putOrderedObject(a, j, task);
702	<	if ((n = (top = s + 1) - base) <= 2) {
703	<	if ((p = pool) != null)
721	<	p.signalWork(this);
722	<	}
700	>	int m = a.length - 1;
701	>	U.putOrderedObject(a, ((m & s) << ASHIFT) + ABASE, task);
702	>	if ((n = (top = s + 1) - base) <= 2)
703	>	(p = pool).signalWork(p.workQueues, this);
704		else if (n >= m)
705		growArray();
706		}
707		}
708
709	<	/**
709	>	/**
710		* Initializes or doubles the capacity of array. Call either
711		* by owner or with lock held -- it is OK for base, but not
712		* top, to move while resizings are in progress.
#	Line 783 \| Line 764 \| public class ForkJoinPool extends Abstra
764		if ((a = array) != null) {
765		int j = (((a.length - 1) & b) << ASHIFT) + ABASE;
766		if ((t = (ForkJoinTask<?>)U.getObjectVolatile(a, j)) != null &&
767	<	base == b &&
768	<	U.compareAndSwapObject(a, j, t, null)) {
788	<	base = b + 1;
767	>	base == b && U.compareAndSwapObject(a, j, t, null)) {
768	>	U.putOrderedInt(this, QBASE, b + 1);
769		return t;
770		}
771		}
#	Line 801 \| Line 781 \| public class ForkJoinPool extends Abstra
781		int j = (((a.length - 1) & b) << ASHIFT) + ABASE;
782		t = (ForkJoinTask<?>)U.getObjectVolatile(a, j);
783		if (t != null) {
784	<	if (base == b &&
785	<	U.compareAndSwapObject(a, j, t, null)) {
806	<	base = b + 1;
784	>	if (U.compareAndSwapObject(a, j, t, null)) {
785	>	U.putOrderedInt(this, QBASE, b + 1);
786		return t;
787		}
788		}
#	Line 860 \| Line 839 \| public class ForkJoinPool extends Abstra
839		ForkJoinTask.cancelIgnoringExceptions(t);
840		}
841
863	–	/**
864	–	* Computes next value for random probes. Scans don't require
865	–	* a very high quality generator, but also not a crummy one.
866	–	* Marsaglia xor-shift is cheap and works well enough. Note:
867	–	* This is manually inlined in its usages in ForkJoinPool to
868	–	* avoid writes inside busy scan loops.
869	–	*/
870	–	final int nextSeed() {
871	–	int r = seed;
872	–	r ^= r << 13;
873	–	r ^= r >>> 17;
874	–	return seed = r ^= r << 5;
875	–	}
876	–
842		// Specialized execution methods
843
844		/**
845	<	* Pops and runs tasks until empty.
845	>	* Polls and runs tasks until empty.
846		*/
847	<	private void popAndExecAll() {
848	<	// A bit faster than repeated pop calls
849	<	ForkJoinTask<?>[] a; int m, s; long j; ForkJoinTask<?> t;
885	<	while ((a = array) != null && (m = a.length - 1) >= 0 &&
886	<	(s = top - 1) - base >= 0 &&
887	<	(t = ((ForkJoinTask<?>)
888	<	U.getObject(a, j = ((m & s) << ASHIFT) + ABASE)))
889	<	!= null) {
890	<	if (U.compareAndSwapObject(a, j, t, null)) {
891	<	top = s;
892	<	t.doExec();
893	<	}
894	<	}
847	>	final void pollAndExecAll() {
848	>	for (ForkJoinTask<?> t; (t = poll()) != null;)
849	>	t.doExec();
850		}
851
852		/**
853	<	* Polls and runs tasks until empty.
853	>	* Executes a top-level task and any local tasks remaining
854	>	* after execution.
855		*/
856	<	private void pollAndExecAll() {
857	<	for (ForkJoinTask<?> t; (t = poll()) != null;)
858	<	t.doExec();
856	>	final void runTask(ForkJoinTask<?> task) {
857	>	if ((currentSteal = task) != null) {
858	>	task.doExec();
859	>	ForkJoinTask<?>[] a = array;
860	>	int md = mode;
861	>	++nsteals;
862	>	currentSteal = null;
863	>	if (md != 0)
864	>	pollAndExecAll();
865	>	else if (a != null) {
866	>	int s, m = a.length - 1;
867	>	while ((s = top - 1) - base >= 0) {
868	>	long i = ((m & s) << ASHIFT) + ABASE;
869	>	ForkJoinTask<?> t = (ForkJoinTask<?>)U.getObject(a, i);
870	>	if (t == null)
871	>	break;
872	>	if (U.compareAndSwapObject(a, i, t, null)) {
873	>	top = s;
874	>	t.doExec();
875	>	}
876	>	}
877	>	}
878	>	}
879		}
880
881		/**
#	Line 907 \| Line 883 \| public class ForkJoinPool extends Abstra
883		* or any other cancelled task. Returns (true) on any CAS
884		* or consistency check failure so caller can retry.
885		*
886	<	* @return false if no progress can be made, else true;
886	>	* @return false if no progress can be made, else true
887		*/
888		final boolean tryRemoveAndExec(ForkJoinTask<?> task) {
889	<	boolean stat = true, removed = false, empty = true;
889	>	boolean stat;
890		ForkJoinTask<?>[] a; int m, s, b, n;
891	<	if ((a = array) != null && (m = a.length - 1) >= 0 &&
891	>	if (task != null && (a = array) != null && (m = a.length - 1) >= 0 &&
892		(n = (s = top) - (b = base)) > 0) {
893	+	boolean removed = false, empty = true;
894	+	stat = true;
895		for (ForkJoinTask<?> t;;) { // traverse from s to b
896	<	int j = ((--s & m) << ASHIFT) + ABASE;
897	<	t = (ForkJoinTask<?>)U.getObjectVolatile(a, j);
896	>	long j = ((--s & m) << ASHIFT) + ABASE;
897	>	t = (ForkJoinTask<?>)U.getObject(a, j);
898		if (t == null) // inconsistent length
899		break;
900		else if (t == task) {
#	Line 944 \| Line 922 \| public class ForkJoinPool extends Abstra
922		break;
923		}
924		}
925	+	if (removed)
926	+	task.doExec();
927		}
928	<	if (removed)
929	<	task.doExec();
928	>	else
929	>	stat = false;
930		return stat;
931		}
932
933		/**
934	<	* Polls for and executes the given task or any other task in
935	<	* its CountedCompleter computation
934	>	* Tries to poll for and execute the given task or any other
935	>	* task in its CountedCompleter computation.
936		*/
937	<	final boolean pollAndExecCC(ForkJoinTask<?> root) {
938	<	ForkJoinTask<?>[] a; int b; Object o;
939	<	outer: while ((b = base) - top < 0 && (a = array) != null) {
937	>	final boolean pollAndExecCC(CountedCompleter<?> root) {
938	>	ForkJoinTask<?>[] a; int b; Object o; CountedCompleter<?> t, r;
939	>	if ((b = base) - top < 0 && (a = array) != null) {
940		long j = (((a.length - 1) & b) << ASHIFT) + ABASE;
941	<	if ((o = U.getObject(a, j)) == null \|\|
942	<	!(o instanceof CountedCompleter))
943	<	break;
944	<	for (CountedCompleter<?> t = (CountedCompleter<?>)o, r = t;;) {
945	<	if (r == root) {
946	<	if (base == b &&
947	<	U.compareAndSwapObject(a, j, t, null)) {
948	<	base = b + 1;
949	<	t.doExec();
941	>	if ((o = U.getObjectVolatile(a, j)) == null)
942	>	return true; // retry
943	>	if (o instanceof CountedCompleter) {
944	>	for (t = (CountedCompleter<?>)o, r = t;;) {
945	>	if (r == root) {
946	>	if (base == b &&
947	>	U.compareAndSwapObject(a, j, t, null)) {
948	>	U.putOrderedInt(this, QBASE, b + 1);
949	>	t.doExec();
950	>	}
951		return true;
952		}
953	<	else
954	<	break; // restart
953	>	else if ((r = r.completer) == null)
954	>	break; // not part of root computation
955		}
975	–	if ((r = r.completer) == null)
976	–	break outer; // not part of root computation
956		}
957		}
958		return false;
959		}
960
961		/**
962	<	* Executes a top-level task and any local tasks remaining
963	<	* after execution.
962	>	* Tries to pop and execute the given task or any other task
963	>	* in its CountedCompleter computation.
964		*/
965	<	final void runTask(ForkJoinTask<?> t) {
966	<	if (t != null) {
967	<	(currentSteal = t).doExec();
968	<	currentSteal = null;
969	<	++nsteals;
970	<	if (base - top < 0) { // process remaining local tasks
971	<	if (mode == 0)
972	<	popAndExecAll();
973	<	else
974	<	pollAndExecAll();
965	>	final boolean externalPopAndExecCC(CountedCompleter<?> root) {
966	>	ForkJoinTask<?>[] a; int s; Object o; CountedCompleter<?> t, r;
967	>	if (base - (s = top) < 0 && (a = array) != null) {
968	>	long j = (((a.length - 1) & (s - 1)) << ASHIFT) + ABASE;
969	>	if ((o = U.getObject(a, j)) instanceof CountedCompleter) {
970	>	for (t = (CountedCompleter<?>)o, r = t;;) {
971	>	if (r == root) {
972	>	if (U.compareAndSwapInt(this, QLOCK, 0, 1)) {
973	>	if (top == s && array == a &&
974	>	U.compareAndSwapObject(a, j, t, null)) {
975	>	top = s - 1;
976	>	qlock = 0;
977	>	t.doExec();
978	>	}
979	>	else
980	>	qlock = 0;
981	>	}
982	>	return true;
983	>	}
984	>	else if ((r = r.completer) == null)
985	>	break;
986	>	}
987		}
988		}
989	+	return false;
990		}
991
992		/**
993	<	* Executes a non-top-level (stolen) task.
993	>	* Internal version
994		*/
995	<	final void runSubtask(ForkJoinTask<?> t) {
996	<	if (t != null) {
997	<	ForkJoinTask<?> ps = currentSteal;
998	<	(currentSteal = t).doExec();
999	<	currentSteal = ps;
995	>	final boolean internalPopAndExecCC(CountedCompleter<?> root) {
996	>	ForkJoinTask<?>[] a; int s; Object o; CountedCompleter<?> t, r;
997	>	if (base - (s = top) < 0 && (a = array) != null) {
998	>	long j = (((a.length - 1) & (s - 1)) << ASHIFT) + ABASE;
999	>	if ((o = U.getObject(a, j)) instanceof CountedCompleter) {
1000	>	for (t = (CountedCompleter<?>)o, r = t;;) {
1001	>	if (r == root) {
1002	>	if (U.compareAndSwapObject(a, j, t, null)) {
1003	>	top = s - 1;
1004	>	t.doExec();
1005	>	}
1006	>	return true;
1007	>	}
1008	>	else if ((r = r.completer) == null)
1009	>	break;
1010	>	}
1011	>	}
1012		}
1013	+	return false;
1014		}
1015
1016		/**
#	Line 1022 \| Line 1027 \| public class ForkJoinPool extends Abstra
1027
1028		// Unsafe mechanics
1029		private static final sun.misc.Unsafe U;
1030	+	private static final long QBASE;
1031		private static final long QLOCK;
1032		private static final int ABASE;
1033		private static final int ASHIFT;
1034		static {
1029	–	int s;
1035		try {
1036		U = getUnsafe();
1037		Class<?> k = WorkQueue.class;
1038		Class<?> ak = ForkJoinTask[].class;
1039	+	QBASE = U.objectFieldOffset
1040	+	(k.getDeclaredField("base"));
1041		QLOCK = U.objectFieldOffset
1042		(k.getDeclaredField("qlock"));
1043		ABASE = U.arrayBaseOffset(ak);
1044	<	s = U.arrayIndexScale(ak);
1044	>	int scale = U.arrayIndexScale(ak);
1045	>	if ((scale & (scale - 1)) != 0)
1046	>	throw new Error("data type scale not a power of two");
1047	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
1048		} catch (Exception e) {
1049		throw new Error(e);
1050		}
1041	–	if ((s & (s-1)) != 0)
1042	–	throw new Error("data type scale not a power of two");
1043	–	ASHIFT = 31 - Integer.numberOfLeadingZeros(s);
1051		}
1052		}
1053
1054		// static fields (initialized in static initializer below)
1055
1056		/**
1050	–	* Creates a new ForkJoinWorkerThread. This factory is used unless
1051	–	* overridden in ForkJoinPool constructors.
1052	–	*/
1053	–	public static final ForkJoinWorkerThreadFactory
1054	–	defaultForkJoinWorkerThreadFactory;
1055	–
1056	–	/**
1057		* Per-thread submission bookkeeping. Shared across all pools
1058		* to reduce ThreadLocal pollution and because random motion
1059		* to avoid contention in one pool is likely to hold for others.
#	Line 1063 \| Line 1063 \| public class ForkJoinPool extends Abstra
1063		static final ThreadLocal<Submitter> submitters;
1064
1065		/**
1066	+	* Creates a new ForkJoinWorkerThread. This factory is used unless
1067	+	* overridden in ForkJoinPool constructors.
1068	+	*/
1069	+	public static final ForkJoinWorkerThreadFactory
1070	+	defaultForkJoinWorkerThreadFactory;
1071	+
1072	+	/**
1073		* Permission required for callers of methods that may start or
1074		* kill threads.
1075		*/
#	Line 1074 \| Line 1081 \| public class ForkJoinPool extends Abstra
1081		* to paranoically avoid potential initialization circularities
1082		* as well as to simplify generated code.
1083		*/
1084	<	static final ForkJoinPool commonPool;
1084	>	static final ForkJoinPool common;
1085
1086		/**
1087	<	* Common pool parallelism. Must equal commonPool.parallelism.
1087	>	* Common pool parallelism. To allow simpler use and management
1088	>	* when common pool threads are disabled, we allow the underlying
1089	>	* common.parallelism field to be zero, but in that case still report
1090	>	* parallelism as 1 to reflect resulting caller-runs mechanics.
1091		*/
1092	<	static final int commonPoolParallelism;
1092	>	static final int commonParallelism;
1093
1094		/**
1095		* Sequence number for creating workerNamePrefix.
#	Line 1087 \| Line 1097 \| public class ForkJoinPool extends Abstra
1097		private static int poolNumberSequence;
1098
1099		/**
1100	<	* Return the next sequence number. We don't expect this to
1101	<	* ever contend so use simple builtin sync.
1100	>	* Returns the next sequence number. We don't expect this to
1101	>	* ever contend, so use simple builtin sync.
1102		*/
1103		private static final synchronized int nextPoolId() {
1104		return ++poolNumberSequence;
#	Line 1132 \| Line 1142 \| public class ForkJoinPool extends Abstra
1142		*/
1143		private static final int SEED_INCREMENT = 0x61c88647;
1144
1145	<	/**
1145	>	/*
1146		* Bits and masks for control variables
1147		*
1148		* Field ctl is a long packed with:
#	Line 1216 \| Line 1226 \| public class ForkJoinPool extends Abstra
1226		static final int FIFO_QUEUE = 1;
1227		static final int SHARED_QUEUE = -1;
1228
1219	–	// bounds for #steps in scan loop -- must be power 2 minus 1
1220	–	private static final int MIN_SCAN = 0x1ff; // cover estimation slop
1221	–	private static final int MAX_SCAN = 0x1ffff; // 4 * max workers
1222	–
1223	–	// Instance fields
1224	–
1225	–	/*
1226	–	* Field layout of this class tends to matter more than one would
1227	–	* like. Runtime layout order is only loosely related to
1228	–	* declaration order and may differ across JVMs, but the following
1229	–	* empirically works OK on current JVMs.
1230	–	*/
1231	–
1229		// Heuristic padding to ameliorate unfortunate memory placements
1230		volatile long pad00, pad01, pad02, pad03, pad04, pad05, pad06;
1231
1232	+	// Instance fields
1233		volatile long stealCount; // collects worker counts
1234		volatile long ctl; // main pool control
1235		volatile int plock; // shutdown status and seqLock
1236		volatile int indexSeed; // worker/submitter index seed
1237	<	final int config; // mode and parallelism level
1237	>	final short parallelism; // parallelism level
1238	>	final short mode; // LIFO/FIFO
1239		WorkQueue[] workQueues; // main registry
1240		final ForkJoinWorkerThreadFactory factory;
1241	<	final Thread.UncaughtExceptionHandler ueh; // per-worker UEH
1241	>	final UncaughtExceptionHandler ueh; // per-worker UEH
1242		final String workerNamePrefix; // to create worker name string
1243
1244		volatile Object pad10, pad11, pad12, pad13, pad14, pad15, pad16, pad17;
1245		volatile Object pad18, pad19, pad1a, pad1b;
1246
1247	<	/*
1247	>	/**
1248		* Acquires the plock lock to protect worker array and related
1249		* updates. This method is called only if an initial CAS on plock
1250	<	* fails. This acts as a spinLock for normal cases, but falls back
1250	>	* fails. This acts as a spinlock for normal cases, but falls back
1251		* to builtin monitor to block when (rarely) needed. This would be
1252		* a terrible idea for a highly contended lock, but works fine as
1253		* a more conservative alternative to a pure spinlock.
1254		*/
1255		private int acquirePlock() {
1256	<	int spins = PL_SPINS, r = 0, ps, nps;
1256	>	int spins = PL_SPINS, ps, nps;
1257		for (;;) {
1258		if (((ps = plock) & PL_LOCK) == 0 &&
1259		U.compareAndSwapInt(this, PLOCK, ps, nps = ps + PL_LOCK))
1260		return nps;
1262	–	else if (r == 0) { // randomize spins if possible
1263	–	Thread t = Thread.currentThread(); WorkQueue w; Submitter z;
1264	–	if ((t instanceof ForkJoinWorkerThread) &&
1265	–	(w = ((ForkJoinWorkerThread)t).workQueue) != null)
1266	–	r = w.seed;
1267	–	else if ((z = submitters.get()) != null)
1268	–	r = z.seed;
1269	–	else
1270	–	r = 1;
1271	–	}
1261		else if (spins >= 0) {
1262	<	r ^= r << 1; r ^= r >>> 3; r ^= r << 10; // xorshift
1274	<	if (r >= 0)
1262	>	if (ThreadLocalRandom.current().nextInt() >= 0)
1263		--spins;
1264		}
1265		else if (U.compareAndSwapInt(this, PLOCK, ps, ps \| PL_SIGNAL)) {
#	Line 1303 \| Line 1291 \| public class ForkJoinPool extends Abstra
1291		}
1292
1293		/**
1306	–	* Performs secondary initialization, called when plock is zero.
1307	–	* Creates workQueue array and sets plock to a valid value. The
1308	–	* lock body must be exception-free (so no try/finally) so we
1309	–	* optimistically allocate new array outside the lock and throw
1310	–	* away if (very rarely) not needed. (A similar tactic is used in
1311	–	* fullExternalPush.) Because the plock seq value can eventually
1312	–	* wrap around zero, this method harmlessly fails to reinitialize
1313	–	* if workQueues exists, while still advancing plock.
1314	–	*
1315	–	* Additionally tries to create the first worker.
1316	–	*/
1317	–	private void initWorkers() {
1318	–	WorkQueue[] ws, nws; int ps;
1319	–	int p = config & SMASK; // find power of two table size
1320	–	int n = (p > 1) ? p - 1 : 1; // ensure at least 2 slots
1321	–	n \|= n >>> 1; n \|= n >>> 2; n \|= n >>> 4; n \|= n >>> 8; n \|= n >>> 16;
1322	–	n = (n + 1) << 1;
1323	–	if ((ws = workQueues) == null \|\| ws.length == 0)
1324	–	nws = new WorkQueue[n];
1325	–	else
1326	–	nws = null;
1327	–	if (((ps = plock) & PL_LOCK) != 0 \|\|
1328	–	!U.compareAndSwapInt(this, PLOCK, ps, ps += PL_LOCK))
1329	–	ps = acquirePlock();
1330	–	if (((ws = workQueues) == null \|\| ws.length == 0) && nws != null)
1331	–	workQueues = nws;
1332	–	int nps = (ps & SHUTDOWN) \| ((ps + PL_LOCK) & ~SHUTDOWN);
1333	–	if (!U.compareAndSwapInt(this, PLOCK, ps, nps))
1334	–	releasePlock(nps);
1335	–	tryAddWorker();
1336	–	}
1337	–
1338	–	/**
1294		* Tries to create and start one worker if fewer than target
1295		* parallelism level exist. Adjusts counts etc on failure.
1296		*/
1297		private void tryAddWorker() {
1298	<	long c; int u;
1298	>	long c; int u, e;
1299		while ((u = (int)((c = ctl) >>> 32)) < 0 &&
1300	<	(u & SHORT_SIGN) != 0 && (int)c == 0) {
1301	<	long nc = (long)(((u + UTC_UNIT) & UTC_MASK) \|
1302	<	((u + UAC_UNIT) & UAC_MASK)) << 32;
1300	>	(u & SHORT_SIGN) != 0 && (e = (int)c) >= 0) {
1301	>	long nc = ((long)(((u + UTC_UNIT) & UTC_MASK) \|
1302	>	((u + UAC_UNIT) & UAC_MASK)) << 32) \| (long)e;
1303		if (U.compareAndSwapLong(this, CTL, c, nc)) {
1304		ForkJoinWorkerThreadFactory fac;
1305		Throwable ex = null;
#	Line 1355 \| Line 1310 \| public class ForkJoinPool extends Abstra
1310		wt.start();
1311		break;
1312		}
1313	<	} catch (Throwable e) {
1314	<	ex = e;
1313	>	} catch (Throwable rex) {
1314	>	ex = rex;
1315		}
1316		deregisterWorker(wt, ex);
1317		break;
#	Line 1377 \| Line 1332 \| public class ForkJoinPool extends Abstra
1332		* @return the worker's queue
1333		*/
1334		final WorkQueue registerWorker(ForkJoinWorkerThread wt) {
1335	<	Thread.UncaughtExceptionHandler handler; WorkQueue[] ws; int s, ps;
1335	>	UncaughtExceptionHandler handler; WorkQueue[] ws; int s, ps;
1336		wt.setDaemon(true);
1337		if ((handler = ueh) != null)
1338		wt.setUncaughtExceptionHandler(handler);
1339		do {} while (!U.compareAndSwapInt(this, INDEXSEED, s = indexSeed,
1340		s += SEED_INCREMENT) \|\|
1341		s == 0); // skip 0
1342	<	WorkQueue w = new WorkQueue(this, wt, config >>> 16, s);
1342	>	WorkQueue w = new WorkQueue(this, wt, mode, s);
1343		if (((ps = plock) & PL_LOCK) != 0 \|\|
1344		!U.compareAndSwapInt(this, PLOCK, ps, ps += PL_LOCK))
1345		ps = acquirePlock();
#	Line 1404 \| Line 1359 \| public class ForkJoinPool extends Abstra
1359		}
1360		}
1361		}
1362	<	w.eventCount = w.poolIndex = r; // volatile write orders
1362	>	w.poolIndex = (short)r;
1363	>	w.eventCount = r; // volatile write orders
1364		ws[r] = w;
1365		}
1366		} finally {
1367		if (!U.compareAndSwapInt(this, PLOCK, ps, nps))
1368		releasePlock(nps);
1369		}
1370	<	wt.setName(workerNamePrefix.concat(Integer.toString(w.poolIndex)));
1370	>	wt.setName(workerNamePrefix.concat(Integer.toString(w.poolIndex >>> 1)));
1371		return w;
1372		}
1373
#	Line 1421 \| Line 1377 \| public class ForkJoinPool extends Abstra
1377		* array, and adjusts counts. If pool is shutting down, tries to
1378		* complete termination.
1379		*
1380	<	* @param wt the worker thread or null if construction failed
1380	>	* @param wt the worker thread, or null if construction failed
1381		* @param ex the exception causing failure, or null if none
1382		*/
1383		final void deregisterWorker(ForkJoinWorkerThread wt, Throwable ex) {
1384		WorkQueue w = null;
1385		if (wt != null && (w = wt.workQueue) != null) {
1386	<	int ps;
1386	>	int ps; long sc;
1387		w.qlock = -1; // ensure set
1432	–	long ns = w.nsteals, sc; // collect steal count
1388		do {} while (!U.compareAndSwapLong(this, STEALCOUNT,
1389	<	sc = stealCount, sc + ns));
1389	>	sc = stealCount,
1390	>	sc + w.nsteals));
1391		if (((ps = plock) & PL_LOCK) != 0 \|\|
1392		!U.compareAndSwapInt(this, PLOCK, ps, ps += PL_LOCK))
1393		ps = acquirePlock();
#	Line 1460 \| Line 1416 \| public class ForkJoinPool extends Abstra
1416		if (e > 0) { // activate or create replacement
1417		if ((ws = workQueues) == null \|\|
1418		(i = e & SMASK) >= ws.length \|\|
1419	<	(v = ws[i]) != null)
1419	>	(v = ws[i]) == null)
1420		break;
1421		long nc = (((long)(v.nextWait & E_MASK)) \|
1422		((long)(u + UAC_UNIT) << 32));
#	Line 1489 \| Line 1445 \| public class ForkJoinPool extends Abstra
1445		// Submissions
1446
1447		/**
1448	+	* Per-thread records for threads that submit to pools. Currently
1449	+	* holds only pseudo-random seed / index that is used to choose
1450	+	* submission queues in method externalPush. In the future, this may
1451	+	* also incorporate a means to implement different task rejection
1452	+	* and resubmission policies.
1453	+	*
1454	+	* Seeds for submitters and workers/workQueues work in basically
1455	+	* the same way but are initialized and updated using slightly
1456	+	* different mechanics. Both are initialized using the same
1457	+	* approach as in class ThreadLocal, where successive values are
1458	+	* unlikely to collide with previous values. Seeds are then
1459	+	* randomly modified upon collisions using xorshifts, which
1460	+	* requires a non-zero seed.
1461	+	*/
1462	+	static final class Submitter {
1463	+	int seed;
1464	+	Submitter(int s) { seed = s; }
1465	+	}
1466	+
1467	+	/**
1468		* Unless shutting down, adds the given task to a submission queue
1469		* at submitter's current queue index (modulo submission
1470		* range). Only the most common path is directly handled in this
#	Line 1497 \| Line 1473 \| public class ForkJoinPool extends Abstra
1473		* @param task the task. Caller must ensure non-null.
1474		*/
1475		final void externalPush(ForkJoinTask<?> task) {
1476	<	WorkQueue[] ws; WorkQueue q; Submitter z; int m; ForkJoinTask<?>[] a;
1477	<	if ((z = submitters.get()) != null && plock > 0 &&
1478	<	(ws = workQueues) != null && (m = (ws.length - 1)) >= 0 &&
1479	<	(q = ws[m & z.seed & SQMASK]) != null &&
1476	>	Submitter z = submitters.get();
1477	>	WorkQueue q; int r, m, s, n, am; ForkJoinTask<?>[] a;
1478	>	int ps = plock;
1479	>	WorkQueue[] ws = workQueues;
1480	>	if (z != null && ps > 0 && ws != null && (m = (ws.length - 1)) >= 0 &&
1481	>	(q = ws[m & (r = z.seed) & SQMASK]) != null && r != 0 &&
1482		U.compareAndSwapInt(q, QLOCK, 0, 1)) { // lock
1483	<	int b = q.base, s = q.top, n, an;
1484	<	if ((a = q.array) != null && (an = a.length) > (n = s + 1 - b)) {
1485	<	int j = (((an - 1) & s) << ASHIFT) + ABASE;
1483	>	if ((a = q.array) != null &&
1484	>	(am = a.length - 1) > (n = (s = q.top) - q.base)) {
1485	>	int j = ((am & s) << ASHIFT) + ABASE;
1486		U.putOrderedObject(a, j, task);
1487		q.top = s + 1; // push on to deque
1488		q.qlock = 0;
1489	<	if (n <= 2)
1490	<	signalWork(q);
1489	>	if (n <= 1)
1490	>	signalWork(ws, q);
1491		return;
1492		}
1493		q.qlock = 0;
#	Line 1520 \| Line 1498 \| public class ForkJoinPool extends Abstra
1498		/**
1499		* Full version of externalPush. This method is called, among
1500		* other times, upon the first submission of the first task to the
1501	<	* pool, so must perform secondary initialization (via
1502	<	* initWorkers). It also detects first submission by an external
1503	<	* thread by looking up its ThreadLocal, and creates a new shared
1504	<	* queue if the one at index if empty or contended. The plock lock
1505	<	* body must be exception-free (so no try/finally) so we
1506	<	* optimistically allocate new queues outside the lock and throw
1507	<	* them away if (very rarely) not needed.
1501	>	* pool, so must perform secondary initialization. It also
1502	>	* detects first submission by an external thread by looking up
1503	>	* its ThreadLocal, and creates a new shared queue if the one at
1504	>	* index if empty or contended. The plock lock body must be
1505	>	* exception-free (so no try/finally) so we optimistically
1506	>	* allocate new queues outside the lock and throw them away if
1507	>	* (very rarely) not needed.
1508	>	*
1509	>	* Secondary initialization occurs when plock is zero, to create
1510	>	* workQueue array and set plock to a valid value. This lock body
1511	>	* must also be exception-free. Because the plock seq value can
1512	>	* eventually wrap around zero, this method harmlessly fails to
1513	>	* reinitialize if workQueues exists, while still advancing plock.
1514		*/
1515		private void fullExternalPush(ForkJoinTask<?> task) {
1516		int r = 0; // random index seed
#	Line 1537 \| Line 1521 \| public class ForkJoinPool extends Abstra
1521		r += SEED_INCREMENT) && r != 0)
1522		submitters.set(z = new Submitter(r));
1523		}
1524	<	else if (r == 0) { // move to a different index
1524	>	else if (r == 0) { // move to a different index
1525		r = z.seed;
1526	<	r ^= r << 13; // same xorshift as WorkQueues
1526	>	r ^= r << 13; // same xorshift as WorkQueues
1527		r ^= r >>> 17;
1528	<	z.seed = r ^ (r << 5);
1528	>	z.seed = r ^= (r << 5);
1529		}
1530	<	else if ((ps = plock) < 0)
1530	>	if ((ps = plock) < 0)
1531		throw new RejectedExecutionException();
1532		else if (ps == 0 \|\| (ws = workQueues) == null \|\|
1533	<	(m = ws.length - 1) < 0)
1534	<	initWorkers();
1533	>	(m = ws.length - 1) < 0) { // initialize workQueues
1534	>	int p = parallelism; // find power of two table size
1535	>	int n = (p > 1) ? p - 1 : 1; // ensure at least 2 slots
1536	>	n \|= n >>> 1; n \|= n >>> 2; n \|= n >>> 4;
1537	>	n \|= n >>> 8; n \|= n >>> 16; n = (n + 1) << 1;
1538	>	WorkQueue[] nws = ((ws = workQueues) == null \|\| ws.length == 0 ?
1539	>	new WorkQueue[n] : null);
1540	>	if (((ps = plock) & PL_LOCK) != 0 \|\|
1541	>	!U.compareAndSwapInt(this, PLOCK, ps, ps += PL_LOCK))
1542	>	ps = acquirePlock();
1543	>	if (((ws = workQueues) == null \|\| ws.length == 0) && nws != null)
1544	>	workQueues = nws;
1545	>	int nps = (ps & SHUTDOWN) \| ((ps + PL_LOCK) & ~SHUTDOWN);
1546	>	if (!U.compareAndSwapInt(this, PLOCK, ps, nps))
1547	>	releasePlock(nps);
1548	>	}
1549		else if ((q = ws[k = r & m & SQMASK]) != null) {
1550		if (q.qlock == 0 && U.compareAndSwapInt(q, QLOCK, 0, 1)) {
1551		ForkJoinTask<?>[] a = q.array;
#	Line 1565 \| Line 1563 \| public class ForkJoinPool extends Abstra
1563		q.qlock = 0; // unlock
1564		}
1565		if (submitted) {
1566	<	signalWork(q);
1566	>	signalWork(ws, q);
1567		return;
1568		}
1569		}
#	Line 1573 \| Line 1571 \| public class ForkJoinPool extends Abstra
1571		}
1572		else if (((ps = plock) & PL_LOCK) == 0) { // create new queue
1573		q = new WorkQueue(this, null, SHARED_QUEUE, r);
1574	+	q.poolIndex = (short)k;
1575		if (((ps = plock) & PL_LOCK) != 0 \|\|
1576		!U.compareAndSwapInt(this, PLOCK, ps, ps += PL_LOCK))
1577		ps = acquirePlock();
#	Line 1583 \| Line 1582 \| public class ForkJoinPool extends Abstra
1582		releasePlock(nps);
1583		}
1584		else
1585	<	r = 0; // try elsewhere while lock held
1585	>	r = 0;
1586		}
1587		}
1588
#	Line 1594 \| Line 1593 \| public class ForkJoinPool extends Abstra
1593		*/
1594		final void incrementActiveCount() {
1595		long c;
1596	<	do {} while (!U.compareAndSwapLong(this, CTL, c = ctl, c + AC_UNIT));
1596	>	do {} while (!U.compareAndSwapLong
1597	>	(this, CTL, c = ctl, ((c & ~AC_MASK) \|
1598	>	((c & AC_MASK) + AC_UNIT))));
1599		}
1600
1601		/**
1602		* Tries to create or activate a worker if too few are active.
1603		*
1604	<	* @param q the (non-null) queue holding tasks to be signalled
1604	>	* @param ws the worker array to use to find signallees
1605	>	* @param q if non-null, the queue holding tasks to be processed
1606		*/
1607	<	final void signalWork(WorkQueue q) {
1608	<	int hint = q.poolIndex;
1609	<	long c; int e, u, i, n; WorkQueue[] ws; WorkQueue w; Thread p;
1610	<	while ((u = (int)((c = ctl) >>> 32)) < 0) {
1611	<	if ((e = (int)c) > 0) {
1612	<	if ((ws = workQueues) != null && ws.length > (i = e & SMASK) &&
1611	<	(w = ws[i]) != null && w.eventCount == (e \| INT_SIGN)) {
1612	<	long nc = (((long)(w.nextWait & E_MASK)) \|
1613	<	((long)(u + UAC_UNIT) << 32));
1614	<	if (U.compareAndSwapLong(this, CTL, c, nc)) {
1615	<	w.hint = hint;
1616	<	w.eventCount = (e + E_SEQ) & E_MASK;
1617	<	if ((p = w.parker) != null)
1618	<	U.unpark(p);
1619	<	break;
1620	<	}
1621	<	if (q.top - q.base <= 0)
1622	<	break;
1623	<	}
1624	<	else
1625	<	break;
1626	<	}
1627	<	else {
1607	>	final void signalWork(WorkQueue[] ws, WorkQueue q) {
1608	>	for (;;) {
1609	>	long c; int e, u, i; WorkQueue w; Thread p;
1610	>	if ((u = (int)((c = ctl) >>> 32)) >= 0)
1611	>	break;
1612	>	if ((e = (int)c) <= 0) {
1613		if ((short)u < 0)
1614		tryAddWorker();
1615		break;
1616		}
1617	+	if (ws == null \|\| ws.length <= (i = e & SMASK) \|\|
1618	+	(w = ws[i]) == null)
1619	+	break;
1620	+	long nc = (((long)(w.nextWait & E_MASK)) \|
1621	+	((long)(u + UAC_UNIT)) << 32);
1622	+	int ne = (e + E_SEQ) & E_MASK;
1623	+	if (w.eventCount == (e \| INT_SIGN) &&
1624	+	U.compareAndSwapLong(this, CTL, c, nc)) {
1625	+	w.eventCount = ne;
1626	+	if ((p = w.parker) != null)
1627	+	U.unpark(p);
1628	+	break;
1629	+	}
1630	+	if (q != null && q.base >= q.top)
1631	+	break;
1632		}
1633		}
1634
#	Line 1639 \| Line 1639 \| public class ForkJoinPool extends Abstra
1639		*/
1640		final void runWorker(WorkQueue w) {
1641		w.growArray(); // allocate queue
1642	<	do { w.runTask(scan(w)); } while (w.qlock >= 0);
1642	>	for (int r = w.hint; scan(w, r) == 0; ) {
1643	>	r ^= r << 13; r ^= r >>> 17; r ^= r << 5; // xorshift
1644	>	}
1645		}
1646
1647		/**
1648	<	* Scans for and, if found, returns one task, else possibly
1648	>	* Scans for and, if found, runs one task, else possibly
1649		* inactivates the worker. This method operates on single reads of
1650		* volatile state and is designed to be re-invoked continuously,
1651		* in part because it returns upon detecting inconsistencies,
1652		* contention, or state changes that indicate possible success on
1653		* re-invocation.
1654		*
1655	<	* The scan searches for tasks across queues (starting at a random
1656	<	* index, and relying on registerWorker to irregularly scatter
1657	<	* them within array to avoid bias), checking each at least twice.
1658	<	* The scan terminates upon either finding a non-empty queue, or
1659	<	* completing the sweep. If the worker is not inactivated, it
1660	<	* takes and returns a task from this queue. Otherwise, if not
1661	<	* activated, it signals workers (that may include itself) and
1662	<	* returns so caller can retry. Also returns for true if the
1663	<	* worker array may have changed during an empty scan. On failure
1662	<	* to find a task, we take one of the following actions, after
1663	<	* which the caller will retry calling this method unless
1664	<	* terminated.
1665	<	*
1666	<	* * If pool is terminating, terminate the worker.
1667	<	*
1668	<	* * If not already enqueued, try to inactivate and enqueue the
1669	<	* worker on wait queue. Or, if inactivating has caused the pool
1670	<	* to be quiescent, relay to idleAwaitWork to possibly shrink
1671	<	* pool.
1672	<	*
1673	<	* * If already enqueued and none of the above apply, possibly
1674	<	* park awaiting signal, else lingering to help scan and signal.
1675	<	*
1676	<	* * If a non-empty queue discovered or left as a hint,
1677	<	* help wake up other workers before return
1655	>	* The scan searches for tasks across queues starting at a random
1656	>	* index, checking each at least twice. The scan terminates upon
1657	>	* either finding a non-empty queue, or completing the sweep. If
1658	>	* the worker is not inactivated, it takes and runs a task from
1659	>	* this queue. Otherwise, if not activated, it tries to activate
1660	>	* itself or some other worker by signalling. On failure to find a
1661	>	* task, returns (for retry) if pool state may have changed during
1662	>	* an empty scan, or tries to inactivate if active, else possibly
1663	>	* blocks or terminates via method awaitWork.
1664		*
1665		* @param w the worker (via its WorkQueue)
1666	<	* @return a task or null if none found
1666	>	* @param r a random seed
1667	>	* @return worker qlock status if would have waited, else 0
1668		*/
1669	<	private final ForkJoinTask<?> scan(WorkQueue w) {
1669	>	private final int scan(WorkQueue w, int r) {
1670		WorkQueue[] ws; int m;
1671	<	int ps = plock; // read plock before ws
1672	<	if (w != null && (ws = workQueues) != null && (m = ws.length - 1) >= 0) {
1673	<	int ec = w.eventCount; // ec is negative if inactive
1674	<	int r = w.seed; r ^= r << 13; r ^= r >>> 17; w.seed = r ^= r << 5;
1675	<	w.hint = -1; // update seed and clear hint
1676	<	int j = ((m + m + 1) \| MIN_SCAN) & MAX_SCAN;
1677	<	do {
1678	<	WorkQueue q; ForkJoinTask<?>[] a; int b;
1679	<	if ((q = ws[(r + j) & m]) != null && (b = q.base) - q.top < 0 &&
1680	<	(a = q.array) != null) { // probably nonempty
1681	<	int i = (((a.length - 1) & b) << ASHIFT) + ABASE;
1682	<	ForkJoinTask<?> t = (ForkJoinTask<?>)
1683	<	U.getObjectVolatile(a, i);
1684	<	if (q.base == b && ec >= 0 && t != null &&
1685	<	U.compareAndSwapObject(a, i, t, null)) {
1686	<	if ((q.base = b + 1) - q.top < 0)
1687	<	signalWork(q);
1688	<	return t; // taken
1689	<	}
1690	<	else if ((ec < 0 \|\| j < m) && (int)(ctl >> AC_SHIFT) <= 0) {
1691	<	w.hint = (r + j) & m; // help signal below
1692	<	break; // cannot take
1693	<	}
1694	<	}
1695	<	} while (--j >= 0);
1696	<
1697	<	int h, e, ns; long c, sc; WorkQueue q;
1711	<	if ((ns = w.nsteals) != 0) {
1712	<	if (U.compareAndSwapLong(this, STEALCOUNT,
1713	<	sc = stealCount, sc + ns))
1714	<	w.nsteals = 0; // collect steals and rescan
1715	<	}
1716	<	else if (plock != ps) // consistency check
1717	<	; // skip
1718	<	else if ((e = (int)(c = ctl)) < 0)
1719	<	w.qlock = -1; // pool is terminating
1720	<	else {
1721	<	if ((h = w.hint) < 0) {
1722	<	if (ec >= 0) { // try to enqueue/inactivate
1723	<	long nc = (((long)ec \|
1724	<	((c - AC_UNIT) & (AC_MASK\|TC_MASK))));
1725	<	w.nextWait = e; // link and mark inactive
1671	>	long c = ctl; // for consistency check
1672	>	if ((ws = workQueues) != null && (m = ws.length - 1) >= 0 && w != null) {
1673	>	for (int j = m + m + 1, ec = w.eventCount;;) {
1674	>	WorkQueue q; int b, e; ForkJoinTask<?>[] a; ForkJoinTask<?> t;
1675	>	if ((q = ws[(r - j) & m]) != null &&
1676	>	(b = q.base) - q.top < 0 && (a = q.array) != null) {
1677	>	long i = (((a.length - 1) & b) << ASHIFT) + ABASE;
1678	>	if ((t = ((ForkJoinTask<?>)
1679	>	U.getObjectVolatile(a, i))) != null) {
1680	>	if (ec < 0)
1681	>	helpRelease(c, ws, w, q, b);
1682	>	else if (q.base == b &&
1683	>	U.compareAndSwapObject(a, i, t, null)) {
1684	>	U.putOrderedInt(q, QBASE, b + 1);
1685	>	if ((b + 1) - q.top < 0)
1686	>	signalWork(ws, q);
1687	>	w.runTask(t);
1688	>	}
1689	>	}
1690	>	break;
1691	>	}
1692	>	else if (--j < 0) {
1693	>	if ((ec \| (e = (int)c)) < 0) // inactive or terminating
1694	>	return awaitWork(w, c, ec);
1695	>	else if (ctl == c) { // try to inactivate and enqueue
1696	>	long nc = (long)ec \| ((c - AC_UNIT) & (AC_MASK\|TC_MASK));
1697	>	w.nextWait = e;
1698		w.eventCount = ec \| INT_SIGN;
1699	<	if (ctl != c \|\| !U.compareAndSwapLong(this, CTL, c, nc))
1700	<	w.eventCount = ec; // unmark on CAS failure
1729	<	else if ((int)(c >> AC_SHIFT) == 1 - (config & SMASK))
1730	<	idleAwaitWork(w, nc, c);
1731	<	}
1732	<	else if (w.eventCount < 0 && !tryTerminate(false, false) &&
1733	<	ctl == c) { // block
1734	<	Thread wt = Thread.currentThread();
1735	<	Thread.interrupted(); // clear status
1736	<	U.putObject(wt, PARKBLOCKER, this);
1737	<	w.parker = wt; // emulate LockSupport.park
1738	<	if (w.eventCount < 0) // recheck
1739	<	U.park(false, 0L);
1740	<	w.parker = null;
1741	<	U.putObject(wt, PARKBLOCKER, null);
1742	<	}
1743	<	}
1744	<	if ((h >= 0 \|\| (h = w.hint) >= 0) &&
1745	<	(ws = workQueues) != null && h < ws.length &&
1746	<	(q = ws[h]) != null) { // signal others before retry
1747	<	WorkQueue v; Thread p; int u, i, s;
1748	<	for (int n = (config & SMASK) >>> 1;;) {
1749	<	int idleCount = (w.eventCount < 0) ? 0 : -1;
1750	<	if (((s = idleCount - q.base + q.top) <= n &&
1751	<	(n = s) <= 0) \|\|
1752	<	(u = (int)((c = ctl) >>> 32)) >= 0 \|\|
1753	<	(e = (int)c) <= 0 \|\| m < (i = e & SMASK) \|\|
1754	<	(v = ws[i]) == null)
1755	<	break;
1756	<	long nc = (((long)(v.nextWait & E_MASK)) \|
1757	<	((long)(u + UAC_UNIT) << 32));
1758	<	if (v.eventCount != (e \| INT_SIGN) \|\|
1759	<	!U.compareAndSwapLong(this, CTL, c, nc))
1760	<	break;
1761	<	v.hint = h;
1762	<	v.eventCount = (e + E_SEQ) & E_MASK;
1763	<	if ((p = v.parker) != null)
1764	<	U.unpark(p);
1765	<	if (--n <= 0)
1766	<	break;
1699	>	if (!U.compareAndSwapLong(this, CTL, c, nc))
1700	>	w.eventCount = ec; // back out
1701		}
1702	+	break;
1703		}
1704		}
1705		}
1706	<	return null;
1706	>	return 0;
1707		}
1708
1709		/**
1710	<	* If inactivating worker w has caused the pool to become
1711	<	* quiescent, checks for pool termination, and, so long as this is
1712	<	* not the only worker, waits for event for up to a given
1713	<	* duration. On timeout, if ctl has not changed, terminates the
1714	<	* worker, which will in turn wake up another worker to possibly
1715	<	* repeat this process.
1710	>	* A continuation of scan(), possibly blocking or terminating
1711	>	* worker w. Returns without blocking if pool state has apparently
1712	>	* changed since last invocation. Also, if inactivating w has
1713	>	* caused the pool to become quiescent, checks for pool
1714	>	* termination, and, so long as this is not the only worker, waits
1715	>	* for event for up to a given duration. On timeout, if ctl has
1716	>	* not changed, terminates the worker, which will in turn wake up
1717	>	* another worker to possibly repeat this process.
1718		*
1719		* @param w the calling worker
1720	<	* @param currentCtl the ctl value triggering possible quiescence
1721	<	* @param prevCtl the ctl value to restore if thread is terminated
1720	>	* @param c the ctl value on entry to scan
1721	>	* @param ec the worker's eventCount on entry to scan
1722		*/
1723	<	private void idleAwaitWork(WorkQueue w, long currentCtl, long prevCtl) {
1724	<	if (w != null && w.eventCount < 0 &&
1725	<	!tryTerminate(false, false) && (int)prevCtl != 0) {
1726	<	int dc = -(short)(currentCtl >>> TC_SHIFT);
1727	<	long parkTime = dc < 0 ? FAST_IDLE_TIMEOUT: (dc + 1) * IDLE_TIMEOUT;
1728	<	long deadline = System.nanoTime() + parkTime - TIMEOUT_SLOP;
1729	<	Thread wt = Thread.currentThread();
1730	<	while (ctl == currentCtl) {
1731	<	Thread.interrupted(); // timed variant of version in scan()
1732	<	U.putObject(wt, PARKBLOCKER, this);
1733	<	w.parker = wt;
1734	<	if (ctl == currentCtl)
1735	<	U.park(false, parkTime);
1736	<	w.parker = null;
1737	<	U.putObject(wt, PARKBLOCKER, null);
1738	<	if (ctl != currentCtl)
1739	<	break;
1740	<	if (deadline - System.nanoTime() <= 0L &&
1741	<	U.compareAndSwapLong(this, CTL, currentCtl, prevCtl)) {
1742	<	w.eventCount = (w.eventCount + E_SEQ) \| E_MASK;
1743	<	w.qlock = -1; // shrink
1744	<	break;
1723	>	private final int awaitWork(WorkQueue w, long c, int ec) {
1724	>	int stat, ns; long parkTime, deadline;
1725	>	if ((stat = w.qlock) >= 0 && w.eventCount == ec && ctl == c &&
1726	>	!Thread.interrupted()) {
1727	>	int e = (int)c;
1728	>	int u = (int)(c >>> 32);
1729	>	int d = (u >> UAC_SHIFT) + parallelism; // active count
1730	>
1731	>	if (e < 0 \|\| (d <= 0 && tryTerminate(false, false)))
1732	>	stat = w.qlock = -1; // pool is terminating
1733	>	else if ((ns = w.nsteals) != 0) { // collect steals and retry
1734	>	long sc;
1735	>	w.nsteals = 0;
1736	>	do {} while (!U.compareAndSwapLong(this, STEALCOUNT,
1737	>	sc = stealCount, sc + ns));
1738	>	}
1739	>	else {
1740	>	long pc = ((d > 0 \|\| ec != (e \| INT_SIGN)) ? 0L :
1741	>	((long)(w.nextWait & E_MASK)) \| // ctl to restore
1742	>	((long)(u + UAC_UNIT)) << 32);
1743	>	if (pc != 0L) { // timed wait if last waiter
1744	>	int dc = -(short)(c >>> TC_SHIFT);
1745	>	parkTime = (dc < 0 ? FAST_IDLE_TIMEOUT:
1746	>	(dc + 1) * IDLE_TIMEOUT);
1747	>	deadline = System.nanoTime() + parkTime - TIMEOUT_SLOP;
1748	>	}
1749	>	else
1750	>	parkTime = deadline = 0L;
1751	>	if (w.eventCount == ec && ctl == c) {
1752	>	Thread wt = Thread.currentThread();
1753	>	U.putObject(wt, PARKBLOCKER, this);
1754	>	w.parker = wt; // emulate LockSupport.park
1755	>	if (w.eventCount == ec && ctl == c)
1756	>	U.park(false, parkTime); // must recheck before park
1757	>	w.parker = null;
1758	>	U.putObject(wt, PARKBLOCKER, null);
1759	>	if (parkTime != 0L && ctl == c &&
1760	>	deadline - System.nanoTime() <= 0L &&
1761	>	U.compareAndSwapLong(this, CTL, c, pc))
1762	>	stat = w.qlock = -1; // shrink pool
1763		}
1764		}
1765		}
1766	+	return stat;
1767		}
1768
1769		/**
1770	<	* Scans through queues looking for work while joining a task; if
1771	<	* any present, signals. May return early if more signalling is
1772	<	* detectably unneeded.
1773	<	*
1774	<	* @param task return early if done
1775	<	* @param origin an index to start scan
1776	<	*/
1777	<	private void helpSignal(ForkJoinTask<?> task, int origin) {
1778	<	WorkQueue[] ws; WorkQueue w; Thread p; long c; int m, u, e, i, s;
1779	<	if (task != null && task.status >= 0 &&
1780	<	(u = (int)(ctl >>> 32)) < 0 && (u >> UAC_SHIFT) < 0 &&
1781	<	(ws = workQueues) != null && (m = ws.length - 1) >= 0) {
1782	<	outer: for (int k = origin, j = m; j >= 0; --j) {
1783	<	WorkQueue q = ws[k++ & m];
1784	<	for (int n = m;;) { // limit to at most m signals
1785	<	if (task.status < 0)
1786	<	break outer;
1787	<	if (q == null \|\|
1788	<	((s = -q.base + q.top) <= n && (n = s) <= 0))
1789	<	break;
1834	<	if ((u = (int)((c = ctl) >>> 32)) >= 0 \|\|
1835	<	(e = (int)c) <= 0 \|\| m < (i = e & SMASK) \|\|
1836	<	(w = ws[i]) == null)
1837	<	break outer;
1838	<	long nc = (((long)(w.nextWait & E_MASK)) \|
1839	<	((long)(u + UAC_UNIT) << 32));
1840	<	if (w.eventCount != (e \| INT_SIGN))
1841	<	break outer;
1842	<	if (U.compareAndSwapLong(this, CTL, c, nc)) {
1843	<	w.eventCount = (e + E_SEQ) & E_MASK;
1844	<	if ((p = w.parker) != null)
1845	<	U.unpark(p);
1846	<	if (--n <= 0)
1847	<	break;
1848	<	}
1849	<	}
1770	>	* Possibly releases (signals) a worker. Called only from scan()
1771	>	* when a worker with apparently inactive status finds a non-empty
1772	>	* queue. This requires revalidating all of the associated state
1773	>	* from caller.
1774	>	*/
1775	>	private final void helpRelease(long c, WorkQueue[] ws, WorkQueue w,
1776	>	WorkQueue q, int b) {
1777	>	WorkQueue v; int e, i; Thread p;
1778	>	if (w != null && w.eventCount < 0 && (e = (int)c) > 0 &&
1779	>	ws != null && ws.length > (i = e & SMASK) &&
1780	>	(v = ws[i]) != null && ctl == c) {
1781	>	long nc = (((long)(v.nextWait & E_MASK)) \|
1782	>	((long)((int)(c >>> 32) + UAC_UNIT)) << 32);
1783	>	int ne = (e + E_SEQ) & E_MASK;
1784	>	if (q != null && q.base == b && w.eventCount < 0 &&
1785	>	v.eventCount == (e \| INT_SIGN) &&
1786	>	U.compareAndSwapLong(this, CTL, c, nc)) {
1787	>	v.eventCount = ne;
1788	>	if ((p = v.parker) != null)
1789	>	U.unpark(p);
1790		}
1791		}
1792		}
#	Line 1871 \| Line 1811 \| public class ForkJoinPool extends Abstra
1811		*/
1812		private int tryHelpStealer(WorkQueue joiner, ForkJoinTask<?> task) {
1813		int stat = 0, steps = 0; // bound to avoid cycles
1814	<	if (joiner != null && task != null) { // hoist null checks
1814	>	if (task != null && joiner != null &&
1815	>	joiner.base - joiner.top >= 0) { // hoist checks
1816		restart: for (;;) {
1817		ForkJoinTask<?> subtask = task; // current target
1818		for (WorkQueue j = joiner, v;;) { // v is stealer of subtask
#	Line 1898 \| Line 1839 \| public class ForkJoinPool extends Abstra
1839		}
1840		}
1841		for (;;) { // help stealer or descend to its stealer
1842	<	ForkJoinTask[] a; int b;
1842	>	ForkJoinTask[] a; int b;
1843		if (subtask.status < 0) // surround probes with
1844		continue restart; // consistency checks
1845		if ((b = v.base) - v.top < 0 && (a = v.array) != null) {
#	Line 1909 \| Line 1850 \| public class ForkJoinPool extends Abstra
1850		v.currentSteal != subtask)
1851		continue restart; // stale
1852		stat = 1; // apparent progress
1853	<	if (t != null && v.base == b &&
1854	<	U.compareAndSwapObject(a, i, t, null)) {
1855	<	v.base = b + 1; // help stealer
1856	<	joiner.runSubtask(t);
1853	>	if (v.base == b) {
1854	>	if (t == null)
1855	>	break restart;
1856	>	if (U.compareAndSwapObject(a, i, t, null)) {
1857	>	U.putOrderedInt(v, QBASE, b + 1);
1858	>	ForkJoinTask<?> ps = joiner.currentSteal;
1859	>	int jt = joiner.top;
1860	>	do {
1861	>	joiner.currentSteal = t;
1862	>	t.doExec(); // clear local tasks too
1863	>	} while (task.status >= 0 &&
1864	>	joiner.top != jt &&
1865	>	(t = joiner.pop()) != null);
1866	>	joiner.currentSteal = ps;
1867	>	break restart;
1868	>	}
1869		}
1917	–	else if (v.base == b && ++steps == MAX_HELP)
1918	–	break restart; // v apparently stalled
1870		}
1871		else { // empty -- try to descend
1872		ForkJoinTask<?> next = v.currentJoin;
#	Line 1942 \| Line 1893 \| public class ForkJoinPool extends Abstra
1893		* and run tasks within the target's computation.
1894		*
1895		* @param task the task to join
1945	–	* @param mode if shared, exit upon completing any task
1946	–	* if all workers are active
1947	–	*
1896		*/
1897	<	private int helpComplete(ForkJoinTask<?> task, int mode) {
1898	<	WorkQueue[] ws; WorkQueue q; int m, n, s, u;
1899	<	if (task != null && (ws = workQueues) != null &&
1900	<	(m = ws.length - 1) >= 0) {
1901	<	for (int j = 1, origin = j;;) {
1897	>	private int helpComplete(WorkQueue joiner, CountedCompleter<?> task) {
1898	>	WorkQueue[] ws; int m;
1899	>	int s = 0;
1900	>	if ((ws = workQueues) != null && (m = ws.length - 1) >= 0 &&
1901	>	joiner != null && task != null) {
1902	>	int j = joiner.poolIndex;
1903	>	int scans = m + m + 1;
1904	>	long c = 0L; // for stability check
1905	>	for (int k = scans; ; j += 2) {
1906	>	WorkQueue q;
1907		if ((s = task.status) < 0)
1908	<	return s;
1909	<	if ((q = ws[j & m]) != null && q.pollAndExecCC(task)) {
1910	<	origin = j;
1911	<	if (mode == SHARED_QUEUE &&
1912	<	((u = (int)(ctl >>> 32)) >= 0 \|\| (u >> UAC_SHIFT) >= 0))
1908	>	break;
1909	>	else if (joiner.internalPopAndExecCC(task))
1910	>	k = scans;
1911	>	else if ((s = task.status) < 0)
1912	>	break;
1913	>	else if ((q = ws[j & m]) != null && q.pollAndExecCC(task))
1914	>	k = scans;
1915	>	else if (--k < 0) {
1916	>	if (c == (c = ctl))
1917		break;
1918	+	k = scans;
1919		}
1962	–	else if ((j = (j + 2) & m) == origin)
1963	–	break;
1920		}
1921		}
1922	<	return 0;
1922	>	return s;
1923		}
1924
1925		/**
#	Line 1972 \| Line 1928 \| public class ForkJoinPool extends Abstra
1928		* for blocking. Fails on contention or termination. Otherwise,
1929		* adds a new thread if no idle workers are available and pool
1930		* may become starved.
1931	+	*
1932	+	* @param c the assumed ctl value
1933		*/
1934	<	final boolean tryCompensate() {
1935	<	int pc = config & SMASK, e, i, tc; long c;
1936	<	WorkQueue[] ws; WorkQueue w; Thread p;
1937	<	if ((ws = workQueues) != null && (e = (int)(c = ctl)) >= 0) {
1938	<	if (e != 0 && (i = e & SMASK) < ws.length &&
1939	<	(w = ws[i]) != null && w.eventCount == (e \| INT_SIGN)) {
1934	>	final boolean tryCompensate(long c) {
1935	>	WorkQueue[] ws = workQueues;
1936	>	int pc = parallelism, e = (int)c, m, tc;
1937	>	if (ws != null && (m = ws.length - 1) >= 0 && e >= 0 && ctl == c) {
1938	>	WorkQueue w = ws[e & m];
1939	>	if (e != 0 && w != null) {
1940	>	Thread p;
1941		long nc = ((long)(w.nextWait & E_MASK) \|
1942		(c & (AC_MASK\|TC_MASK)));
1943	<	if (U.compareAndSwapLong(this, CTL, c, nc)) {
1944	<	w.eventCount = (e + E_SEQ) & E_MASK;
1943	>	int ne = (e + E_SEQ) & E_MASK;
1944	>	if (w.eventCount == (e \| INT_SIGN) &&
1945	>	U.compareAndSwapLong(this, CTL, c, nc)) {
1946	>	w.eventCount = ne;
1947		if ((p = w.parker) != null)
1948		U.unpark(p);
1949		return true; // replace with idle worker
#	Line 2025 \| Line 1986 \| public class ForkJoinPool extends Abstra
1986		*/
1987		final int awaitJoin(WorkQueue joiner, ForkJoinTask<?> task) {
1988		int s = 0;
1989	<	if (joiner != null && task != null && (s = task.status) >= 0) {
1989	>	if (task != null && (s = task.status) >= 0 && joiner != null) {
1990		ForkJoinTask<?> prevJoin = joiner.currentJoin;
1991		joiner.currentJoin = task;
1992	<	do {} while ((s = task.status) >= 0 && !joiner.isEmpty() &&
1993	<	joiner.tryRemoveAndExec(task)); // process local tasks
1994	<	if (s >= 0 && (s = task.status) >= 0) {
1995	<	helpSignal(task, joiner.poolIndex);
1996	<	if ((s = task.status) >= 0 &&
2036	<	(task instanceof CountedCompleter))
2037	<	s = helpComplete(task, LIFO_QUEUE);
2038	<	}
1992	>	do {} while (joiner.tryRemoveAndExec(task) && // process local tasks
1993	>	(s = task.status) >= 0);
1994	>	if (s >= 0 && (task instanceof CountedCompleter))
1995	>	s = helpComplete(joiner, (CountedCompleter<?>)task);
1996	>	long cc = 0; // for stability checks
1997		while (s >= 0 && (s = task.status) >= 0) {
1998	<	if ((!joiner.isEmpty() \|\| // try helping
2041	<	(s = tryHelpStealer(joiner, task)) == 0) &&
1998	>	if ((s = tryHelpStealer(joiner, task)) == 0 &&
1999		(s = task.status) >= 0) {
2000	<	helpSignal(task, joiner.poolIndex);
2001	<	if ((s = task.status) >= 0 && tryCompensate()) {
2000	>	if (!tryCompensate(cc))
2001	>	cc = ctl;
2002	>	else {
2003		if (task.trySetSignal() && (s = task.status) >= 0) {
2004		synchronized (task) {
2005		if (task.status >= 0) {
#	Line 2054 \| Line 2012 \| public class ForkJoinPool extends Abstra
2012		task.notifyAll();
2013		}
2014		}
2015	<	long c; // re-activate
2015	>	long c; // reactivate
2016		do {} while (!U.compareAndSwapLong
2017	<	(this, CTL, c = ctl, c + AC_UNIT));
2017	>	(this, CTL, c = ctl,
2018	>	((c & ~AC_MASK) \|
2019	>	((c & AC_MASK) + AC_UNIT))));
2020		}
2021		}
2022		}
#	Line 2078 \| Line 2038 \| public class ForkJoinPool extends Abstra
2038		if (joiner != null && task != null && (s = task.status) >= 0) {
2039		ForkJoinTask<?> prevJoin = joiner.currentJoin;
2040		joiner.currentJoin = task;
2041	<	do {} while ((s = task.status) >= 0 && !joiner.isEmpty() &&
2042	<	joiner.tryRemoveAndExec(task));
2043	<	if (s >= 0 && (s = task.status) >= 0) {
2044	<	helpSignal(task, joiner.poolIndex);
2045	<	if ((s = task.status) >= 0 &&
2086	<	(task instanceof CountedCompleter))
2087	<	s = helpComplete(task, LIFO_QUEUE);
2088	<	}
2089	<	if (s >= 0 && joiner.isEmpty()) {
2041	>	do {} while (joiner.tryRemoveAndExec(task) && // process local tasks
2042	>	(s = task.status) >= 0);
2043	>	if (s >= 0) {
2044	>	if (task instanceof CountedCompleter)
2045	>	helpComplete(joiner, (CountedCompleter<?>)task);
2046		do {} while (task.status >= 0 &&
2047		tryHelpStealer(joiner, task) > 0);
2048		}
#	Line 2096 \| Line 2052 \| public class ForkJoinPool extends Abstra
2052
2053		/**
2054		* Returns a (probably) non-empty steal queue, if one is found
2055	<	* during a random, then cyclic scan, else null. This method must
2056	<	* be retried by caller if, by the time it tries to use the queue,
2057	<	* it is empty.
2058	<	* @param r a (random) seed for scanning
2059	<	*/
2060	<	private WorkQueue findNonEmptyStealQueue(int r) {
2061	<	for (WorkQueue[] ws;;) {
2062	<	int ps = plock, m, n;
2063	<	if ((ws = workQueues) == null \|\| (m = ws.length - 1) < 1)
2064	<	return null;
2065	<	for (int j = (m + 1) << 2; ;) {
2066	<	WorkQueue q = ws[(((r + j) << 1) \| 1) & m];
2111	<	if (q != null && (n = q.base - q.top) < 0) {
2112	<	if (n < -1)
2113	<	signalWork(q);
2114	<	return q;
2115	<	}
2116	<	else if (--j < 0) {
2117	<	if (plock == ps)
2118	<	return null;
2119	<	break;
2055	>	* during a scan, else null. This method must be retried by
2056	>	* caller if, by the time it tries to use the queue, it is empty.
2057	>	*/
2058	>	private WorkQueue findNonEmptyStealQueue() {
2059	>	int r = ThreadLocalRandom.current().nextInt();
2060	>	for (;;) {
2061	>	int ps = plock, m; WorkQueue[] ws; WorkQueue q;
2062	>	if ((ws = workQueues) != null && (m = ws.length - 1) >= 0) {
2063	>	for (int j = (m + 1) << 2; j >= 0; --j) {
2064	>	if ((q = ws[(((r - j) << 1) \| 1) & m]) != null &&
2065	>	q.base - q.top < 0)
2066	>	return q;
2067		}
2068		}
2069	+	if (plock == ps)
2070	+	return null;
2071		}
2072		}
2073
#	Line 2129 \| Line 2078 \| public class ForkJoinPool extends Abstra
2078		* find tasks either.
2079		*/
2080		final void helpQuiescePool(WorkQueue w) {
2081	+	ForkJoinTask<?> ps = w.currentSteal;
2082		for (boolean active = true;;) {
2083	<	ForkJoinTask<?> localTask; // exhaust local queue
2084	<	while ((localTask = w.nextLocalTask()) != null)
2085	<	localTask.doExec();
2086	<	// Similar to loop in scan(), but ignoring submissions
2137	<	WorkQueue q = findNonEmptyStealQueue(w.nextSeed());
2138	<	if (q != null) {
2139	<	ForkJoinTask<?> t; int b;
2083	>	long c; WorkQueue q; ForkJoinTask<?> t; int b;
2084	>	while ((t = w.nextLocalTask()) != null)
2085	>	t.doExec();
2086	>	if ((q = findNonEmptyStealQueue()) != null) {
2087		if (!active) { // re-establish active count
2141	–	long c;
2088		active = true;
2089		do {} while (!U.compareAndSwapLong
2090	<	(this, CTL, c = ctl, c + AC_UNIT));
2090	>	(this, CTL, c = ctl,
2091	>	((c & ~AC_MASK) \|
2092	>	((c & AC_MASK) + AC_UNIT))));
2093	>	}
2094	>	if ((b = q.base) - q.top < 0 && (t = q.pollAt(b)) != null) {
2095	>	(w.currentSteal = t).doExec();
2096	>	w.currentSteal = ps;
2097		}
2146	–	if ((b = q.base) - q.top < 0 && (t = q.pollAt(b)) != null)
2147	–	w.runSubtask(t);
2098		}
2099	<	else {
2100	<	long c;
2101	<	if (active) { // decrement active count without queuing
2099	>	else if (active) { // decrement active count without queuing
2100	>	long nc = ((c = ctl) & ~AC_MASK) \| ((c & AC_MASK) - AC_UNIT);
2101	>	if ((int)(nc >> AC_SHIFT) + parallelism == 0)
2102	>	break; // bypass decrement-then-increment
2103	>	if (U.compareAndSwapLong(this, CTL, c, nc))
2104		active = false;
2153	–	do {} while (!U.compareAndSwapLong
2154	–	(this, CTL, c = ctl, c -= AC_UNIT));
2155	–	}
2156	–	else
2157	–	c = ctl; // re-increment on exit
2158	–	if ((int)(c >> AC_SHIFT) + (config & SMASK) == 0) {
2159	–	do {} while (!U.compareAndSwapLong
2160	–	(this, CTL, c = ctl, c + AC_UNIT));
2161	–	break;
2162	–	}
2105		}
2106	+	else if ((int)((c = ctl) >> AC_SHIFT) + parallelism <= 0 &&
2107	+	U.compareAndSwapLong
2108	+	(this, CTL, c, ((c & ~AC_MASK) \|
2109	+	((c & AC_MASK) + AC_UNIT))))
2110	+	break;
2111		}
2112		}
2113
#	Line 2174 \| Line 2121 \| public class ForkJoinPool extends Abstra
2121		WorkQueue q; int b;
2122		if ((t = w.nextLocalTask()) != null)
2123		return t;
2124	<	if ((q = findNonEmptyStealQueue(w.nextSeed())) == null)
2124	>	if ((q = findNonEmptyStealQueue()) == null)
2125		return null;
2126		if ((b = q.base) - q.top < 0 && (t = q.pollAt(b)) != null)
2127		return t;
#	Line 2206 \| Line 2153 \| public class ForkJoinPool extends Abstra
2153		* producing extra tasks amortizes the uncertainty of progress and
2154		* diffusion assumptions.
2155		*
2156	<	* So, users will want to use values larger, but not much larger
2156	>	* So, users will want to use values larger (but not much larger)
2157		* than 1 to both smooth over transient shortages and hedge
2158		* against uneven progress; as traded off against the cost of
2159		* extra task overhead. We leave the user to pick a threshold
#	Line 2230 \| Line 2177 \| public class ForkJoinPool extends Abstra
2177		static int getSurplusQueuedTaskCount() {
2178		Thread t; ForkJoinWorkerThread wt; ForkJoinPool pool; WorkQueue q;
2179		if (((t = Thread.currentThread()) instanceof ForkJoinWorkerThread)) {
2180	<	int p = (pool = (wt = (ForkJoinWorkerThread)t).pool).config & SMASK;
2180	>	int p = (pool = (wt = (ForkJoinWorkerThread)t).pool).parallelism;
2181		int n = (q = wt.workQueue).top - q.base;
2182		int a = (int)(pool.ctl >> AC_SHIFT) + p;
2183		return n - (a > (p >>>= 1) ? 0 :
#	Line 2259 \| Line 2206 \| public class ForkJoinPool extends Abstra
2206		* @return true if now terminating or terminated
2207		*/
2208		private boolean tryTerminate(boolean now, boolean enable) {
2209	<	if (this == commonPool) // cannot shut down
2209	>	int ps;
2210	>	if (this == common) // cannot shut down
2211		return false;
2212	+	if ((ps = plock) >= 0) { // enable by setting plock
2213	+	if (!enable)
2214	+	return false;
2215	+	if ((ps & PL_LOCK) != 0 \|\|
2216	+	!U.compareAndSwapInt(this, PLOCK, ps, ps += PL_LOCK))
2217	+	ps = acquirePlock();
2218	+	int nps = ((ps + PL_LOCK) & ~SHUTDOWN) \| SHUTDOWN;
2219	+	if (!U.compareAndSwapInt(this, PLOCK, ps, nps))
2220	+	releasePlock(nps);
2221	+	}
2222		for (long c;;) {
2223	<	if (((c = ctl) & STOP_BIT) != 0) { // already terminating
2224	<	if ((short)(c >>> TC_SHIFT) == -(config & SMASK)) {
2223	>	if (((c = ctl) & STOP_BIT) != 0) { // already terminating
2224	>	if ((short)(c >>> TC_SHIFT) + parallelism <= 0) {
2225		synchronized (this) {
2226	<	notifyAll(); // signal when 0 workers
2226	>	notifyAll(); // signal when 0 workers
2227		}
2228		}
2229		return true;
2230		}
2231	<	if (plock >= 0) { // not yet enabled
2232	<	int ps;
2233	<	if (!enable)
2231	>	if (!now) { // check if idle & no tasks
2232	>	WorkQueue[] ws; WorkQueue w;
2233	>	if ((int)(c >> AC_SHIFT) + parallelism > 0)
2234		return false;
2235	<	if (((ps = plock) & PL_LOCK) != 0 \|\|
2236	<	!U.compareAndSwapInt(this, PLOCK, ps, ps += PL_LOCK))
2237	<	ps = acquirePlock();
2238	<	if (!U.compareAndSwapInt(this, PLOCK, ps, SHUTDOWN))
2239	<	releasePlock(SHUTDOWN);
2240	<	}
2283	<	if (!now) { // check if idle & no tasks
2284	<	if ((int)(c >> AC_SHIFT) != -(config & SMASK) \|\|
2285	<	hasQueuedSubmissions())
2286	<	return false;
2287	<	// Check for unqueued inactive workers. One pass suffices.
2288	<	WorkQueue[] ws = workQueues; WorkQueue w;
2289	<	if (ws != null) {
2290	<	for (int i = 1; i < ws.length; i += 2) {
2291	<	if ((w = ws[i]) != null && w.eventCount >= 0)
2235	>	if ((ws = workQueues) != null) {
2236	>	for (int i = 0; i < ws.length; ++i) {
2237	>	if ((w = ws[i]) != null &&
2238	>	(!w.isEmpty() \|\|
2239	>	((i & 1) != 0 && w.eventCount >= 0))) {
2240	>	signalWork(ws, w);
2241		return false;
2242	+	}
2243		}
2244		}
2245		}
2246		if (U.compareAndSwapLong(this, CTL, c, c \| STOP_BIT)) {
2247		for (int pass = 0; pass < 3; ++pass) {
2248	<	WorkQueue[] ws = workQueues;
2249	<	if (ws != null) {
2300	<	WorkQueue w; Thread wt;
2248	>	WorkQueue[] ws; WorkQueue w; Thread wt;
2249	>	if ((ws = workQueues) != null) {
2250		int n = ws.length;
2251		for (int i = 0; i < n; ++i) {
2252		if ((w = ws[i]) != null) {
#	Line 2308 \| Line 2257 \| public class ForkJoinPool extends Abstra
2257		if (!wt.isInterrupted()) {
2258		try {
2259		wt.interrupt();
2260	<	} catch (SecurityException ignore) {
2260	>	} catch (Throwable ignore) {
2261		}
2262		}
2263		U.unpark(wt);
#	Line 2319 \| Line 2268 \| public class ForkJoinPool extends Abstra
2268		// Wake up workers parked on event queue
2269		int i, e; long cc; Thread p;
2270		while ((e = (int)(cc = ctl) & E_MASK) != 0 &&
2271	<	(i = e & SMASK) < n &&
2271	>	(i = e & SMASK) < n && i >= 0 &&
2272		(w = ws[i]) != null) {
2273		long nc = ((long)(w.nextWait & E_MASK) \|
2274		((cc + AC_UNIT) & AC_MASK) \|
#	Line 2345 \| Line 2294 \| public class ForkJoinPool extends Abstra
2294		* least one task.
2295		*/
2296		static WorkQueue commonSubmitterQueue() {
2297	<	ForkJoinPool p; WorkQueue[] ws; int m; Submitter z;
2297	>	Submitter z; ForkJoinPool p; WorkQueue[] ws; int m, r;
2298		return ((z = submitters.get()) != null &&
2299	<	(p = commonPool) != null &&
2299	>	(p = common) != null &&
2300		(ws = p.workQueues) != null &&
2301		(m = ws.length - 1) >= 0) ?
2302		ws[m & z.seed & SQMASK] : null;
#	Line 2356 \| Line 2305 \| public class ForkJoinPool extends Abstra
2305		/**
2306		* Tries to pop the given task from submitter's queue in common pool.
2307		*/
2308	<	static boolean tryExternalUnpush(ForkJoinTask<?> t) {
2309	<	ForkJoinPool p; WorkQueue[] ws; WorkQueue q; Submitter z;
2310	<	ForkJoinTask<?>[] a; int m, s;
2311	<	if (t != null &&
2312	<	(z = submitters.get()) != null &&
2313	<	(p = commonPool) != null &&
2314	<	(ws = p.workQueues) != null &&
2315	<	(m = ws.length - 1) >= 0 &&
2316	<	(q = ws[m & z.seed & SQMASK]) != null &&
2368	<	(s = q.top) != q.base &&
2369	<	(a = q.array) != null) {
2308	>	final boolean tryExternalUnpush(ForkJoinTask<?> task) {
2309	>	WorkQueue joiner; ForkJoinTask<?>[] a; int m, s;
2310	>	Submitter z = submitters.get();
2311	>	WorkQueue[] ws = workQueues;
2312	>	boolean popped = false;
2313	>	if (z != null && ws != null && (m = ws.length - 1) >= 0 &&
2314	>	(joiner = ws[z.seed & m & SQMASK]) != null &&
2315	>	joiner.base != (s = joiner.top) &&
2316	>	(a = joiner.array) != null) {
2317		long j = (((a.length - 1) & (s - 1)) << ASHIFT) + ABASE;
2318	<	if (U.getObject(a, j) == t &&
2319	<	U.compareAndSwapInt(q, QLOCK, 0, 1)) {
2320	<	if (q.array == a && q.top == s && // recheck
2321	<	U.compareAndSwapObject(a, j, t, null)) {
2322	<	q.top = s - 1;
2323	<	q.qlock = 0;
2377	<	return true;
2318	>	if (U.getObject(a, j) == task &&
2319	>	U.compareAndSwapInt(joiner, QLOCK, 0, 1)) {
2320	>	if (joiner.top == s && joiner.array == a &&
2321	>	U.compareAndSwapObject(a, j, task, null)) {
2322	>	joiner.top = s - 1;
2323	>	popped = true;
2324		}
2325	<	q.qlock = 0;
2325	>	joiner.qlock = 0;
2326		}
2327		}
2328	<	return false;
2328	>	return popped;
2329		}
2330
2331	<	/**
2332	<	* Tries to pop and run local tasks within the same computation
2333	<	* as the given root. On failure, tries to help complete from
2334	<	* other queues via helpComplete.
2335	<	*/
2336	<	private void externalHelpComplete(WorkQueue q, ForkJoinTask<?> root) {
2337	<	ForkJoinTask<?>[] a; int m;
2338	<	if (q != null && (a = q.array) != null && (m = (a.length - 1)) >= 0 &&
2339	<	root != null && root.status >= 0) {
2340	<	for (;;) {
2341	<	int s, u; Object o; CountedCompleter<?> task = null;
2342	<	if ((s = q.top) - q.base > 0) {
2343	<	long j = ((m & (s - 1)) << ASHIFT) + ABASE;
2398	<	if ((o = U.getObject(a, j)) != null &&
2399	<	(o instanceof CountedCompleter)) {
2400	<	CountedCompleter<?> t = (CountedCompleter<?>)o, r = t;
2401	<	do {
2402	<	if (r == root) {
2403	<	if (U.compareAndSwapInt(q, QLOCK, 0, 1)) {
2404	<	if (q.array == a && q.top == s &&
2405	<	U.compareAndSwapObject(a, j, t, null)) {
2406	<	q.top = s - 1;
2407	<	task = t;
2408	<	}
2409	<	q.qlock = 0;
2410	<	}
2411	<	break;
2412	<	}
2413	<	} while ((r = r.completer) != null);
2414	<	}
2415	<	}
2416	<	if (task != null)
2417	<	task.doExec();
2418	<	if (root.status < 0 \|\|
2419	<	(u = (int)(ctl >>> 32)) >= 0 \|\| (u >> UAC_SHIFT) >= 0)
2331	>	final int externalHelpComplete(CountedCompleter<?> task) {
2332	>	WorkQueue joiner; int m, j;
2333	>	Submitter z = submitters.get();
2334	>	WorkQueue[] ws = workQueues;
2335	>	int s = 0;
2336	>	if (z != null && ws != null && (m = ws.length - 1) >= 0 &&
2337	>	(joiner = ws[(j = z.seed) & m & SQMASK]) != null && task != null) {
2338	>	int scans = m + m + 1;
2339	>	long c = 0L; // for stability check
2340	>	j \|= 1; // poll odd queues
2341	>	for (int k = scans; ; j += 2) {
2342	>	WorkQueue q;
2343	>	if ((s = task.status) < 0)
2344		break;
2345	<	if (task == null) {
2346	<	helpSignal(root, q.poolIndex);
2347	<	if (root.status >= 0)
2424	<	helpComplete(root, SHARED_QUEUE);
2345	>	else if (joiner.externalPopAndExecCC(task))
2346	>	k = scans;
2347	>	else if ((s = task.status) < 0)
2348		break;
2349	+	else if ((q = ws[j & m]) != null && q.pollAndExecCC(task))
2350	+	k = scans;
2351	+	else if (--k < 0) {
2352	+	if (c == (c = ctl))
2353	+	break;
2354	+	k = scans;
2355		}
2356		}
2357		}
2358	<	}
2430	<
2431	<	/**
2432	<	* Tries to help execute or signal availability of the given task
2433	<	* from submitter's queue in common pool.
2434	<	*/
2435	<	static void externalHelpJoin(ForkJoinTask<?> t) {
2436	<	// Some hard-to-avoid overlap with tryExternalUnpush
2437	<	ForkJoinPool p; WorkQueue[] ws; WorkQueue q, w; Submitter z;
2438	<	ForkJoinTask<?>[] a; int m, s, n;
2439	<	if (t != null &&
2440	<	(z = submitters.get()) != null &&
2441	<	(p = commonPool) != null &&
2442	<	(ws = p.workQueues) != null &&
2443	<	(m = ws.length - 1) >= 0 &&
2444	<	(q = ws[m & z.seed & SQMASK]) != null &&
2445	<	(a = q.array) != null) {
2446	<	int am = a.length - 1;
2447	<	if ((s = q.top) != q.base) {
2448	<	long j = ((am & (s - 1)) << ASHIFT) + ABASE;
2449	<	if (U.getObject(a, j) == t &&
2450	<	U.compareAndSwapInt(q, QLOCK, 0, 1)) {
2451	<	if (q.array == a && q.top == s &&
2452	<	U.compareAndSwapObject(a, j, t, null)) {
2453	<	q.top = s - 1;
2454	<	q.qlock = 0;
2455	<	t.doExec();
2456	<	}
2457	<	else
2458	<	q.qlock = 0;
2459	<	}
2460	<	}
2461	<	if (t.status >= 0) {
2462	<	if (t instanceof CountedCompleter)
2463	<	p.externalHelpComplete(q, t);
2464	<	else
2465	<	p.helpSignal(t, q.poolIndex);
2466	<	}
2467	<	}
2468	<	}
2469	<
2470	<	/**
2471	<	* Restricted version of helpQuiescePool for external callers
2472	<	*/
2473	<	static void externalHelpQuiescePool() {
2474	<	ForkJoinPool p; ForkJoinTask<?> t; WorkQueue q; int b;
2475	<	if ((p = commonPool) != null &&
2476	<	(q = p.findNonEmptyStealQueue(1)) != null &&
2477	<	(b = q.base) - q.top < 0 &&
2478	<	(t = q.pollAt(b)) != null)
2479	<	t.doExec();
2358	>	return s;
2359		}
2360
2361		// Exported methods
#	Line 2495 \| Line 2374 \| public class ForkJoinPool extends Abstra
2374		* java.lang.RuntimePermission}{@code ("modifyThread")}
2375		*/
2376		public ForkJoinPool() {
2377	<	this(Runtime.getRuntime().availableProcessors(),
2377	>	this(Math.min(MAX_CAP, Runtime.getRuntime().availableProcessors()),
2378		defaultForkJoinWorkerThreadFactory, null, false);
2379		}
2380
#	Line 2543 \| Line 2422 \| public class ForkJoinPool extends Abstra
2422		*/
2423		public ForkJoinPool(int parallelism,
2424		ForkJoinWorkerThreadFactory factory,
2425	<	Thread.UncaughtExceptionHandler handler,
2425	>	UncaughtExceptionHandler handler,
2426		boolean asyncMode) {
2427	+	this(checkParallelism(parallelism),
2428	+	checkFactory(factory),
2429	+	handler,
2430	+	(asyncMode ? FIFO_QUEUE : LIFO_QUEUE),
2431	+	"ForkJoinPool-" + nextPoolId() + "-worker-");
2432		checkPermission();
2433	<	if (factory == null)
2434	<	throw new NullPointerException();
2433	>	}
2434	>
2435	>	private static int checkParallelism(int parallelism) {
2436		if (parallelism <= 0 \|\| parallelism > MAX_CAP)
2437		throw new IllegalArgumentException();
2438	<	this.factory = factory;
2439	<	this.ueh = handler;
2440	<	this.config = parallelism \| (asyncMode ? (FIFO_QUEUE << 16) : 0);
2441	<	long np = (long)(-parallelism); // offset ctl counts
2442	<	this.ctl = ((np << AC_SHIFT) & AC_MASK) \| ((np << TC_SHIFT) & TC_MASK);
2443	<	int pn = nextPoolId();
2444	<	StringBuilder sb = new StringBuilder("ForkJoinPool-");
2445	<	sb.append(Integer.toString(pn));
2561	<	sb.append("-worker-");
2562	<	this.workerNamePrefix = sb.toString();
2438	>	return parallelism;
2439	>	}
2440	>
2441	>	private static ForkJoinWorkerThreadFactory checkFactory
2442	>	(ForkJoinWorkerThreadFactory factory) {
2443	>	if (factory == null)
2444	>	throw new NullPointerException();
2445	>	return factory;
2446		}
2447
2448		/**
2449	<	* Constructor for common pool, suitable only for static initialization.
2450	<	* Basically the same as above, but uses smallest possible initial footprint.
2451	<	*/
2452	<	ForkJoinPool(int parallelism, long ctl,
2453	<	ForkJoinWorkerThreadFactory factory,
2454	<	Thread.UncaughtExceptionHandler handler) {
2455	<	this.config = parallelism;
2456	<	this.ctl = ctl;
2449	>	* Creates a {@code ForkJoinPool} with the given parameters, without
2450	>	* any security checks or parameter validation. Invoked directly by
2451	>	* makeCommonPool.
2452	>	*/
2453	>	private ForkJoinPool(int parallelism,
2454	>	ForkJoinWorkerThreadFactory factory,
2455	>	UncaughtExceptionHandler handler,
2456	>	int mode,
2457	>	String workerNamePrefix) {
2458	>	this.workerNamePrefix = workerNamePrefix;
2459		this.factory = factory;
2460		this.ueh = handler;
2461	<	this.workerNamePrefix = "ForkJoinPool.commonPool-worker-";
2461	>	this.mode = (short)mode;
2462	>	this.parallelism = (short)parallelism;
2463	>	long np = (long)(-parallelism); // offset ctl counts
2464	>	this.ctl = ((np << AC_SHIFT) & AC_MASK) \| ((np << TC_SHIFT) & TC_MASK);
2465		}
2466
2467		/**
2468		* Returns the common pool instance. This pool is statically
2469	<	* constructed; its run state is unaffected by attempts to
2470	<	* {@link #shutdown} or {@link #shutdownNow}.
2469	>	* constructed; its run state is unaffected by attempts to {@link
2470	>	* #shutdown} or {@link #shutdownNow}. However this pool and any
2471	>	* ongoing processing are automatically terminated upon program
2472	>	* {@link System#exit}. Any program that relies on asynchronous
2473	>	* task processing to complete before program termination should
2474	>	* invoke {@code commonPool().}{@link #awaitQuiescence awaitQuiescence},
2475	>	* before exit.
2476		*
2477		* @return the common pool instance
2478	+	* @since 1.8
2479		*/
2480		public static ForkJoinPool commonPool() {
2481	<	// assert commonPool != null : "static init error";
2482	<	return commonPool;
2481	>	// assert common != null : "static init error";
2482	>	return common;
2483		}
2484
2485		// Execution methods
#	Line 2641 \| Line 2535 \| public class ForkJoinPool extends Abstra
2535		if (task instanceof ForkJoinTask<?>) // avoid re-wrap
2536		job = (ForkJoinTask<?>) task;
2537		else
2538	<	job = new ForkJoinTask.AdaptedRunnableAction(task);
2538	>	job = new ForkJoinTask.RunnableExecuteAction(task);
2539		externalPush(job);
2540		}
2541
#	Line 2708 \| Line 2602 \| public class ForkJoinPool extends Abstra
2602		// In previous versions of this class, this method constructed
2603		// a task to run ForkJoinTask.invokeAll, but now external
2604		// invocation of multiple tasks is at least as efficient.
2605	<	List<ForkJoinTask<T>> fs = new ArrayList<ForkJoinTask<T>>(tasks.size());
2712	<	// Workaround needed because method wasn't declared with
2713	<	// wildcards in return type but should have been.
2714	<	@SuppressWarnings({"unchecked", "rawtypes"})
2715	<	List<Future<T>> futures = (List<Future<T>>) (List) fs;
2605	>	ArrayList<Future<T>> futures = new ArrayList<Future<T>>(tasks.size());
2606
2607		boolean done = false;
2608		try {
2609		for (Callable<T> t : tasks) {
2610		ForkJoinTask<T> f = new ForkJoinTask.AdaptedCallable<T>(t);
2611	+	futures.add(f);
2612		externalPush(f);
2722	–	fs.add(f);
2613		}
2614	<	for (ForkJoinTask<T> f : fs)
2615	<	f.quietlyJoin();
2614	>	for (int i = 0, size = futures.size(); i < size; i++)
2615	>	((ForkJoinTask<?>)futures.get(i)).quietlyJoin();
2616		done = true;
2617		return futures;
2618		} finally {
2619		if (!done)
2620	<	for (ForkJoinTask<T> f : fs)
2621	<	f.cancel(false);
2620	>	for (int i = 0, size = futures.size(); i < size; i++)
2621	>	futures.get(i).cancel(false);
2622		}
2623		}
2624
#	Line 2747 \| Line 2637 \| public class ForkJoinPool extends Abstra
2637		*
2638		* @return the handler, or {@code null} if none
2639		*/
2640	<	public Thread.UncaughtExceptionHandler getUncaughtExceptionHandler() {
2640	>	public UncaughtExceptionHandler getUncaughtExceptionHandler() {
2641		return ueh;
2642		}
2643
#	Line 2757 \| Line 2647 \| public class ForkJoinPool extends Abstra
2647		* @return the targeted parallelism level of this pool
2648		*/
2649		public int getParallelism() {
2650	<	return config & SMASK;
2650	>	int par;
2651	>	return ((par = parallelism) > 0) ? par : 1;
2652		}
2653
2654		/**
2655		* Returns the targeted parallelism level of the common pool.
2656		*
2657		* @return the targeted parallelism level of the common pool
2658	+	* @since 1.8
2659		*/
2660		public static int getCommonPoolParallelism() {
2661	<	return commonPoolParallelism;
2661	>	return commonParallelism;
2662		}
2663
2664		/**
#	Line 2778 \| Line 2670 \| public class ForkJoinPool extends Abstra
2670		* @return the number of worker threads
2671		*/
2672		public int getPoolSize() {
2673	<	return (config & SMASK) + (short)(ctl >>> TC_SHIFT);
2673	>	return parallelism + (short)(ctl >>> TC_SHIFT);
2674		}
2675
2676		/**
#	Line 2788 \| Line 2680 \| public class ForkJoinPool extends Abstra
2680		* @return {@code true} if this pool uses async mode
2681		*/
2682		public boolean getAsyncMode() {
2683	<	return (config >>> 16) == FIFO_QUEUE;
2683	>	return mode == FIFO_QUEUE;
2684		}
2685
2686		/**
#	Line 2819 \| Line 2711 \| public class ForkJoinPool extends Abstra
2711		* @return the number of active threads
2712		*/
2713		public int getActiveThreadCount() {
2714	<	int r = (config & SMASK) + (int)(ctl >> AC_SHIFT);
2714	>	int r = parallelism + (int)(ctl >> AC_SHIFT);
2715		return (r <= 0) ? 0 : r; // suppress momentarily negative values
2716		}
2717
#	Line 2835 \| Line 2727 \| public class ForkJoinPool extends Abstra
2727		* @return {@code true} if all threads are currently idle
2728		*/
2729		public boolean isQuiescent() {
2730	<	return (int)(ctl >> AC_SHIFT) + (config & SMASK) == 0;
2730	>	return parallelism + (int)(ctl >> AC_SHIFT) <= 0;
2731		}
2732
2733		/**
#	Line 2998 \| Line 2890 \| public class ForkJoinPool extends Abstra
2890		}
2891		}
2892		}
2893	<	int pc = (config & SMASK);
2893	>	int pc = parallelism;
2894		int tc = pc + (short)(c >>> TC_SHIFT);
2895		int ac = pc + (int)(c >> AC_SHIFT);
2896		if (ac < 0) // ignore transient negative
#	Line 3024 \| Line 2916 \| public class ForkJoinPool extends Abstra
2916		* Possibly initiates an orderly shutdown in which previously
2917		* submitted tasks are executed, but no new tasks will be
2918		* accepted. Invocation has no effect on execution state if this
2919	<	* is the {@link #commonPool}, and no additional effect if
2919	>	* is the {@link #commonPool()}, and no additional effect if
2920		* already shut down. Tasks that are in the process of being
2921		* submitted concurrently during the course of this method may or
2922		* may not be rejected.
#	Line 3042 \| Line 2934 \| public class ForkJoinPool extends Abstra
2934		/**
2935		* Possibly attempts to cancel and/or stop all tasks, and reject
2936		* all subsequently submitted tasks. Invocation has no effect on
2937	<	* execution state if this is the {@link #commonPool}, and no
2937	>	* execution state if this is the {@link #commonPool()}, and no
2938		* additional effect if already shut down. Otherwise, tasks that
2939		* are in the process of being submitted or executed concurrently
2940		* during the course of this method may or may not be
#	Line 3071 \| Line 2963 \| public class ForkJoinPool extends Abstra
2963		public boolean isTerminated() {
2964		long c = ctl;
2965		return ((c & STOP_BIT) != 0L &&
2966	<	(short)(c >>> TC_SHIFT) == -(config & SMASK));
2966	>	(short)(c >>> TC_SHIFT) + parallelism <= 0);
2967		}
2968
2969		/**
#	Line 3090 \| Line 2982 \| public class ForkJoinPool extends Abstra
2982		public boolean isTerminating() {
2983		long c = ctl;
2984		return ((c & STOP_BIT) != 0L &&
2985	<	(short)(c >>> TC_SHIFT) != -(config & SMASK));
2985	>	(short)(c >>> TC_SHIFT) + parallelism > 0);
2986		}
2987
2988		/**
#	Line 3105 \| Line 2997 \| public class ForkJoinPool extends Abstra
2997		/**
2998		* Blocks until all tasks have completed execution after a
2999		* shutdown request, or the timeout occurs, or the current thread
3000	<	* is interrupted, whichever happens first. Note that the {@link
3001	<	* #commonPool()} never terminates until program shutdown so
3002	<	* this method will always time out.
3000	>	* is interrupted, whichever happens first. Because the {@link
3001	>	* #commonPool()} never terminates until program shutdown, when
3002	>	* applied to the common pool, this method is equivalent to {@link
3003	>	* #awaitQuiescence(long, TimeUnit)} but always returns {@code false}.
3004		*
3005		* @param timeout the maximum time to wait
3006		* @param unit the time unit of the timeout argument
#	Line 3117 \| Line 3010 \| public class ForkJoinPool extends Abstra
3010		*/
3011		public boolean awaitTermination(long timeout, TimeUnit unit)
3012		throws InterruptedException {
3013	+	if (Thread.interrupted())
3014	+	throw new InterruptedException();
3015	+	if (this == common) {
3016	+	awaitQuiescence(timeout, unit);
3017	+	return false;
3018	+	}
3019		long nanos = unit.toNanos(timeout);
3020		if (isTerminated())
3021		return true;
3022	<	long startTime = System.nanoTime();
3023	<	boolean terminated = false;
3022	>	if (nanos <= 0L)
3023	>	return false;
3024	>	long deadline = System.nanoTime() + nanos;
3025		synchronized (this) {
3026	<	for (long waitTime = nanos, millis = 0L;;) {
3027	<	if (terminated = isTerminated() \|\|
3028	<	waitTime <= 0L \|\|
3029	<	(millis = unit.toMillis(waitTime)) <= 0L)
3026	>	for (;;) {
3027	>	if (isTerminated())
3028	>	return true;
3029	>	if (nanos <= 0L)
3030	>	return false;
3031	>	long millis = TimeUnit.NANOSECONDS.toMillis(nanos);
3032	>	wait(millis > 0L ? millis : 1L);
3033	>	nanos = deadline - System.nanoTime();
3034	>	}
3035	>	}
3036	>	}
3037	>
3038	>	/**
3039	>	* If called by a ForkJoinTask operating in this pool, equivalent
3040	>	* in effect to {@link ForkJoinTask#helpQuiesce}. Otherwise,
3041	>	* waits and/or attempts to assist performing tasks until this
3042	>	* pool {@link #isQuiescent} or the indicated timeout elapses.
3043	>	*
3044	>	* @param timeout the maximum time to wait
3045	>	* @param unit the time unit of the timeout argument
3046	>	* @return {@code true} if quiescent; {@code false} if the
3047	>	* timeout elapsed.
3048	>	*/
3049	>	public boolean awaitQuiescence(long timeout, TimeUnit unit) {
3050	>	long nanos = unit.toNanos(timeout);
3051	>	ForkJoinWorkerThread wt;
3052	>	Thread thread = Thread.currentThread();
3053	>	if ((thread instanceof ForkJoinWorkerThread) &&
3054	>	(wt = (ForkJoinWorkerThread)thread).pool == this) {
3055	>	helpQuiescePool(wt.workQueue);
3056	>	return true;
3057	>	}
3058	>	long startTime = System.nanoTime();
3059	>	WorkQueue[] ws;
3060	>	int r = 0, m;
3061	>	boolean found = true;
3062	>	while (!isQuiescent() && (ws = workQueues) != null &&
3063	>	(m = ws.length - 1) >= 0) {
3064	>	if (!found) {
3065	>	if ((System.nanoTime() - startTime) > nanos)
3066	>	return false;
3067	>	Thread.yield(); // cannot block
3068	>	}
3069	>	found = false;
3070	>	for (int j = (m + 1) << 2; j >= 0; --j) {
3071	>	ForkJoinTask<?> t; WorkQueue q; int b;
3072	>	if ((q = ws[r++ & m]) != null && (b = q.base) - q.top < 0) {
3073	>	found = true;
3074	>	if ((t = q.pollAt(b)) != null)
3075	>	t.doExec();
3076		break;
3077	<	wait(millis);
3132	<	waitTime = nanos - (System.nanoTime() - startTime);
3077	>	}
3078		}
3079		}
3080	<	return terminated;
3080	>	return true;
3081	>	}
3082	>
3083	>	/**
3084	>	* Waits and/or attempts to assist performing tasks indefinitely
3085	>	* until the {@link #commonPool()} {@link #isQuiescent}.
3086	>	*/
3087	>	static void quiesceCommonPool() {
3088	>	common.awaitQuiescence(Long.MAX_VALUE, TimeUnit.NANOSECONDS);
3089		}
3090
3091		/**
#	Line 3144 \| Line 3097 \| public class ForkJoinPool extends Abstra
3097		* not necessary. Method {@code block} blocks the current thread
3098		* if necessary (perhaps internally invoking {@code isReleasable}
3099		* before actually blocking). These actions are performed by any
3100	<	* thread invoking {@link ForkJoinPool#managedBlock}. The
3101	<	* unusual methods in this API accommodate synchronizers that may,
3102	<	* but don't usually, block for long periods. Similarly, they
3100	>	* thread invoking {@link ForkJoinPool#managedBlock(ManagedBlocker)}.
3101	>	* The unusual methods in this API accommodate synchronizers that
3102	>	* may, but don't usually, block for long periods. Similarly, they
3103		* allow more efficient internal handling of cases in which
3104		* additional workers may be, but usually are not, needed to
3105		* ensure sufficient parallelism. Toward this end,
#	Line 3204 \| Line 3157 \| public class ForkJoinPool extends Abstra
3157
3158		/**
3159		* Returns {@code true} if blocking is unnecessary.
3160	+	* @return {@code true} if blocking is unnecessary
3161		*/
3162		boolean isReleasable();
3163		}
#	Line 3233 \| Line 3187 \| public class ForkJoinPool extends Abstra
3187		Thread t = Thread.currentThread();
3188		if (t instanceof ForkJoinWorkerThread) {
3189		ForkJoinPool p = ((ForkJoinWorkerThread)t).pool;
3190	<	while (!blocker.isReleasable()) { // variant of helpSignal
3191	<	WorkQueue[] ws; WorkQueue q; int m, u;
3238	<	if ((ws = p.workQueues) != null && (m = ws.length - 1) >= 0) {
3239	<	for (int i = 0; i <= m; ++i) {
3240	<	if (blocker.isReleasable())
3241	<	return;
3242	<	if ((q = ws[i]) != null && q.base - q.top < 0) {
3243	<	p.signalWork(q);
3244	<	if ((u = (int)(p.ctl >>> 32)) >= 0 \|\|
3245	<	(u >> UAC_SHIFT) >= 0)
3246	<	break;
3247	<	}
3248	<	}
3249	<	}
3250	<	if (p.tryCompensate()) {
3190	>	while (!blocker.isReleasable()) {
3191	>	if (p.tryCompensate(p.ctl)) {
3192		try {
3193		do {} while (!blocker.isReleasable() &&
3194		!blocker.block());
#	Line 3285 \| Line 3226 \| public class ForkJoinPool extends Abstra
3226		private static final long STEALCOUNT;
3227		private static final long PLOCK;
3228		private static final long INDEXSEED;
3229	+	private static final long QBASE;
3230		private static final long QLOCK;
3231
3232		static {
3233	<	int s; // initialize field offsets for CAS etc
3233	>	// initialize field offsets for CAS etc
3234		try {
3235		U = getUnsafe();
3236		Class<?> k = ForkJoinPool.class;
#	Line 3304 \| Line 3246 \| public class ForkJoinPool extends Abstra
3246		PARKBLOCKER = U.objectFieldOffset
3247		(tk.getDeclaredField("parkBlocker"));
3248		Class<?> wk = WorkQueue.class;
3249	+	QBASE = U.objectFieldOffset
3250	+	(wk.getDeclaredField("base"));
3251		QLOCK = U.objectFieldOffset
3252		(wk.getDeclaredField("qlock"));
3253		Class<?> ak = ForkJoinTask[].class;
3254		ABASE = U.arrayBaseOffset(ak);
3255	<	s = U.arrayIndexScale(ak);
3256	<	ASHIFT = 31 - Integer.numberOfLeadingZeros(s);
3255	>	int scale = U.arrayIndexScale(ak);
3256	>	if ((scale & (scale - 1)) != 0)
3257	>	throw new Error("data type scale not a power of two");
3258	>	ASHIFT = 31 - Integer.numberOfLeadingZeros(scale);
3259		} catch (Exception e) {
3260		throw new Error(e);
3261		}
3316	–	if ((s & (s-1)) != 0)
3317	–	throw new Error("data type scale not a power of two");
3262
3263		submitters = new ThreadLocal<Submitter>();
3264	<	ForkJoinWorkerThreadFactory fac = defaultForkJoinWorkerThreadFactory =
3264	>	defaultForkJoinWorkerThreadFactory =
3265		new DefaultForkJoinWorkerThreadFactory();
3266		modifyThreadPermission = new RuntimePermission("modifyThread");
3267
3268	<	/*
3269	<	* Establish common pool parameters. For extra caution,
3270	<	* computations to set up common pool state are here; the
3271	<	* constructor just assigns these values to fields.
3272	<	*/
3268	>	common = java.security.AccessController.doPrivileged
3269	>	(new java.security.PrivilegedAction<ForkJoinPool>() {
3270	>	public ForkJoinPool run() { return makeCommonPool(); }});
3271	>	int par = common.parallelism; // report 1 even if threads disabled
3272	>	commonParallelism = par > 0 ? par : 1;
3273	>	}
3274
3275	<	int par = 0;
3276	<	Thread.UncaughtExceptionHandler handler = null;
3277	<	try { // TBD: limit or report ignored exceptions?
3275	>	/**
3276	>	* Creates and returns the common pool, respecting user settings
3277	>	* specified via system properties.
3278	>	*/
3279	>	private static ForkJoinPool makeCommonPool() {
3280	>	int parallelism = -1;
3281	>	ForkJoinWorkerThreadFactory factory
3282	>	= defaultForkJoinWorkerThreadFactory;
3283	>	UncaughtExceptionHandler handler = null;
3284	>	try { // ignore exceptions in accessing/parsing properties
3285		String pp = System.getProperty
3286		("java.util.concurrent.ForkJoinPool.common.parallelism");
3335	–	String hp = System.getProperty
3336	–	("java.util.concurrent.ForkJoinPool.common.exceptionHandler");
3287		String fp = System.getProperty
3288		("java.util.concurrent.ForkJoinPool.common.threadFactory");
3289	+	String hp = System.getProperty
3290	+	("java.util.concurrent.ForkJoinPool.common.exceptionHandler");
3291	+	if (pp != null)
3292	+	parallelism = Integer.parseInt(pp);
3293		if (fp != null)
3294	<	fac = ((ForkJoinWorkerThreadFactory)ClassLoader.
3295	<	getSystemClassLoader().loadClass(fp).newInstance());
3294	>	factory = ((ForkJoinWorkerThreadFactory)ClassLoader.
3295	>	getSystemClassLoader().loadClass(fp).newInstance());
3296		if (hp != null)
3297	<	handler = ((Thread.UncaughtExceptionHandler)ClassLoader.
3297	>	handler = ((UncaughtExceptionHandler)ClassLoader.
3298		getSystemClassLoader().loadClass(hp).newInstance());
3345	–	if (pp != null)
3346	–	par = Integer.parseInt(pp);
3299		} catch (Exception ignore) {
3300		}
3301
3302	<	if (par <= 0)
3303	<	par = Runtime.getRuntime().availableProcessors();
3304	<	if (par > MAX_CAP)
3305	<	par = MAX_CAP;
3306	<	commonPoolParallelism = par;
3307	<	long np = (long)(-par); // precompute initial ctl value
3308	<	long ct = ((np << AC_SHIFT) & AC_MASK) \| ((np << TC_SHIFT) & TC_MASK);
3357	<
3358	<	commonPool = new ForkJoinPool(par, ct, fac, handler);
3302	>	if (parallelism < 0 && // default 1 less than #cores
3303	>	(parallelism = Runtime.getRuntime().availableProcessors() - 1) < 0)
3304	>	parallelism = 0;
3305	>	if (parallelism > MAX_CAP)
3306	>	parallelism = MAX_CAP;
3307	>	return new ForkJoinPool(parallelism, factory, handler, LIFO_QUEUE,
3308	>	"ForkJoinPool.commonPool-worker-");
3309		}
3310
3311		/**
#	Line 3368 \| Line 3318 \| public class ForkJoinPool extends Abstra
3318		private static sun.misc.Unsafe getUnsafe() {
3319		try {
3320		return sun.misc.Unsafe.getUnsafe();
3321	<	} catch (SecurityException se) {
3322	<	try {
3323	<	return java.security.AccessController.doPrivileged
3324	<	(new java.security
3325	<	.PrivilegedExceptionAction<sun.misc.Unsafe>() {
3326	<	public sun.misc.Unsafe run() throws Exception {
3327	<	java.lang.reflect.Field f = sun.misc
3328	<	.Unsafe.class.getDeclaredField("theUnsafe");
3329	<	f.setAccessible(true);
3330	<	return (sun.misc.Unsafe) f.get(null);
3331	<	}});
3332	<	} catch (java.security.PrivilegedActionException e) {
3333	<	throw new RuntimeException("Could not initialize intrinsics",
3334	<	e.getCause());
3335	<	}
3321	>	} catch (SecurityException tryReflectionInstead) {}
3322	>	try {
3323	>	return java.security.AccessController.doPrivileged
3324	>	(new java.security.PrivilegedExceptionAction<sun.misc.Unsafe>() {
3325	>	public sun.misc.Unsafe run() throws Exception {
3326	>	Class<sun.misc.Unsafe> k = sun.misc.Unsafe.class;
3327	>	for (java.lang.reflect.Field f : k.getDeclaredFields()) {
3328	>	f.setAccessible(true);
3329	>	Object x = f.get(null);
3330	>	if (k.isInstance(x))
3331	>	return k.cast(x);
3332	>	}
3333	>	throw new NoSuchFieldError("the Unsafe");
3334	>	}});
3335	>	} catch (java.security.PrivilegedActionException e) {
3336	>	throw new RuntimeException("Could not initialize intrinsics",
3337	>	e.getCause());
3338		}
3339		}
3388	–
3340		}

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing jsr166/src/jsr166e/ForkJoinPool.java (file contents): Revision 1.35 by dl, Mon Dec 17 16:32:47 2012 UTC vs. Revision 1.61 by jsr166, Sun Jul 14 19:55:05 2013 UTC

Diff Legend

Comparing jsr166/src/jsr166e/ForkJoinPool.java (file contents):
Revision 1.35 by dl, Mon Dec 17 16:32:47 2012 UTC vs.
Revision 1.61 by jsr166, Sun Jul 14 19:55:05 2013 UTC