ViewVC Help

View File | Revision Log | Show Annotations | Download File | Root Listing

root/jsr166/jsr166/src/jsr166y/Phaser.java

Comparing jsr166/src/jsr166y/Phaser.java (file contents):
Revision 1.6 by dl, Tue Oct 28 23:03:24 2008 UTC vs.
Revision 1.75 by dl, Wed Sep 21 12:30:39 2011 UTC

#	Line 1 | Line 1
1		/*
2		* Written by Doug Lea with assistance from members of JCP JSR-166
3		* Expert Group and released to the public domain, as explained at
4	<	* http://creativecommons.org/licenses/publicdomain
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5		*/
6
7		package jsr166y;
8	<	import java.util.concurrent.*;
9	<	import java.util.concurrent.atomic.*;
8	>
9	>	import java.util.concurrent.TimeUnit;
10	>	import java.util.concurrent.TimeoutException;
11	>	import java.util.concurrent.atomic.AtomicReference;
12		import java.util.concurrent.locks.LockSupport;
11	–	import sun.misc.Unsafe;
12	–	import java.lang.reflect.*;
13
14		/**
15	<	* A reusable synchronization barrier, similar in functionality to a
16	<	* {@link java.util.concurrent.CyclicBarrier} and {@link
17	<	* java.util.concurrent.CountDownLatch} but supporting more flexible
18	<	* usage.
15	>	* A reusable synchronization barrier, similar in functionality to
16	>	* {@link java.util.concurrent.CyclicBarrier CyclicBarrier} and
17	>	* {@link java.util.concurrent.CountDownLatch CountDownLatch}
18	>	* but supporting more flexible usage.
19	>	*
20	>	* <p> <b>Registration.</b> Unlike the case for other barriers, the
21	>	* number of parties <em>registered</em> to synchronize on a phaser
22	>	* may vary over time.  Tasks may be registered at any time (using
23	>	* methods {@link #register}, {@link #bulkRegister}, or forms of
24	>	* constructors establishing initial numbers of parties), and
25	>	* optionally deregistered upon any arrival (using {@link
26	>	* #arriveAndDeregister}).  As is the case with most basic
27	>	* synchronization constructs, registration and deregistration affect
28	>	* only internal counts; they do not establish any further internal
29	>	* bookkeeping, so tasks cannot query whether they are registered.
30	>	* (However, you can introduce such bookkeeping by subclassing this
31	>	* class.)
32	>	*
33	>	* <p> <b>Synchronization.</b> Like a {@code CyclicBarrier}, a {@code
34	>	* Phaser} may be repeatedly awaited.  Method {@link
35	>	* #arriveAndAwaitAdvance} has effect analogous to {@link
36	>	* java.util.concurrent.CyclicBarrier#await CyclicBarrier.await}. Each
37	>	* generation of a phaser has an associated phase number. The phase
38	>	* number starts at zero, and advances when all parties arrive at the
39	>	* phaser, wrapping around to zero after reaching {@code
40	>	* Integer.MAX_VALUE}. The use of phase numbers enables independent
41	>	* control of actions upon arrival at a phaser and upon awaiting
42	>	* others, via two kinds of methods that may be invoked by any
43	>	* registered party:
44		*
45		* <ul>
46		*
47	<	* <li> The number of parties synchronizing on a phaser may vary over
48	<	* time.  A task may register to be a party at any time, and may
49	<	* deregister upon arriving at the barrier.  As is the case with most
50	<	* basic synchronization constructs, registration and deregistration
51	<	* affect only internal counts; they do not establish any further
52	<	* internal bookkeeping, so tasks cannot query whether they are
53	<	* registered. (However, you can introduce such bookkeeping in by
54	<	* subclassing this class.)
55	<	*
56	<	* <li> Each generation has an associated phase value, starting at
57	<	* zero, and advancing when all parties reach the barrier (wrapping
58	<	* around to zero after reaching <tt>Integer.MAX_VALUE</tt>).
59	<	*
60	<	* <li> Like a CyclicBarrier, a Phaser may be repeatedly awaited.
61	<	* Method <tt>arriveAndAwaitAdvance</tt> has effect analogous to
62	<	* <tt>CyclicBarrier.await</tt>.  However, Phasers separate two
63	<	* aspects of coordination, that may also be invoked independently:
64	<	*
65	<	* <ul>
47	>	*   <li> <b>Arrival.</b> Methods {@link #arrive} and
48	>	*       {@link #arriveAndDeregister} record arrival.  These methods
49	>	*       do not block, but return an associated <em>arrival phase
50	>	*       number</em>; that is, the phase number of the phaser to which
51	>	*       the arrival applied. When the final party for a given phase
52	>	*       arrives, an optional action is performed and the phase
53	>	*       advances.  These actions are performed by the party
54	>	*       triggering a phase advance, and are arranged by overriding
55	>	*       method {@link #onAdvance(int, int)}, which also controls
56	>	*       termination. Overriding this method is similar to, but more
57	>	*       flexible than, providing a barrier action to a {@code
58	>	*       CyclicBarrier}.
59	>	*
60	>	*   <li> <b>Waiting.</b> Method {@link #awaitAdvance} requires an
61	>	*       argument indicating an arrival phase number, and returns when
62	>	*       the phaser advances to (or is already at) a different phase.
63	>	*       Unlike similar constructions using {@code CyclicBarrier},
64	>	*       method {@code awaitAdvance} continues to wait even if the
65	>	*       waiting thread is interrupted. Interruptible and timeout
66	>	*       versions are also available, but exceptions encountered while
67	>	*       tasks wait interruptibly or with timeout do not change the
68	>	*       state of the phaser. If necessary, you can perform any
69	>	*       associated recovery within handlers of those exceptions,
70	>	*       often after invoking {@code forceTermination}.  Phasers may
71	>	*       also be used by tasks executing in a {@link ForkJoinPool},
72	>	*       which will ensure sufficient parallelism to execute tasks
73	>	*       when others are blocked waiting for a phase to advance.
74		*
42	–	*   <li> Arriving at a barrier. Methods <tt>arrive</tt> and
43	–	*       <tt>arriveAndDeregister</tt> do not block, but return
44	–	*       the phase value current upon entry to the method.
45	–	*
46	–	*   <li> Awaiting others. Method <tt>awaitAdvance</tt> requires an
47	–	*       argument indicating the entry phase, and returns when the
48	–	*       barrier advances to a new phase.
75		* </ul>
76		*
77	<	*
78	<	* <li> Barrier actions, performed by the task triggering a phase
79	<	* advance while others may be waiting, are arranged by overriding
80	<	* method <tt>onAdvance</tt>, that also controls termination.
81	<	* Overriding this method may be used to similar but more flexible
82	<	* effect as providing a barrier action to a CyclicBarrier.
83	<	*
84	<	* <li> Phasers may enter a <em>termination</em> state in which all
85	<	* await actions immediately return, indicating (via a negative phase
86	<	* value) that execution is complete.  Termination is triggered by
87	<	* executing the overridable <tt>onAdvance</tt> method that is invoked
88	<	* each time the barrier is about to be tripped. When a Phaser is
89	<	* controlling an action with a fixed number of iterations, it is
90	<	* often convenient to override this method to cause termination when
91	<	* the current phase number reaches a threshold. Method
92	<	* <tt>forceTermination</tt> is also available to abruptly release
93	<	* waiting threads and allow them to terminate.
94	<	*
95	<	* <li> Phasers may be tiered to reduce contention. Phasers with large
96	<	* numbers of parties that would otherwise experience heavy
97	<	* synchronization contention costs may instead be arranged in trees.
98	<	* This will typically greatly increase throughput even though it
99	<	* incurs somewhat greater per-operation overhead.
100	<	*
101	<	* <li> By default, <tt>awaitAdvance</tt> continues to wait even if
102	<	* the waiting thread is interrupted. And unlike the case in
103	<	* CyclicBarriers, exceptions encountered while tasks wait
104	<	* interruptibly or with timeout do not change the state of the
105	<	* barrier. If necessary, you can perform any associated recovery
106	<	* within handlers of those exceptions, often after invoking
107	<	* <tt>forceTermination</tt>.
108	<	*
109	<	* </ul>
77	>	* <p> <b>Termination.</b> A phaser may enter a <em>termination</em>
78	>	* state, that may be checked using method {@link #isTerminated}. Upon
79	>	* termination, all synchronization methods immediately return without
80	>	* waiting for advance, as indicated by a negative return value.
81	>	* Similarly, attempts to register upon termination have no effect.
82	>	* Termination is triggered when an invocation of {@code onAdvance}
83	>	* returns {@code true}. The default implementation returns {@code
84	>	* true} if a deregistration has caused the number of registered
85	>	* parties to become zero.  As illustrated below, when phasers control
86	>	* actions with a fixed number of iterations, it is often convenient
87	>	* to override this method to cause termination when the current phase
88	>	* number reaches a threshold. Method {@link #forceTermination} is
89	>	* also available to abruptly release waiting threads and allow them
90	>	* to terminate.
91	>	*
92	>	* <p> <b>Tiering.</b> Phasers may be <em>tiered</em> (i.e.,
93	>	* constructed in tree structures) to reduce contention. Phasers with
94	>	* large numbers of parties that would otherwise experience heavy
95	>	* synchronization contention costs may instead be set up so that
96	>	* groups of sub-phasers share a common parent.  This may greatly
97	>	* increase throughput even though it incurs greater per-operation
98	>	* overhead.
99	>	*
100	>	* <p>In a tree of tiered phasers, registration and deregistration of
101	>	* child phasers with their parent are managed automatically.
102	>	* Whenever the number of registered parties of a child phaser becomes
103	>	* non-zero (as established in the {@link #Phaser(Phaser,int)}
104	>	* constructor, {@link #register}, or {@link #bulkRegister}), the
105	>	* child phaser is registered with its parent.  Whenever the number of
106	>	* registered parties becomes zero as the result of an invocation of
107	>	* {@link #arriveAndDeregister}, the child phaser is deregistered
108	>	* from its parent.
109	>	*
110	>	* <p><b>Monitoring.</b> While synchronization methods may be invoked
111	>	* only by registered parties, the current state of a phaser may be
112	>	* monitored by any caller.  At any given moment there are {@link
113	>	* #getRegisteredParties} parties in total, of which {@link
114	>	* #getArrivedParties} have arrived at the current phase ({@link
115	>	* #getPhase}).  When the remaining ({@link #getUnarrivedParties})
116	>	* parties arrive, the phase advances.  The values returned by these
117	>	* methods may reflect transient states and so are not in general
118	>	* useful for synchronization control.  Method {@link #toString}
119	>	* returns snapshots of these state queries in a form convenient for
120	>	* informal monitoring.
121		*
122		* <p><b>Sample usages:</b>
123		*
124	<	* <p>A Phaser may be used instead of a <tt>CountdownLatch</tt> to control
125	<	* a one-shot action serving a variable number of parties. The typical
126	<	* idiom is for the method setting this up to first register, then
127	<	* start the actions, then deregister, as in:
128	<	*
129	<	* <pre>
130	<	*  void runTasks(List&lt;Runnable&gt; list) {
131	<	*    final Phaser phaser = new Phaser(1); // "1" to register self
132	<	*    for (Runnable r : list) {
133	<	*      phaser.register();
134	<	*      new Thread() {
135	<	*        public void run() {
136	<	*          phaser.arriveAndAwaitAdvance(); // await all creation
137	<	*          r.run();
138	<	*          phaser.arriveAndDeregister();   // signal completion
139	<	*        }
140	<	*      }.start();
124	>	* <p>A {@code Phaser} may be used instead of a {@code CountDownLatch}
125	>	* to control a one-shot action serving a variable number of parties.
126	>	* The typical idiom is for the method setting this up to first
127	>	* register, then start the actions, then deregister, as in:
128	>	*
129	>	*  <pre> {@code
130	>	* void runTasks(List<Runnable> tasks) {
131	>	*   final Phaser phaser = new Phaser(1); // "1" to register self
132	>	*   // create and start threads
133	>	*   for (final Runnable task : tasks) {
134	>	*     phaser.register();
135	>	*     new Thread() {
136	>	*       public void run() {
137	>	*         phaser.arriveAndAwaitAdvance(); // await all creation
138	>	*         task.run();
139	>	*       }
140	>	*     }.start();
141		*   }
142		*
143	<	*   doSomethingOnBehalfOfWorkers();
144	<	*   phaser.arrive(); // allow threads to start
145	<	*   int p = phaser.arriveAndDeregister(); // deregister self  ...
109	<	*   p = phaser.awaitAdvance(p); // ... and await arrival
110	<	*   otherActions(); // do other things while tasks execute
111	<	*   phaser.awaitAdvance(p); // awit final completion
112	<	* }
113	<	* </pre>
143	>	*   // allow threads to start and deregister self
144	>	*   phaser.arriveAndDeregister();
145	>	* }}</pre>
146		*
147		* <p>One way to cause a set of threads to repeatedly perform actions
148	<	* for a given number of iterations is to override <tt>onAdvance</tt>:
148	>	* for a given number of iterations is to override {@code onAdvance}:
149		*
150	<	* <pre>
151	<	*  void startTasks(List&lt;Runnable&gt; list, final int iterations) {
152	<	*    final Phaser phaser = new Phaser() {
153	<	*       public boolean onAdvance(int phase, int registeredParties) {
154	<	*         return phase &gt;= iterations || registeredParties == 0;
150	>	*  <pre> {@code
151	>	* void startTasks(List<Runnable> tasks, final int iterations) {
152	>	*   final Phaser phaser = new Phaser() {
153	>	*     protected boolean onAdvance(int phase, int registeredParties) {
154	>	*       return phase >= iterations || registeredParties == 0;
155	>	*     }
156	>	*   };
157	>	*   phaser.register();
158	>	*   for (final Runnable task : tasks) {
159	>	*     phaser.register();
160	>	*     new Thread() {
161	>	*       public void run() {
162	>	*         do {
163	>	*           task.run();
164	>	*           phaser.arriveAndAwaitAdvance();
165	>	*         } while (!phaser.isTerminated());
166		*       }
167	<	*    };
125	<	*    phaser.register();
126	<	*    for (Runnable r : list) {
127	<	*      phaser.register();
128	<	*      new Thread() {
129	<	*        public void run() {
130	<	*           do {
131	<	*             r.run();
132	<	*             phaser.arriveAndAwaitAdvance();
133	<	*           } while(!phaser.isTerminated();
134	<	*        }
135	<	*      }.start();
167	>	*     }.start();
168		*   }
169		*   phaser.arriveAndDeregister(); // deregister self, don't wait
170	<	* }
171	<	* </pre>
170	>	* }}</pre>
171	>	*
172	>	* If the main task must later await termination, it
173	>	* may re-register and then execute a similar loop:
174	>	*  <pre> {@code
175	>	*   // ...
176	>	*   phaser.register();
177	>	*   while (!phaser.isTerminated())
178	>	*     phaser.arriveAndAwaitAdvance();}</pre>
179	>	*
180	>	* <p>Related constructions may be used to await particular phase numbers
181	>	* in contexts where you are sure that the phase will never wrap around
182	>	* {@code Integer.MAX_VALUE}. For example:
183	>	*
184	>	*  <pre> {@code
185	>	* void awaitPhase(Phaser phaser, int phase) {
186	>	*   int p = phaser.register(); // assumes caller not already registered
187	>	*   while (p < phase) {
188	>	*     if (phaser.isTerminated())
189	>	*       // ... deal with unexpected termination
190	>	*     else
191	>	*       p = phaser.arriveAndAwaitAdvance();
192	>	*   }
193	>	*   phaser.arriveAndDeregister();
194	>	* }}</pre>
195		*
141	–	* <p> To create a set of tasks using a tree of Phasers,
142	–	* you could use code of the following form, assuming a
143	–	* Task class with a constructor accepting a Phaser that
144	–	* it registers for upon construction:
145	–	* <pre>
146	–	*  void build(Task[] actions, int lo, int hi, Phaser b) {
147	–	*    int step = (hi - lo) / TASKS_PER_PHASER;
148	–	*    if (step &gt; 1) {
149	–	*       int i = lo;
150	–	*       while (i &lt; hi) {
151	–	*         int r = Math.min(i + step, hi);
152	–	*         build(actions, i, r, new Phaser(b));
153	–	*         i = r;
154	–	*       }
155	–	*    }
156	–	*    else {
157	–	*      for (int i = lo; i &lt; hi; ++i)
158	–	*        actions[i] = new Task(b);
159	–	*        // assumes new Task(b) performs b.register()
160	–	*    }
161	–	*  }
162	–	*  // .. initially called, for n tasks via
163	–	*  build(new Task[n], 0, n, new Phaser());
164	–	* </pre>
165	–	*
166	–	* The best value of <tt>TASKS_PER_PHASER</tt> depends mainly on
167	–	* expected barrier synchronization rates. A value as low as four may
168	–	* be appropriate for extremely small per-barrier task bodies (thus
169	–	* high rates), or up to hundreds for extremely large ones.
196		*
197	<	* </pre>
197	>	* <p>To create a set of {@code n} tasks using a tree of phasers, you
198	>	* could use code of the following form, assuming a Task class with a
199	>	* constructor accepting a {@code Phaser} that it registers with upon
200	>	* construction. After invocation of {@code build(new Task[n], 0, n,
201	>	* new Phaser())}, these tasks could then be started, for example by
202	>	* submitting to a pool:
203	>	*
204	>	*  <pre> {@code
205	>	* void build(Task[] tasks, int lo, int hi, Phaser ph) {
206	>	*   if (hi - lo > TASKS_PER_PHASER) {
207	>	*     for (int i = lo; i < hi; i += TASKS_PER_PHASER) {
208	>	*       int j = Math.min(i + TASKS_PER_PHASER, hi);
209	>	*       build(tasks, i, j, new Phaser(ph));
210	>	*     }
211	>	*   } else {
212	>	*     for (int i = lo; i < hi; ++i)
213	>	*       tasks[i] = new Task(ph);
214	>	*       // assumes new Task(ph) performs ph.register()
215	>	*   }
216	>	* }}</pre>
217	>	*
218	>	* The best value of {@code TASKS_PER_PHASER} depends mainly on
219	>	* expected synchronization rates. A value as low as four may
220	>	* be appropriate for extremely small per-phase task bodies (thus
221	>	* high rates), or up to hundreds for extremely large ones.
222		*
223		* <p><b>Implementation notes</b>: This implementation restricts the
224		* maximum number of parties to 65535. Attempts to register additional
225	<	* parties result in IllegalStateExceptions. However, you can and
225	>	* parties result in {@code IllegalStateException}. However, you can and
226		* should create tiered phasers to accommodate arbitrarily large sets
227		* of participants.
228	+	*
229	+	* @since 1.7
230	+	* @author Doug Lea
231		*/
232		public class Phaser {
233		/*
#	Line 184 | Line 237 | public class Phaser {
237		*/
238
239		/**
240	<	* Barrier state representation. Conceptually, a barrier contains
241	<	* four values:
240	>	* Primary state representation, holding four bit-fields:
241	>	*
242	>	* unarrived  -- the number of parties yet to hit barrier (bits  0-15)
243	>	* parties    -- the number of parties to wait            (bits 16-31)
244	>	* phase      -- the generation of the barrier            (bits 32-62)
245	>	* terminated -- set if barrier is terminated             (bit  63 / sign)
246	>	*
247	>	* Except that a phaser with no registered parties is
248	>	* distinguished by the otherwise illegal state of having zero
249	>	* parties and one unarrived parties (encoded as EMPTY below).
250	>	*
251	>	* To efficiently maintain atomicity, these values are packed into
252	>	* a single (atomic) long. Good performance relies on keeping
253	>	* state decoding and encoding simple, and keeping race windows
254	>	* short.
255		*
256	<	* * parties -- the number of parties to wait (16 bits)
257	<	* * unarrived -- the number of parties yet to hit barrier (16 bits)
258	<	* * phase -- the generation of the barrier (31 bits)
259	<	* * terminated -- set if barrier is terminated (1 bit)
260	<	*
195	<	* However, to efficiently maintain atomicity, these values are
196	<	* packed into a single (atomic) long. Termination uses the sign
197	<	* bit of 32 bit representation of phase, so phase is set to -1 on
198	<	* termination. Good performace relies on keeping state decoding
199	<	* and encoding simple, and keeping race windows short.
256	>	* All state updates are performed via CAS except initial
257	>	* registration of a sub-phaser (i.e., one with a non-null
258	>	* parent).  In this (relatively rare) case, we use built-in
259	>	* synchronization to lock while first registering with its
260	>	* parent.
261		*
262	<	* Note: there are some cheats in arrive() that rely on unarrived
263	<	* being lowest 16 bits.
262	>	* The phase of a subphaser is allowed to lag that of its
263	>	* ancestors until it is actually accessed -- see method
264	>	* reconcileState.
265		*/
266		private volatile long state;
267
268	<	private static final int ushortBits = 16;
269	<	private static final int ushortMask =  (1 << ushortBits) - 1;
270	<	private static final int phaseMask = 0x7fffffff;
268	>	private static final int  MAX_PARTIES     = 0xffff;
269	>	private static final int  MAX_PHASE       = Integer.MAX_VALUE;
270	>	private static final int  PARTIES_SHIFT   = 16;
271	>	private static final int  PHASE_SHIFT     = 32;
272	>	private static final int  UNARRIVED_MASK  = 0xffff;      // to mask ints
273	>	private static final long PARTIES_MASK    = 0xffff0000L; // to mask longs
274	>	private static final long TERMINATION_BIT = 1L << 63;
275	>
276	>	// some special values
277	>	private static final int  ONE_ARRIVAL     = 1;
278	>	private static final int  ONE_PARTY       = 1 << PARTIES_SHIFT;
279	>	private static final int  EMPTY           = 1;
280	>
281	>	// The following unpacking methods are usually manually inlined
282
283		private static int unarrivedOf(long s) {
284	<	return (int)(s & ushortMask);
284	>	int counts = (int)s;
285	>	return (counts == EMPTY) ? 0 : counts & UNARRIVED_MASK;
286		}
287
288		private static int partiesOf(long s) {
289	<	return (int)(s & (ushortMask << 16)) >>> 16;
289	>	return (int)s >>> PARTIES_SHIFT;
290		}
291
292		private static int phaseOf(long s) {
293	<	return (int)(s >>> 32);
293	>	return (int)(s >>> PHASE_SHIFT);
294		}
295
296		private static int arrivedOf(long s) {
297	<	return partiesOf(s) - unarrivedOf(s);
298	<	}
299	<
226	<	private static long stateFor(int phase, int parties, int unarrived) {
227	<	return (((long)phase) << 32) | ((parties << 16) | unarrived);
228	<	}
229	<
230	<	private static long trippedStateFor(int phase, int parties) {
231	<	return (((long)phase) << 32) | ((parties << 16) | parties);
232	<	}
233	<
234	<	private static IllegalStateException badBounds(int parties, int unarrived) {
235	<	return new IllegalStateException
236	<	("Attempt to set " + unarrived +
237	<	" unarrived of " + parties + " parties");
297	>	int counts = (int)s;
298	>	return (counts == EMPTY) ? 0 :
299	>	(counts >>> PARTIES_SHIFT) - (counts & UNARRIVED_MASK);
300		}
301
302		/**
#	Line 243 | Line 305 | public class Phaser {
305		private final Phaser parent;
306
307		/**
308	<	* The root of Phaser tree. Equals this if not in a tree.  Used to
247	<	* support faster state push-down.
308	>	* The root of phaser tree. Equals this if not in a tree.
309		*/
310		private final Phaser root;
311
251	–	// Wait queues
252	–
312		/**
313	<	* Heads of Treiber stacks waiting for nonFJ threads. To eliminate
314	<	* contention while releasing some threads while adding others, we
313	>	* Heads of Treiber stacks for waiting threads. To eliminate
314	>	* contention when releasing some threads while adding others, we
315		* use two of them, alternating across even and odd phases.
316	+	* Subphasers share queues with root to speed up releases.
317		*/
318	<	private final AtomicReference<QNode> evenQ = new AtomicReference<QNode>();
319	<	private final AtomicReference<QNode> oddQ  = new AtomicReference<QNode>();
318	>	private final AtomicReference<QNode> evenQ;
319	>	private final AtomicReference<QNode> oddQ;
320
321		private AtomicReference<QNode> queueFor(int phase) {
322	<	return (phase & 1) == 0? evenQ : oddQ;
322	>	return ((phase & 1) == 0) ? evenQ : oddQ;
323		}
324
325		/**
326	<	* Returns current state, first resolving lagged propagation from
267	<	* root if necessary.
326	>	* Returns message string for bounds exceptions on arrival.
327		*/
328	<	private long getReconciledState() {
329	<	return parent == null? state : reconcileState();
328	>	private String badArrive(long s) {
329	>	return "Attempted arrival of unregistered party for " +
330	>	stateToString(s);
331		}
332
333		/**
334	<	* Recursively resolves state.
334	>	* Returns message string for bounds exceptions on registration.
335		*/
336	<	private long reconcileState() {
337	<	Phaser p = parent;
338	<	long s = state;
339	<	if (p != null) {
340	<	while (unarrivedOf(s) == 0 && phaseOf(s) != phaseOf(root.state)) {
341	<	long parentState = p.getReconciledState();
342	<	int parentPhase = phaseOf(parentState);
343	<	int phase = phaseOf(s = state);
344	<	if (phase != parentPhase) {
345	<	long next = trippedStateFor(parentPhase, partiesOf(s));
346	<	if (casState(s, next)) {
347	<	releaseWaiters(phase);
348	<	s = next;
336	>	private String badRegister(long s) {
337	>	return "Attempt to register more than " +
338	>	MAX_PARTIES + " parties for " + stateToString(s);
339	>	}
340	>
341	>	/**
342	>	* Main implementation for methods arrive and arriveAndDeregister.
343	>	* Manually tuned to speed up and minimize race windows for the
344	>	* common case of just decrementing unarrived field.
345	>	*
346	>	* @param deregister false for arrive, true for arriveAndDeregister
347	>	*/
348	>	private int doArrive(boolean deregister) {
349	>	int adj = deregister ? ONE_ARRIVAL|ONE_PARTY : ONE_ARRIVAL;
350	>	final Phaser root = this.root;
351	>	for (;;) {
352	>	long s = (root == this) ? state : reconcileState();
353	>	int phase = (int)(s >>> PHASE_SHIFT);
354	>	int counts = (int)s;
355	>	int unarrived = (counts & UNARRIVED_MASK) - 1;
356	>	if (phase < 0)
357	>	return phase;
358	>	else if (counts == EMPTY || unarrived < 0) {
359	>	if (root == this || reconcileState() == s)
360	>	throw new IllegalStateException(badArrive(s));
361	>	}
362	>	else if (UNSAFE.compareAndSwapLong(this, stateOffset, s, s-=adj)) {
363	>	long n = s & PARTIES_MASK;  // base of next state
364	>	int nextUnarrived = (int)n >>> PARTIES_SHIFT;
365	>	if (unarrived == 0) {
366	>	if (root == this) {
367	>	if (onAdvance(phase, nextUnarrived))
368	>	n |= TERMINATION_BIT;
369	>	else if (nextUnarrived == 0)
370	>	n |= EMPTY;
371	>	else
372	>	n |= nextUnarrived;
373	>	n |= (long)((phase + 1) & MAX_PHASE) << PHASE_SHIFT;
374	>	UNSAFE.compareAndSwapLong(this, stateOffset, s, n);
375		}
376	+	else if (nextUnarrived == 0) { // propagate deregistration
377	+	phase = parent.doArrive(true);
378	+	UNSAFE.compareAndSwapLong(this, stateOffset,
379	+	s, s | EMPTY);
380	+	}
381	+	else
382	+	phase = parent.doArrive(false);
383	+	releaseWaiters(phase);
384		}
385	+	return phase;
386		}
387		}
388	+	}
389	+
390	+	/**
391	+	* Implementation of register, bulkRegister
392	+	*
393	+	* @param registrations number to add to both parties and
394	+	* unarrived fields. Must be greater than zero.
395	+	*/
396	+	private int doRegister(int registrations) {
397	+	// adjustment to state
398	+	long adj = ((long)registrations << PARTIES_SHIFT) | registrations;
399	+	final Phaser parent = this.parent;
400	+	int phase;
401	+	for (;;) {
402	+	long s = (parent == null) ? state : reconcileState();
403	+	int counts = (int)s;
404	+	int parties = counts >>> PARTIES_SHIFT;
405	+	int unarrived = counts & UNARRIVED_MASK;
406	+	if (registrations > MAX_PARTIES - parties)
407	+	throw new IllegalStateException(badRegister(s));
408	+	else if ((phase = (int)(s >>> PHASE_SHIFT)) < 0)
409	+	break;
410	+	else if (counts != EMPTY) {             // not 1st registration
411	+	if (parent == null || reconcileState() == s) {
412	+	if (unarrived == 0)             // wait out advance
413	+	root.internalAwaitAdvance(phase, null);
414	+	else if (UNSAFE.compareAndSwapLong(this, stateOffset,
415	+	s, s + adj))
416	+	break;
417	+	}
418	+	}
419	+	else if (parent == null) {              // 1st root registration
420	+	long next = ((long)phase << PHASE_SHIFT) | adj;
421	+	if (UNSAFE.compareAndSwapLong(this, stateOffset, s, next))
422	+	break;
423	+	}
424	+	else {
425	+	synchronized (this) {               // 1st sub registration
426	+	if (state == s) {               // recheck under lock
427	+	parent.doRegister(1);
428	+	do {                        // force current phase
429	+	phase = (int)(root.state >>> PHASE_SHIFT);
430	+	// assert phase < 0 || (int)state == EMPTY;
431	+	} while (!UNSAFE.compareAndSwapLong
432	+	(this, stateOffset, state,
433	+	((long)phase << PHASE_SHIFT) | adj));
434	+	break;
435	+	}
436	+	}
437	+	}
438	+	}
439	+	return phase;
440	+	}
441	+
442	+	/**
443	+	* Resolves lagged phase propagation from root if necessary.
444	+	* Reconciliation normally occurs when root has advanced but
445	+	* subphasers have not yet done so, in which case they must finish
446	+	* their own advance by setting unarrived to parties (or if
447	+	* parties is zero, resetting to unregistered EMPTY state).
448	+	* However, this method may also be called when "floating"
449	+	* subphasers with possibly some unarrived parties are merely
450	+	* catching up to current phase, in which case counts are
451	+	* unaffected.
452	+	*
453	+	* @return reconciled state
454	+	*/
455	+	private long reconcileState() {
456	+	final Phaser root = this.root;
457	+	long s = state;
458	+	if (root != this) {
459	+	int phase, u, p;
460	+	// CAS root phase with current parties; possibly trip unarrived
461	+	while ((phase = (int)(root.state >>> PHASE_SHIFT)) !=
462	+	(int)(s >>> PHASE_SHIFT) &&
463	+	!UNSAFE.compareAndSwapLong
464	+	(this, stateOffset, s,
465	+	s = (((long)phase << PHASE_SHIFT) |
466	+	(s & PARTIES_MASK) |
467	+	((p = (int)s >>> PARTIES_SHIFT) == 0 ? EMPTY :
468	+	((u = (int)s & UNARRIVED_MASK) == 0 && phase >= 0) ?
469	+	p : u))))
470	+	s = state;
471	+	}
472		return s;
473		}
474
475		/**
476	<	* Creates a new Phaser without any initially registered parties,
477	<	* initial phase number 0, and no parent.
476	>	* Creates a new phaser with no initially registered parties, no
477	>	* parent, and initial phase number 0. Any thread using this
478	>	* phaser will need to first register for it.
479		*/
480		public Phaser() {
481	<	this(null);
481	>	this(null, 0);
482		}
483
484		/**
485	<	* Creates a new Phaser with the given numbers of registered
486	<	* unarrived parties, initial phase number 0, and no parent.
487	<	* @param parties the number of parties required to trip barrier.
485	>	* Creates a new phaser with the given number of registered
486	>	* unarrived parties, no parent, and initial phase number 0.
487	>	*
488	>	* @param parties the number of parties required to advance to the
489	>	* next phase
490		* @throws IllegalArgumentException if parties less than zero
491	<	* or greater than the maximum number of parties supported.
491	>	* or greater than the maximum number of parties supported
492		*/
493		public Phaser(int parties) {
494		this(null, parties);
495		}
496
497		/**
498	<	* Creates a new Phaser with the given parent, without any
499	<	* initially registered parties. If parent is non-null this phaser
500	<	* is registered with the parent and its initial phase number is
319	<	* the same as that of parent phaser.
320	<	* @param parent the parent phaser.
498	>	* Equivalent to {@link #Phaser(Phaser, int) Phaser(parent, 0)}.
499	>	*
500	>	* @param parent the parent phaser
501		*/
502		public Phaser(Phaser parent) {
503	<	int phase = 0;
324	<	this.parent = parent;
325	<	if (parent != null) {
326	<	this.root = parent.root;
327	<	phase = parent.register();
328	<	}
329	<	else
330	<	this.root = this;
331	<	this.state = trippedStateFor(phase, 0);
503	>	this(parent, 0);
504		}
505
506		/**
507	<	* Creates a new Phaser with the given parent and numbers of
508	<	* registered unarrived parties. If parent is non-null this phaser
509	<	* is registered with the parent and its initial phase number is
510	<	* the same as that of parent phaser.
511	<	* @param parent the parent phaser.
512	<	* @param parties the number of parties required to trip barrier.
507	>	* Creates a new phaser with the given parent and number of
508	>	* registered unarrived parties.  When the given parent is non-null
509	>	* and the given number of parties is greater than zero, this
510	>	* child phaser is registered with its parent.
511	>	*
512	>	* @param parent the parent phaser
513	>	* @param parties the number of parties required to advance to the
514	>	* next phase
515		* @throws IllegalArgumentException if parties less than zero
516	<	* or greater than the maximum number of parties supported.
516	>	* or greater than the maximum number of parties supported
517		*/
518		public Phaser(Phaser parent, int parties) {
519	<	if (parties < 0 || parties > ushortMask)
519	>	if (parties >>> PARTIES_SHIFT != 0)
520		throw new IllegalArgumentException("Illegal number of parties");
521		int phase = 0;
522		this.parent = parent;
523		if (parent != null) {
524	<	this.root = parent.root;
525	<	phase = parent.register();
524	>	final Phaser root = parent.root;
525	>	this.root = root;
526	>	this.evenQ = root.evenQ;
527	>	this.oddQ = root.oddQ;
528	>	if (parties != 0)
529	>	phase = parent.doRegister(1);
530		}
531	<	else
531	>	else {
532		this.root = this;
533	<	this.state = trippedStateFor(phase, parties);
533	>	this.evenQ = new AtomicReference<QNode>();
534	>	this.oddQ = new AtomicReference<QNode>();
535	>	}
536	>	this.state = (parties == 0) ? (long)EMPTY :
537	>	((long)phase << PHASE_SHIFT) |
538	>	((long)parties << PARTIES_SHIFT) |
539	>	((long)parties);
540		}
541
542		/**
543	<	* Adds a new unarrived party to this phaser.
544	<	* @return the current barrier phase number upon registration
543	>	* Adds a new unarrived party to this phaser.  If an ongoing
544	>	* invocation of {@link #onAdvance} is in progress, this method
545	>	* may await its completion before returning.  If this phaser has
546	>	* a parent, and this phaser previously had no registered parties,
547	>	* this child phaser is also registered with its parent. If
548	>	* this phaser is terminated, the attempt to register has
549	>	* no effect, and a negative value is returned.
550	>	*
551	>	* @return the arrival phase number to which this registration
552	>	* applied.  If this value is negative, then this phaser has
553	>	* terminated, in which case registration has no effect.
554		* @throws IllegalStateException if attempting to register more
555	<	* than the maximum supported number of parties.
555	>	* than the maximum supported number of parties
556		*/
557		public int register() {
558		return doRegister(1);
#	Line 367 | Line 560 | public class Phaser {
560
561		/**
562		* Adds the given number of new unarrived parties to this phaser.
563	<	* @param parties the number of parties required to trip barrier.
564	<	* @return the current barrier phase number upon registration
563	>	* If an ongoing invocation of {@link #onAdvance} is in progress,
564	>	* this method may await its completion before returning.  If this
565	>	* phaser has a parent, and the given number of parties is greater
566	>	* than zero, and this phaser previously had no registered
567	>	* parties, this child phaser is also registered with its parent.
568	>	* If this phaser is terminated, the attempt to register has no
569	>	* effect, and a negative value is returned.
570	>	*
571	>	* @param parties the number of additional parties required to
572	>	* advance to the next phase
573	>	* @return the arrival phase number to which this registration
574	>	* applied.  If this value is negative, then this phaser has
575	>	* terminated, in which case registration has no effect.
576		* @throws IllegalStateException if attempting to register more
577	<	* than the maximum supported number of parties.
577	>	* than the maximum supported number of parties
578	>	* @throws IllegalArgumentException if {@code parties < 0}
579		*/
580		public int bulkRegister(int parties) {
581		if (parties < 0)
#	Line 381 | Line 586 | public class Phaser {
586		}
587
588		/**
589	<	* Shared code for register, bulkRegister
590	<	*/
591	<	private int doRegister(int registrations) {
592	<	int phase;
593	<	for (;;) {
594	<	long s = getReconciledState();
390	<	phase = phaseOf(s);
391	<	int unarrived = unarrivedOf(s) + registrations;
392	<	int parties = partiesOf(s) + registrations;
393	<	if (phase < 0)
394	<	break;
395	<	if (parties > ushortMask || unarrived > ushortMask)
396	<	throw badBounds(parties, unarrived);
397	<	if (phase == phaseOf(root.state) &&
398	<	casState(s, stateFor(phase, parties, unarrived)))
399	<	break;
400	<	}
401	<	return phase;
402	<	}
403	<
404	<	/**
405	<	* Arrives at the barrier, but does not wait for others.  (You can
406	<	* in turn wait for others via {@link #awaitAdvance}).
589	>	* Arrives at this phaser, without waiting for others to arrive.
590	>	*
591	>	* <p>It is a usage error for an unregistered party to invoke this
592	>	* method.  However, this error may result in an {@code
593	>	* IllegalStateException} only upon some subsequent operation on
594	>	* this phaser, if ever.
595		*
596	<	* @return the barrier phase number upon entry to this method, or a
409	<	* negative value if terminated;
596	>	* @return the arrival phase number, or a negative value if terminated
597		* @throws IllegalStateException if not terminated and the number
598	<	* of unarrived parties would become negative.
598	>	* of unarrived parties would become negative
599		*/
600		public int arrive() {
601	<	int phase;
415	<	for (;;) {
416	<	long s = state;
417	<	phase = phaseOf(s);
418	<	int parties = partiesOf(s);
419	<	int unarrived = unarrivedOf(s) - 1;
420	<	if (unarrived > 0) {        // Not the last arrival
421	<	if (casState(s, s - 1)) // s-1 adds one arrival
422	<	break;
423	<	}
424	<	else if (unarrived == 0) {  // the last arrival
425	<	Phaser par = parent;
426	<	if (par == null) {      // directly trip
427	<	if (casState
428	<	(s,
429	<	trippedStateFor(onAdvance(phase, parties)? -1 :
430	<	((phase + 1) & phaseMask), parties))) {
431	<	releaseWaiters(phase);
432	<	break;
433	<	}
434	<	}
435	<	else {                  // cascade to parent
436	<	if (casState(s, s - 1)) { // zeroes unarrived
437	<	par.arrive();
438	<	reconcileState();
439	<	break;
440	<	}
441	<	}
442	<	}
443	<	else if (phase < 0) // Don't throw exception if terminated
444	<	break;
445	<	else if (phase != phaseOf(root.state)) // or if unreconciled
446	<	reconcileState();
447	<	else
448	<	throw badBounds(parties, unarrived);
449	<	}
450	<	return phase;
601	>	return doArrive(false);
602		}
603
604		/**
605	<	* Arrives at the barrier, and deregisters from it, without
606	<	* waiting for others. Deregistration reduces number of parties
607	<	* required to trip the barrier in future phases.  If this phaser
605	>	* Arrives at this phaser and deregisters from it without waiting
606	>	* for others to arrive. Deregistration reduces the number of
607	>	* parties required to advance in future phases.  If this phaser
608		* has a parent, and deregistration causes this phaser to have
609		* zero parties, this phaser is also deregistered from its parent.
610		*
611	<	* @return the current barrier phase number upon entry to
612	<	* this method, or a negative value if terminated;
611	>	* <p>It is a usage error for an unregistered party to invoke this
612	>	* method.  However, this error may result in an {@code
613	>	* IllegalStateException} only upon some subsequent operation on
614	>	* this phaser, if ever.
615	>	*
616	>	* @return the arrival phase number, or a negative value if terminated
617		* @throws IllegalStateException if not terminated and the number
618	<	* of registered or unarrived parties would become negative.
618	>	* of registered or unarrived parties would become negative
619		*/
620		public int arriveAndDeregister() {
621	<	// similar code to arrive, but too different to merge
467	<	Phaser par = parent;
468	<	int phase;
469	<	for (;;) {
470	<	long s = state;
471	<	phase = phaseOf(s);
472	<	int parties = partiesOf(s) - 1;
473	<	int unarrived = unarrivedOf(s) - 1;
474	<	if (parties >= 0) {
475	<	if (unarrived > 0 || (unarrived == 0 && par != null)) {
476	<	if (casState
477	<	(s,
478	<	stateFor(phase, parties, unarrived))) {
479	<	if (unarrived == 0) {
480	<	par.arriveAndDeregister();
481	<	reconcileState();
482	<	}
483	<	break;
484	<	}
485	<	continue;
486	<	}
487	<	if (unarrived == 0) {
488	<	if (casState
489	<	(s,
490	<	trippedStateFor(onAdvance(phase, parties)? -1 :
491	<	((phase + 1) & phaseMask), parties))) {
492	<	releaseWaiters(phase);
493	<	break;
494	<	}
495	<	continue;
496	<	}
497	<	if (phase < 0)
498	<	break;
499	<	if (par != null && phase != phaseOf(root.state)) {
500	<	reconcileState();
501	<	continue;
502	<	}
503	<	}
504	<	throw badBounds(parties, unarrived);
505	<	}
506	<	return phase;
621	>	return doArrive(true);
622		}
623
624		/**
625	<	* Arrives at the barrier and awaits others. Equivalent in effect
626	<	* to <tt>awaitAdvance(arrive())</tt>.  If you instead need to
627	<	* await with interruption of timeout, and/or deregister upon
628	<	* arrival, you can arrange them using analogous constructions.
629	<	* @return the phase on entry to this method
625	>	* Arrives at this phaser and awaits others. Equivalent in effect
626	>	* to {@code awaitAdvance(arrive())}.  If you need to await with
627	>	* interruption or timeout, you can arrange this with an analogous
628	>	* construction using one of the other forms of the {@code
629	>	* awaitAdvance} method.  If instead you need to deregister upon
630	>	* arrival, use {@code awaitAdvance(arriveAndDeregister())}.
631	>	*
632	>	* <p>It is a usage error for an unregistered party to invoke this
633	>	* method.  However, this error may result in an {@code
634	>	* IllegalStateException} only upon some subsequent operation on
635	>	* this phaser, if ever.
636	>	*
637	>	* @return the arrival phase number, or the (negative)
638	>	* {@linkplain #getPhase() current phase} if terminated
639		* @throws IllegalStateException if not terminated and the number
640	<	* of unarrived parties would become negative.
640	>	* of unarrived parties would become negative
641		*/
642		public int arriveAndAwaitAdvance() {
643	<	return awaitAdvance(arrive());
643	>	// Specialization of doArrive+awaitAdvance eliminating some reads/paths
644	>	final Phaser root = this.root;
645	>	for (;;) {
646	>	long s = (root == this) ? state : reconcileState();
647	>	int phase = (int)(s >>> PHASE_SHIFT);
648	>	int counts = (int)s;
649	>	int unarrived = (counts & UNARRIVED_MASK) - 1;
650	>	if (phase < 0)
651	>	return phase;
652	>	else if (counts == EMPTY || unarrived < 0) {
653	>	if (reconcileState() == s)
654	>	throw new IllegalStateException(badArrive(s));
655	>	}
656	>	else if (UNSAFE.compareAndSwapLong(this, stateOffset, s,
657	>	s -= ONE_ARRIVAL)) {
658	>	if (unarrived != 0)
659	>	return root.internalAwaitAdvance(phase, null);
660	>	if (root != this)
661	>	return parent.arriveAndAwaitAdvance();
662	>	long n = s & PARTIES_MASK;  // base of next state
663	>	int nextUnarrived = (int)n >>> PARTIES_SHIFT;
664	>	if (onAdvance(phase, nextUnarrived))
665	>	n |= TERMINATION_BIT;
666	>	else if (nextUnarrived == 0)
667	>	n |= EMPTY;
668	>	else
669	>	n |= nextUnarrived;
670	>	int nextPhase = (phase + 1) & MAX_PHASE;
671	>	n |= (long)nextPhase << PHASE_SHIFT;
672	>	if (!UNSAFE.compareAndSwapLong(this, stateOffset, s, n))
673	>	return (int)(state >>> PHASE_SHIFT); // terminated
674	>	releaseWaiters(phase);
675	>	return nextPhase;
676	>	}
677	>	}
678		}
679
680		/**
681	<	* Awaits the phase of the barrier to advance from the given
682	<	* value, or returns immediately if argument is negative or this
683	<	* barrier is terminated.
684	<	* @param phase the phase on entry to this method
685	<	* @return the phase on exit from this method
681	>	* Awaits the phase of this phaser to advance from the given phase
682	>	* value, returning immediately if the current phase is not equal
683	>	* to the given phase value or this phaser is terminated.
684	>	*
685	>	* @param phase an arrival phase number, or negative value if
686	>	* terminated; this argument is normally the value returned by a
687	>	* previous call to {@code arrive} or {@code arriveAndDeregister}.
688	>	* @return the next arrival phase number, or the argument if it is
689	>	* negative, or the (negative) {@linkplain #getPhase() current phase}
690	>	* if terminated
691		*/
692		public int awaitAdvance(int phase) {
693	+	final Phaser root = this.root;
694	+	long s = (root == this) ? state : reconcileState();
695	+	int p = (int)(s >>> PHASE_SHIFT);
696		if (phase < 0)
697		return phase;
698	<	long s = getReconciledState();
699	<	int p = phaseOf(s);
700	<	if (p != phase)
535	<	return p;
536	<	if (unarrivedOf(s) == 0)
537	<	parent.awaitAdvance(phase);
538	<	// Fall here even if parent waited, to reconcile and help release
539	<	return untimedWait(phase);
698	>	if (p == phase)
699	>	return root.internalAwaitAdvance(phase, null);
700	>	return p;
701		}
702
703		/**
704	<	* Awaits the phase of the barrier to advance from the given
705	<	* value, or returns immediately if argumet is negative or this
706	<	* barrier is terminated, or throws InterruptedException if
707	<	* interrupted while waiting.
708	<	* @param phase the phase on entry to this method
709	<	* @return the phase on exit from this method
704	>	* Awaits the phase of this phaser to advance from the given phase
705	>	* value, throwing {@code InterruptedException} if interrupted
706	>	* while waiting, or returning immediately if the current phase is
707	>	* not equal to the given phase value or this phaser is
708	>	* terminated.
709	>	*
710	>	* @param phase an arrival phase number, or negative value if
711	>	* terminated; this argument is normally the value returned by a
712	>	* previous call to {@code arrive} or {@code arriveAndDeregister}.
713	>	* @return the next arrival phase number, or the argument if it is
714	>	* negative, or the (negative) {@linkplain #getPhase() current phase}
715	>	* if terminated
716		* @throws InterruptedException if thread interrupted while waiting
717		*/
718	<	public int awaitAdvanceInterruptibly(int phase) throws InterruptedException {
718	>	public int awaitAdvanceInterruptibly(int phase)
719	>	throws InterruptedException {
720	>	final Phaser root = this.root;
721	>	long s = (root == this) ? state : reconcileState();
722	>	int p = (int)(s >>> PHASE_SHIFT);
723		if (phase < 0)
724		return phase;
725	<	long s = getReconciledState();
726	<	int p = phaseOf(s);
727	<	if (p != phase)
728	<	return p;
729	<	if (unarrivedOf(s) != 0)
730	<	parent.awaitAdvanceInterruptibly(phase);
731	<	return interruptibleWait(phase);
725	>	if (p == phase) {
726	>	QNode node = new QNode(this, phase, true, false, 0L);
727	>	p = root.internalAwaitAdvance(phase, node);
728	>	if (node.wasInterrupted)
729	>	throw new InterruptedException();
730	>	}
731	>	return p;
732		}
733
734		/**
735	<	* Awaits the phase of the barrier to advance from the given value
736	<	* or the given timeout elapses, or returns immediately if
737	<	* argument is negative or this barrier is terminated.
738	<	* @param phase the phase on entry to this method
739	<	* @return the phase on exit from this method
735	>	* Awaits the phase of this phaser to advance from the given phase
736	>	* value or the given timeout to elapse, throwing {@code
737	>	* InterruptedException} if interrupted while waiting, or
738	>	* returning immediately if the current phase is not equal to the
739	>	* given phase value or this phaser is terminated.
740	>	*
741	>	* @param phase an arrival phase number, or negative value if
742	>	* terminated; this argument is normally the value returned by a
743	>	* previous call to {@code arrive} or {@code arriveAndDeregister}.
744	>	* @param timeout how long to wait before giving up, in units of
745	>	*        {@code unit}
746	>	* @param unit a {@code TimeUnit} determining how to interpret the
747	>	*        {@code timeout} parameter
748	>	* @return the next arrival phase number, or the argument if it is
749	>	* negative, or the (negative) {@linkplain #getPhase() current phase}
750	>	* if terminated
751		* @throws InterruptedException if thread interrupted while waiting
752		* @throws TimeoutException if timed out while waiting
753		*/
754	<	public int awaitAdvanceInterruptibly(int phase, long timeout, TimeUnit unit)
754	>	public int awaitAdvanceInterruptibly(int phase,
755	>	long timeout, TimeUnit unit)
756		throws InterruptedException, TimeoutException {
757	+	long nanos = unit.toNanos(timeout);
758	+	final Phaser root = this.root;
759	+	long s = (root == this) ? state : reconcileState();
760	+	int p = (int)(s >>> PHASE_SHIFT);
761		if (phase < 0)
762		return phase;
763	<	long s = getReconciledState();
764	<	int p = phaseOf(s);
765	<	if (p != phase)
766	<	return p;
767	<	if (unarrivedOf(s) == 0)
768	<	parent.awaitAdvanceInterruptibly(phase, timeout, unit);
769	<	return timedWait(phase, unit.toNanos(timeout));
763	>	if (p == phase) {
764	>	QNode node = new QNode(this, phase, true, true, nanos);
765	>	p = root.internalAwaitAdvance(phase, node);
766	>	if (node.wasInterrupted)
767	>	throw new InterruptedException();
768	>	else if (p == phase)
769	>	throw new TimeoutException();
770	>	}
771	>	return p;
772		}
773
774		/**
775	<	* Forces this barrier to enter termination state. Counts of
776	<	* arrived and registered parties are unaffected. If this phaser
777	<	* has a parent, it too is terminated. This method may be useful
778	<	* for coordinating recovery after one or more tasks encounter
775	>	* Forces this phaser to enter termination state.  Counts of
776	>	* registered parties are unaffected.  If this phaser is a member
777	>	* of a tiered set of phasers, then all of the phasers in the set
778	>	* are terminated.  If this phaser is already terminated, this
779	>	* method has no effect.  This method may be useful for
780	>	* coordinating recovery after one or more tasks encounter
781		* unexpected exceptions.
782		*/
783		public void forceTermination() {
784	<	for (;;) {
785	<	long s = getReconciledState();
786	<	int phase = phaseOf(s);
787	<	int parties = partiesOf(s);
788	<	int unarrived = unarrivedOf(s);
789	<	if (phase < 0 ||
790	<	casState(s, stateFor(-1, parties, unarrived))) {
784	>	// Only need to change root state
785	>	final Phaser root = this.root;
786	>	long s;
787	>	while ((s = root.state) >= 0) {
788	>	if (UNSAFE.compareAndSwapLong(root, stateOffset,
789	>	s, s | TERMINATION_BIT)) {
790	>	// signal all threads
791		releaseWaiters(0);
792		releaseWaiters(1);
602	–	if (parent != null)
603	–	parent.forceTermination();
793		return;
794		}
795		}
#	Line 608 | Line 797 | public class Phaser {
797
798		/**
799		* Returns the current phase number. The maximum phase number is
800	<	* <tt>Integer.MAX_VALUE</tt>, after which it restarts at
801	<	* zero. Upon termination, the phase number is negative.
800	>	* {@code Integer.MAX_VALUE}, after which it restarts at
801	>	* zero. Upon termination, the phase number is negative,
802	>	* in which case the prevailing phase prior to termination
803	>	* may be obtained via {@code getPhase() + Integer.MIN_VALUE}.
804	>	*
805		* @return the phase number, or a negative value if terminated
806		*/
807		public final int getPhase() {
808	<	return phaseOf(getReconciledState());
808	>	return (int)(root.state >>> PHASE_SHIFT);
809		}
810
811		/**
812	<	* Returns true if the current phase number equals the given phase.
813	<	* @param phase the phase
622	<	* @return true if the current phase number equals the given phase.
623	<	*/
624	<	public final boolean hasPhase(int phase) {
625	<	return phaseOf(getReconciledState()) == phase;
626	<	}
627	<
628	<	/**
629	<	* Returns the number of parties registered at this barrier.
812	>	* Returns the number of parties registered at this phaser.
813	>	*
814		* @return the number of parties
815		*/
816		public int getRegisteredParties() {
#	Line 634 | Line 818 | public class Phaser {
818		}
819
820		/**
821	<	* Returns the number of parties that have arrived at the current
822	<	* phase of this barrier.
821	>	* Returns the number of registered parties that have arrived at
822	>	* the current phase of this phaser. If this phaser has terminated,
823	>	* the returned value is meaningless and arbitrary.
824	>	*
825		* @return the number of arrived parties
826		*/
827		public int getArrivedParties() {
828	<	return arrivedOf(state);
828	>	return arrivedOf(reconcileState());
829		}
830
831		/**
832		* Returns the number of registered parties that have not yet
833	<	* arrived at the current phase of this barrier.
833	>	* arrived at the current phase of this phaser. If this phaser has
834	>	* terminated, the returned value is meaningless and arbitrary.
835	>	*
836		* @return the number of unarrived parties
837		*/
838		public int getUnarrivedParties() {
839	<	return unarrivedOf(state);
839	>	return unarrivedOf(reconcileState());
840		}
841
842		/**
843	<	* Returns the parent of this phaser, or null if none.
844	<	* @return the parent of this phaser, or null if none.
843	>	* Returns the parent of this phaser, or {@code null} if none.
844	>	*
845	>	* @return the parent of this phaser, or {@code null} if none
846		*/
847		public Phaser getParent() {
848		return parent;
#	Line 662 | Line 851 | public class Phaser {
851		/**
852		* Returns the root ancestor of this phaser, which is the same as
853		* this phaser if it has no parent.
854	<	* @return the root ancestor of this phaser.
854	>	*
855	>	* @return the root ancestor of this phaser
856		*/
857		public Phaser getRoot() {
858		return root;
859		}
860
861		/**
862	<	* Returns true if this barrier has been terminated.
863	<	* @return true if this barrier has been terminated
862	>	* Returns {@code true} if this phaser has been terminated.
863	>	*
864	>	* @return {@code true} if this phaser has been terminated
865		*/
866		public boolean isTerminated() {
867	<	return getPhase() < 0;
867	>	return root.state < 0L;
868		}
869
870		/**
871	<	* Overridable method to perform an action upon phase advance, and
872	<	* to control termination. This method is invoked whenever the
873	<	* barrier is tripped (and thus all other waiting parties are
874	<	* dormant). If it returns true, then, rather than advance the
875	<	* phase number, this barrier will be set to a final termination
876	<	* state, and subsequent calls to <tt>isTerminated</tt> will
877	<	* return true.
878	<	*
879	<	* <p> The default version returns true when the number of
880	<	* registered parties is zero. Normally, overrides that arrange
881	<	* termination for other reasons should also preserve this
882	<	* property.
883	<	*
884	<	* <p> You may override this method to perform an action with side
885	<	* effects visible to participating tasks, but it is in general
886	<	* only sensible to do so in designs where all parties register
887	<	* before any arrive, and all <tt>awaitAdvance</tt> at each phase.
888	<	* Otherwise, you cannot ensure lack of interference. In
889	<	* particular, this method may be invoked more than once per
890	<	* transition if other parties successfully register while the
891	<	* invocation of this method is in progress, thus postponing the
892	<	* transition until those parties also arrive, re-triggering this
893	<	* method.
894	<	*
895	<	* @param phase the phase number on entering the barrier
896	<	* @param registeredParties the current number of registered
897	<	* parties.
898	<	* @return true if this barrier should terminate
871	>	* Overridable method to perform an action upon impending phase
872	>	* advance, and to control termination. This method is invoked
873	>	* upon arrival of the party advancing this phaser (when all other
874	>	* waiting parties are dormant).  If this method returns {@code
875	>	* true}, this phaser will be set to a final termination state
876	>	* upon advance, and subsequent calls to {@link #isTerminated}
877	>	* will return true. Any (unchecked) Exception or Error thrown by
878	>	* an invocation of this method is propagated to the party
879	>	* attempting to advance this phaser, in which case no advance
880	>	* occurs.
881	>	*
882	>	* <p>The arguments to this method provide the state of the phaser
883	>	* prevailing for the current transition.  The effects of invoking
884	>	* arrival, registration, and waiting methods on this phaser from
885	>	* within {@code onAdvance} are unspecified and should not be
886	>	* relied on.
887	>	*
888	>	* <p>If this phaser is a member of a tiered set of phasers, then
889	>	* {@code onAdvance} is invoked only for its root phaser on each
890	>	* advance.
891	>	*
892	>	* <p>To support the most common use cases, the default
893	>	* implementation of this method returns {@code true} when the
894	>	* number of registered parties has become zero as the result of a
895	>	* party invoking {@code arriveAndDeregister}.  You can disable
896	>	* this behavior, thus enabling continuation upon future
897	>	* registrations, by overriding this method to always return
898	>	* {@code false}:
899	>	*
900	>	* <pre> {@code
901	>	* Phaser phaser = new Phaser() {
902	>	*   protected boolean onAdvance(int phase, int parties) { return false; }
903	>	* }}</pre>
904	>	*
905	>	* @param phase the current phase number on entry to this method,
906	>	* before this phaser is advanced
907	>	* @param registeredParties the current number of registered parties
908	>	* @return {@code true} if this phaser should terminate
909		*/
910		protected boolean onAdvance(int phase, int registeredParties) {
911	<	return registeredParties <= 0;
911	>	return registeredParties == 0;
912		}
913
914		/**
915		* Returns a string identifying this phaser, as well as its
916		* state.  The state, in brackets, includes the String {@code
917	<	* "phase ="} followed by the phase number, {@code "parties ="}
917	>	* "phase = "} followed by the phase number, {@code "parties = "}
918		* followed by the number of registered parties, and {@code
919	<	* "arrived ="} followed by the number of arrived parties
919	>	* "arrived = "} followed by the number of arrived parties.
920		*
921	<	* @return a string identifying this barrier, as well as its state
921	>	* @return a string identifying this phaser, as well as its state
922		*/
923		public String toString() {
924	<	long s = getReconciledState();
724	<	return super.toString() + "[phase = " + phaseOf(s) + " parties = " + partiesOf(s) + " arrived = " + arrivedOf(s) + "]";
924	>	return stateToString(reconcileState());
925		}
926
727	–	// methods for waiting
728	–
729	–	/** The number of CPUs, for spin control */
730	–	static final int NCPUS = Runtime.getRuntime().availableProcessors();
731	–
732	–	/**
733	–	* The number of times to spin before blocking in timed waits.
734	–	* The value is empirically derived.
735	–	*/
736	–	static final int maxTimedSpins = (NCPUS < 2)? 0 : 32;
737	–
927		/**
928	<	* The number of times to spin before blocking in untimed waits.
740	<	* This is greater than timed value because untimed waits spin
741	<	* faster since they don't need to check times on each spin.
928	>	* Implementation of toString and string-based error messages
929		*/
930	<	static final int maxUntimedSpins = maxTimedSpins * 32;
930	>	private String stateToString(long s) {
931	>	return super.toString() +
932	>	"[phase = " + phaseOf(s) +
933	>	" parties = " + partiesOf(s) +
934	>	" arrived = " + arrivedOf(s) + "]";
935	>	}
936
937	<	/**
746	<	* The number of nanoseconds for which it is faster to spin
747	<	* rather than to use timed park. A rough estimate suffices.
748	<	*/
749	<	static final long spinForTimeoutThreshold = 1000L;
937	>	// Waiting mechanics
938
939		/**
940	<	* Wait nodes for Treiber stack representing wait queue for non-FJ
753	<	* tasks.
940	>	* Removes and signals threads from queue for phase.
941		*/
942	<	static final class QNode {
943	<	QNode next;
944	<	volatile Thread thread; // nulled to cancel wait
945	<	QNode() {
946	<	thread = Thread.currentThread();
947	<	}
948	<	void signal() {
949	<	Thread t = thread;
950	<	if (t != null) {
764	<	thread = null;
942	>	private void releaseWaiters(int phase) {
943	>	QNode q;   // first element of queue
944	>	Thread t;  // its thread
945	>	AtomicReference<QNode> head = (phase & 1) == 0 ? evenQ : oddQ;
946	>	while ((q = head.get()) != null &&
947	>	q.phase != (int)(root.state >>> PHASE_SHIFT)) {
948	>	if (head.compareAndSet(q, q.next) &&
949	>	(t = q.thread) != null) {
950	>	q.thread = null;
951		LockSupport.unpark(t);
952		}
953		}
954		}
955
956		/**
957	<	* Removes and signals waiting threads from wait queue
957	>	* Variant of releaseWaiters that additionally tries to remove any
958	>	* nodes no longer waiting for advance due to timeout or
959	>	* interrupt. Currently, nodes are removed only if they are at
960	>	* head of queue, which suffices to reduce memory footprint in
961	>	* most usages.
962	>	*
963	>	* @return current phase on exit
964		*/
965	<	private void releaseWaiters(int phase) {
966	<	AtomicReference<QNode> head = queueFor(phase);
967	<	QNode q;
968	<	while ((q = head.get()) != null) {
969	<	if (head.compareAndSet(q, q.next))
970	<	q.signal();
965	>	private int abortWait(int phase) {
966	>	AtomicReference<QNode> head = (phase & 1) == 0 ? evenQ : oddQ;
967	>	for (;;) {
968	>	Thread t;
969	>	QNode q = head.get();
970	>	int p = (int)(root.state >>> PHASE_SHIFT);
971	>	if (q == null || ((t = q.thread) != null && q.phase == p))
972	>	return p;
973	>	if (head.compareAndSet(q, q.next) && t != null) {
974	>	q.thread = null;
975	>	LockSupport.unpark(t);
976	>	}
977		}
978		}
979
980	+	/** The number of CPUs, for spin control */
981	+	private static final int NCPU = Runtime.getRuntime().availableProcessors();
982	+
983		/**
984	<	* Enqueues node and waits unless aborted or signalled.
984	>	* The number of times to spin before blocking while waiting for
985	>	* advance, per arrival while waiting. On multiprocessors, fully
986	>	* blocking and waking up a large number of threads all at once is
987	>	* usually a very slow process, so we use rechargeable spins to
988	>	* avoid it when threads regularly arrive: When a thread in
989	>	* internalAwaitAdvance notices another arrival before blocking,
990	>	* and there appear to be enough CPUs available, it spins
991	>	* SPINS_PER_ARRIVAL more times before blocking. The value trades
992	>	* off good-citizenship vs big unnecessary slowdowns.
993		*/
994	<	private int untimedWait(int phase) {
786	<	int spins = maxUntimedSpins;
787	<	QNode node = null;
788	<	boolean interrupted = false;
789	<	boolean queued = false;
790	<	int p;
791	<	while ((p = getPhase()) == phase) {
792	<	interrupted = Thread.interrupted();
793	<	if (node != null) {
794	<	if (!queued) {
795	<	AtomicReference<QNode> head = queueFor(phase);
796	<	queued = head.compareAndSet(node.next = head.get(), node);
797	<	}
798	<	else if (node.thread != null)
799	<	LockSupport.park(this);
800	<	}
801	<	else if (spins <= 0)
802	<	node = new QNode();
803	<	else
804	<	--spins;
805	<	}
806	<	if (node != null)
807	<	node.thread = null;
808	<	if (interrupted)
809	<	Thread.currentThread().interrupt();
810	<	releaseWaiters(phase);
811	<	return p;
812	<	}
994	>	static final int SPINS_PER_ARRIVAL = (NCPU < 2) ? 1 : 1 << 8;
995
996		/**
997	<	* Messier interruptible version
998	<	*/
999	<	private int interruptibleWait(int phase) throws InterruptedException {
1000	<	int spins = maxUntimedSpins;
1001	<	QNode node = null;
1002	<	boolean queued = false;
1003	<	boolean interrupted = false;
997	>	* Possibly blocks and waits for phase to advance unless aborted.
998	>	* Call only from root node.
999	>	*
1000	>	* @param phase current phase
1001	>	* @param node if non-null, the wait node to track interrupt and timeout;
1002	>	* if null, denotes noninterruptible wait
1003	>	* @return current phase
1004	>	*/
1005	>	private int internalAwaitAdvance(int phase, QNode node) {
1006	>	releaseWaiters(phase-1);          // ensure old queue clean
1007	>	boolean queued = false;           // true when node is enqueued
1008	>	int lastUnarrived = 0;            // to increase spins upon change
1009	>	int spins = SPINS_PER_ARRIVAL;
1010	>	long s;
1011		int p;
1012	<	while ((p = getPhase()) == phase) {
1013	<	if (interrupted = Thread.interrupted())
1012	>	while ((p = (int)((s = state) >>> PHASE_SHIFT)) == phase) {
1013	>	if (node == null) {           // spinning in noninterruptible mode
1014	>	int unarrived = (int)s & UNARRIVED_MASK;
1015	>	if (unarrived != lastUnarrived &&
1016	>	(lastUnarrived = unarrived) < NCPU)
1017	>	spins += SPINS_PER_ARRIVAL;
1018	>	boolean interrupted = Thread.interrupted();
1019	>	if (interrupted || --spins < 0) { // need node to record intr
1020	>	node = new QNode(this, phase, false, false, 0L);
1021	>	node.wasInterrupted = interrupted;
1022	>	}
1023	>	}
1024	>	else if (node.isReleasable()) // done or aborted
1025		break;
1026	<	if (node != null) {
1027	<	if (!queued) {
1028	<	AtomicReference<QNode> head = queueFor(phase);
1029	<	queued = head.compareAndSet(node.next = head.get(), node);
1026	>	else if (!queued) {           // push onto queue
1027	>	AtomicReference<QNode> head = (phase & 1) == 0 ? evenQ : oddQ;
1028	>	QNode q = node.next = head.get();
1029	>	if ((q == null || q.phase == phase) &&
1030	>	(int)(state >>> PHASE_SHIFT) == phase) // avoid stale enq
1031	>	queued = head.compareAndSet(q, node);
1032	>	}
1033	>	else {
1034	>	try {
1035	>	ForkJoinPool.managedBlock(node);
1036	>	} catch (InterruptedException ie) {
1037	>	node.wasInterrupted = true;
1038		}
831	–	else if (node.thread != null)
832	–	LockSupport.park(this);
1039		}
1040	<	else if (spins <= 0)
1041	<	node = new QNode();
1042	<	else
1043	<	--spins;
1044	<	}
1045	<	if (node != null)
1046	<	node.thread = null;
1047	<	if (interrupted)
1048	<	throw new InterruptedException();
1040	>	}
1041	>
1042	>	if (node != null) {
1043	>	if (node.thread != null)
1044	>	node.thread = null;       // avoid need for unpark()
1045	>	if (node.wasInterrupted && !node.interruptible)
1046	>	Thread.currentThread().interrupt();
1047	>	if (p == phase && (p = (int)(state >>> PHASE_SHIFT)) == phase)
1048	>	return abortWait(phase); // possibly clean up on abort
1049	>	}
1050		releaseWaiters(phase);
1051		return p;
1052		}
1053
1054		/**
1055	<	* Even messier timeout version.
1055	>	* Wait nodes for Treiber stack representing wait queue
1056		*/
1057	<	private int timedWait(int phase, long nanos)
1058	<	throws InterruptedException, TimeoutException {
1059	<	int p;
1060	<	if ((p = getPhase()) == phase) {
1061	<	long lastTime = System.nanoTime();
1062	<	int spins = maxTimedSpins;
1063	<	QNode node = null;
1064	<	boolean queued = false;
1065	<	boolean interrupted = false;
1066	<	while ((p = getPhase()) == phase) {
1067	<	if (interrupted = Thread.interrupted())
1068	<	break;
1069	<	long now = System.nanoTime();
1070	<	if ((nanos -= now - lastTime) <= 0)
1071	<	break;
1072	<	lastTime = now;
1073	<	if (node != null) {
1074	<	if (!queued) {
1075	<	AtomicReference<QNode> head = queueFor(phase);
1076	<	queued = head.compareAndSet(node.next = head.get(), node);
1077	<	}
1078	<	else if (node.thread != null &&
1079	<	nanos > spinForTimeoutThreshold) {
1080	<	LockSupport.parkNanos(this, nanos);
1081	<	}
1057	>	static final class QNode implements ForkJoinPool.ManagedBlocker {
1058	>	final Phaser phaser;
1059	>	final int phase;
1060	>	final boolean interruptible;
1061	>	final boolean timed;
1062	>	boolean wasInterrupted;
1063	>	long nanos;
1064	>	long lastTime;
1065	>	volatile Thread thread; // nulled to cancel wait
1066	>	QNode next;
1067	>
1068	>	QNode(Phaser phaser, int phase, boolean interruptible,
1069	>	boolean timed, long nanos) {
1070	>	this.phaser = phaser;
1071	>	this.phase = phase;
1072	>	this.interruptible = interruptible;
1073	>	this.nanos = nanos;
1074	>	this.timed = timed;
1075	>	this.lastTime = timed ? System.nanoTime() : 0L;
1076	>	thread = Thread.currentThread();
1077	>	}
1078	>
1079	>	public boolean isReleasable() {
1080	>	if (thread == null)
1081	>	return true;
1082	>	if (phaser.getPhase() != phase) {
1083	>	thread = null;
1084	>	return true;
1085	>	}
1086	>	if (Thread.interrupted())
1087	>	wasInterrupted = true;
1088	>	if (wasInterrupted && interruptible) {
1089	>	thread = null;
1090	>	return true;
1091	>	}
1092	>	if (timed) {
1093	>	if (nanos > 0L) {
1094	>	long now = System.nanoTime();
1095	>	nanos -= now - lastTime;
1096	>	lastTime = now;
1097	>	}
1098	>	if (nanos <= 0L) {
1099	>	thread = null;
1100	>	return true;
1101		}
876	–	else if (spins <= 0)
877	–	node = new QNode();
878	–	else
879	–	--spins;
1102		}
1103	<	if (node != null)
882	<	node.thread = null;
883	<	if (interrupted)
884	<	throw new InterruptedException();
885	<	if (p == phase && (p = getPhase()) == phase)
886	<	throw new TimeoutException();
1103	>	return false;
1104		}
888	–	releaseWaiters(phase);
889	–	return p;
890	–	}
1105
1106	<	// Temporary Unsafe mechanics for preliminary release
1106	>	public boolean block() {
1107	>	if (isReleasable())
1108	>	return true;
1109	>	else if (!timed)
1110	>	LockSupport.park(this);
1111	>	else if (nanos > 0)
1112	>	LockSupport.parkNanos(this, nanos);
1113	>	return isReleasable();
1114	>	}
1115	>	}
1116
1117	<	static final Unsafe _unsafe;
895	<	static final long stateOffset;
1117	>	// Unsafe mechanics
1118
1119	+	private static final sun.misc.Unsafe UNSAFE;
1120	+	private static final long stateOffset;
1121		static {
1122		try {
1123	<	if (Phaser.class.getClassLoader() != null) {
1124	<	Field f = Unsafe.class.getDeclaredField("theUnsafe");
1125	<	f.setAccessible(true);
1126	<	_unsafe = (Unsafe)f.get(null);
903	<	}
904	<	else
905	<	_unsafe = Unsafe.getUnsafe();
906	<	stateOffset = _unsafe.objectFieldOffset
907	<	(Phaser.class.getDeclaredField("state"));
1123	>	UNSAFE = getUnsafe();
1124	>	Class<?> k = Phaser.class;
1125	>	stateOffset = UNSAFE.objectFieldOffset
1126	>	(k.getDeclaredField("state"));
1127		} catch (Exception e) {
1128	<	throw new RuntimeException("Could not initialize intrinsics", e);
1128	>	throw new Error(e);
1129		}
1130		}
1131
1132	<	final boolean casState(long cmp, long val) {
1133	<	return _unsafe.compareAndSwapLong(this, stateOffset, cmp, val);
1132	>	/**
1133	>	* Returns a sun.misc.Unsafe.  Suitable for use in a 3rd party package.
1134	>	* Replace with a simple call to Unsafe.getUnsafe when integrating
1135	>	* into a jdk.
1136	>	*
1137	>	* @return a sun.misc.Unsafe
1138	>	*/
1139	>	private static sun.misc.Unsafe getUnsafe() {
1140	>	try {
1141	>	return sun.misc.Unsafe.getUnsafe();
1142	>	} catch (SecurityException se) {
1143	>	try {
1144	>	return java.security.AccessController.doPrivileged
1145	>	(new java.security
1146	>	.PrivilegedExceptionAction<sun.misc.Unsafe>() {
1147	>	public sun.misc.Unsafe run() throws Exception {
1148	>	java.lang.reflect.Field f = sun.misc
1149	>	.Unsafe.class.getDeclaredField("theUnsafe");
1150	>	f.setAccessible(true);
1151	>	return (sun.misc.Unsafe) f.get(null);
1152	>	}});
1153	>	} catch (java.security.PrivilegedActionException e) {
1154	>	throw new RuntimeException("Could not initialize intrinsics",
1155	>	e.getCause());
1156	>	}
1157	>	}
1158		}
1159		}

Diff Legend

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