test/tck/LockSupportTest.java

/*
 * Written by Doug Lea and Martin Buchholz with assistance from
 * members of JCP JSR-166 Expert Group and released to the public
 * domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 * Other contributors include Andrew Wright, Jeffrey Hayes,
 * Pat Fisher, Mike Judd.
 */

import static java.util.concurrent.TimeUnit.MILLISECONDS;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.locks.LockSupport;

import junit.framework.Test;
import junit.framework.TestSuite;

public class LockSupportTest extends JSR166TestCase {
    public static void main(String[] args) {
        main(suite(), args);
    }

    public static Test suite() {
        return new TestSuite(LockSupportTest.class);
    }

    static {
        // Reduce the risk of rare disastrous classloading in first call to
        // LockSupport.park: https://bugs.openjdk.java.net/browse/JDK-8074773
        Class<?> ensureLoaded = LockSupport.class;
    }

    /**
     * Returns the blocker object used by tests in this file.
     * Any old object will do; we'll return a convenient one.
     */
    static Object theBlocker() {
        return LockSupportTest.class;
    }

    enum ParkMethod {
        park() {
            void park() {
                LockSupport.park();
            }
            Thread.State parkedState() { return Thread.State.WAITING; }
        },
        parkUntil() {
            void park(long millis) {
                LockSupport.parkUntil(deadline(millis));
            }
        },
        parkNanos() {
            void park(long millis) {
                LockSupport.parkNanos(MILLISECONDS.toNanos(millis));
            }
        },
        parkBlocker() {
            void park() {
                LockSupport.park(theBlocker());
            }
            Thread.State parkedState() { return Thread.State.WAITING; }
        },
        parkUntilBlocker() {
            void park(long millis) {
                LockSupport.parkUntil(theBlocker(), deadline(millis));
            }
        },
        parkNanosBlocker() {
            void park(long millis) {
                LockSupport.parkNanos(theBlocker(),
                                      MILLISECONDS.toNanos(millis));
            }
        };

        void park() { park(2 * LONG_DELAY_MS); }
        void park(long millis) {
            throw new UnsupportedOperationException();
        }
        Thread.State parkedState() { return Thread.State.TIMED_WAITING; }

        /** Returns a deadline to use with parkUntil. */
        long deadline(long millis) {
            // beware of rounding
            return System.currentTimeMillis() + millis + 1;
        }
    }

    /**
     * park is released by subsequent unpark
     */
    public void testParkBeforeUnpark_park() {
        testParkBeforeUnpark(ParkMethod.park);
    }
    public void testParkBeforeUnpark_parkNanos() {
        testParkBeforeUnpark(ParkMethod.parkNanos);
    }
    public void testParkBeforeUnpark_parkUntil() {
        testParkBeforeUnpark(ParkMethod.parkUntil);
    }
    public void testParkBeforeUnpark_parkBlocker() {
        testParkBeforeUnpark(ParkMethod.parkBlocker);
    }
    public void testParkBeforeUnpark_parkNanosBlocker() {
        testParkBeforeUnpark(ParkMethod.parkNanosBlocker);
    }
    public void testParkBeforeUnpark_parkUntilBlocker() {
        testParkBeforeUnpark(ParkMethod.parkUntilBlocker);
    }
    public void testParkBeforeUnpark(final ParkMethod parkMethod) {
        final CountDownLatch pleaseUnpark = new CountDownLatch(1);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() {
                pleaseUnpark.countDown();
                parkMethod.park();
            }});

        await(pleaseUnpark);
        LockSupport.unpark(t);
        awaitTermination(t);
    }

    /**
     * park is released by preceding unpark
     */
    public void testParkAfterUnpark_park() {
        testParkAfterUnpark(ParkMethod.park);
    }
    public void testParkAfterUnpark_parkNanos() {
        testParkAfterUnpark(ParkMethod.parkNanos);
    }
    public void testParkAfterUnpark_parkUntil() {
        testParkAfterUnpark(ParkMethod.parkUntil);
    }
    public void testParkAfterUnpark_parkBlocker() {
        testParkAfterUnpark(ParkMethod.parkBlocker);
    }
    public void testParkAfterUnpark_parkNanosBlocker() {
        testParkAfterUnpark(ParkMethod.parkNanosBlocker);
    }
    public void testParkAfterUnpark_parkUntilBlocker() {
        testParkAfterUnpark(ParkMethod.parkUntilBlocker);
    }
    public void testParkAfterUnpark(final ParkMethod parkMethod) {
        final CountDownLatch pleaseUnpark = new CountDownLatch(1);
        final AtomicBoolean pleasePark = new AtomicBoolean(false);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() {
                pleaseUnpark.countDown();
                while (!pleasePark.get())
                    Thread.yield();
                parkMethod.park();
            }});

        await(pleaseUnpark);
        LockSupport.unpark(t);
        pleasePark.set(true);
        awaitTermination(t);
    }

    /**
     * park is released by subsequent interrupt
     */
    public void testParkBeforeInterrupt_park() {
        testParkBeforeInterrupt(ParkMethod.park);
    }
    public void testParkBeforeInterrupt_parkNanos() {
        testParkBeforeInterrupt(ParkMethod.parkNanos);
    }
    public void testParkBeforeInterrupt_parkUntil() {
        testParkBeforeInterrupt(ParkMethod.parkUntil);
    }
    public void testParkBeforeInterrupt_parkBlocker() {
        testParkBeforeInterrupt(ParkMethod.parkBlocker);
    }
    public void testParkBeforeInterrupt_parkNanosBlocker() {
        testParkBeforeInterrupt(ParkMethod.parkNanosBlocker);
    }
    public void testParkBeforeInterrupt_parkUntilBlocker() {
        testParkBeforeInterrupt(ParkMethod.parkUntilBlocker);
    }
    public void testParkBeforeInterrupt(final ParkMethod parkMethod) {
        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() {
                pleaseInterrupt.countDown();
                for (int tries = MAX_SPURIOUS_WAKEUPS; tries-->0; ) {
                    parkMethod.park();
                    if (Thread.interrupted())
                        return;
                }
                fail("too many consecutive spurious wakeups?");
            }});

        await(pleaseInterrupt);
        assertThreadBlocks(t, parkMethod.parkedState());
        t.interrupt();
        awaitTermination(t);
    }

    /**
     * park is released by preceding interrupt
     */
    public void testParkAfterInterrupt_park() {
        testParkAfterInterrupt(ParkMethod.park);
    }
    public void testParkAfterInterrupt_parkNanos() {
        testParkAfterInterrupt(ParkMethod.parkNanos);
    }
    public void testParkAfterInterrupt_parkUntil() {
        testParkAfterInterrupt(ParkMethod.parkUntil);
    }
    public void testParkAfterInterrupt_parkBlocker() {
        testParkAfterInterrupt(ParkMethod.parkBlocker);
    }
    public void testParkAfterInterrupt_parkNanosBlocker() {
        testParkAfterInterrupt(ParkMethod.parkNanosBlocker);
    }
    public void testParkAfterInterrupt_parkUntilBlocker() {
        testParkAfterInterrupt(ParkMethod.parkUntilBlocker);
    }
    public void testParkAfterInterrupt(final ParkMethod parkMethod) {
        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() throws Exception {
                pleaseInterrupt.countDown();
                while (!Thread.currentThread().isInterrupted())
                    Thread.yield();
                parkMethod.park();
                assertTrue(Thread.interrupted());
            }});

        await(pleaseInterrupt);
        t.interrupt();
        awaitTermination(t);
    }

    /**
     * timed park times out if not unparked
     */
    public void testParkTimesOut_parkNanos() {
        testParkTimesOut(ParkMethod.parkNanos);
    }
    public void testParkTimesOut_parkUntil() {
        testParkTimesOut(ParkMethod.parkUntil);
    }
    public void testParkTimesOut_parkNanosBlocker() {
        testParkTimesOut(ParkMethod.parkNanosBlocker);
    }
    public void testParkTimesOut_parkUntilBlocker() {
        testParkTimesOut(ParkMethod.parkUntilBlocker);
    }
    public void testParkTimesOut(final ParkMethod parkMethod) {
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() {
                for (int tries = MAX_SPURIOUS_WAKEUPS; tries-->0; ) {
                    long startTime = System.nanoTime();
                    parkMethod.park(timeoutMillis());
                    if (millisElapsedSince(startTime) >= timeoutMillis())
                        return;
                }
                fail("too many consecutive spurious wakeups?");
            }});

        awaitTermination(t);
    }

    /**
     * getBlocker(null) throws NullPointerException
     */
    public void testGetBlockerNull() {
        try {
            LockSupport.getBlocker(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * getBlocker returns the blocker object passed to park
     */
    public void testGetBlocker_parkBlocker() {
        testGetBlocker(ParkMethod.parkBlocker);
    }
    public void testGetBlocker_parkNanosBlocker() {
        testGetBlocker(ParkMethod.parkNanosBlocker);
    }
    public void testGetBlocker_parkUntilBlocker() {
        testGetBlocker(ParkMethod.parkUntilBlocker);
    }
    public void testGetBlocker(final ParkMethod parkMethod) {
        final CountDownLatch started = new CountDownLatch(1);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() {
                Thread t = Thread.currentThread();
                started.countDown();
                for (int tries = MAX_SPURIOUS_WAKEUPS; tries-->0; ) {
                    assertNull(LockSupport.getBlocker(t));
                    parkMethod.park();
                    assertNull(LockSupport.getBlocker(t));
                    if (Thread.interrupted())
                        return;
                }
                fail("too many consecutive spurious wakeups?");
            }});

        long startTime = System.nanoTime();
        await(started);
        for (;;) {
            Object x = LockSupport.getBlocker(t);
            if (x == theBlocker()) { // success
                t.interrupt();
                awaitTermination(t);
                assertNull(LockSupport.getBlocker(t));
                return;
            } else {
                assertNull(x);  // ok
                if (millisElapsedSince(startTime) > LONG_DELAY_MS)
                    fail("timed out");
                if (t.getState() == Thread.State.TERMINATED)
                    break;
                Thread.yield();
            }
        }
    }

    /**
     * timed park(0) returns immediately.
     *
     * Requires hotspot fix for:
     * 6763959 java.util.concurrent.locks.LockSupport.parkUntil(0) blocks forever
     * which is in jdk7-b118 and 6u25.
     */
    public void testPark0_parkNanos() {
        testPark0(ParkMethod.parkNanos);
    }
    public void testPark0_parkUntil() {
        testPark0(ParkMethod.parkUntil);
    }
    public void testPark0_parkNanosBlocker() {
        testPark0(ParkMethod.parkNanosBlocker);
    }
    public void testPark0_parkUntilBlocker() {
        testPark0(ParkMethod.parkUntilBlocker);
    }
    public void testPark0(final ParkMethod parkMethod) {
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() {
                parkMethod.park(0L);
            }});

        awaitTermination(t);
    }

    /**
     * timed park(Long.MIN_VALUE) returns immediately.
     */
    public void testParkNeg_parkNanos() {
        testParkNeg(ParkMethod.parkNanos);
    }
    public void testParkNeg_parkUntil() {
        testParkNeg(ParkMethod.parkUntil);
    }
    public void testParkNeg_parkNanosBlocker() {
        testParkNeg(ParkMethod.parkNanosBlocker);
    }
    public void testParkNeg_parkUntilBlocker() {
        testParkNeg(ParkMethod.parkUntilBlocker);
    }
    public void testParkNeg(final ParkMethod parkMethod) {
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() {
                parkMethod.park(Long.MIN_VALUE);
            }});

        awaitTermination(t);
    }
}
Revision:	1.31
Committed:	Sat May 13 23:50:00 2017 UTC (6 years, 11 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.30:	+7 -8 lines
Log Message:	claw back some millis using assertThreadBlocks
#	User	Rev	Content
1	dl	1.1	/*
2	jsr166	1.15	* Written by Doug Lea and Martin Buchholz with assistance from
3			* members of JCP JSR-166 Expert Group and released to the public
4			* domain, as explained at
5	jsr166	1.18	* http://creativecommons.org/publicdomain/zero/1.0/
6	jsr166	1.8	* Other contributors include Andrew Wright, Jeffrey Hayes,
7			* Pat Fisher, Mike Judd.
8	dl	1.1	*/
9
10	jsr166	1.24	import static java.util.concurrent.TimeUnit.MILLISECONDS;
11
12	jsr166	1.23	import java.util.concurrent.CountDownLatch;
13	jsr166	1.15	import java.util.concurrent.atomic.AtomicBoolean;
14	jsr166	1.23	import java.util.concurrent.locks.LockSupport;
15	jsr166	1.24
16			import junit.framework.Test;
17			import junit.framework.TestSuite;
18	dl	1.1
19	jsr166	1.10	public class LockSupportTest extends JSR166TestCase {
20	dl	1.1	public static void main(String[] args) {
21	jsr166	1.25	main(suite(), args);
22	dl	1.1	}
23	jsr166	1.15
24	dl	1.1	public static Test suite() {
25	jsr166	1.12	return new TestSuite(LockSupportTest.class);
26	dl	1.1	}
27
28	jsr166	1.26	static {
29			// Reduce the risk of rare disastrous classloading in first call to
30			// LockSupport.park: https://bugs.openjdk.java.net/browse/JDK-8074773
31			Class<?> ensureLoaded = LockSupport.class;
32			}
33
34	dl	1.3	/**
35	jsr166	1.23	* Returns the blocker object used by tests in this file.
36			* Any old object will do; we'll return a convenient one.
37	dl	1.3	*/
38	jsr166	1.23	static Object theBlocker() {
39			return LockSupportTest.class;
40			}
41
42			enum ParkMethod {
43			park() {
44			void park() {
45	jsr166	1.11	LockSupport.park();
46	jsr166	1.23	}
47	jsr166	1.31	Thread.State parkedState() { return Thread.State.WAITING; }
48	jsr166	1.23	},
49			parkUntil() {
50			void park(long millis) {
51			LockSupport.parkUntil(deadline(millis));
52			}
53			},
54			parkNanos() {
55			void park(long millis) {
56			LockSupport.parkNanos(MILLISECONDS.toNanos(millis));
57			}
58			},
59			parkBlocker() {
60			void park() {
61			LockSupport.park(theBlocker());
62			}
63	jsr166	1.31	Thread.State parkedState() { return Thread.State.WAITING; }
64	jsr166	1.23	},
65			parkUntilBlocker() {
66			void park(long millis) {
67			LockSupport.parkUntil(theBlocker(), deadline(millis));
68			}
69			},
70			parkNanosBlocker() {
71			void park(long millis) {
72			LockSupport.parkNanos(theBlocker(),
73			MILLISECONDS.toNanos(millis));
74			}
75			};
76
77			void park() { park(2 * LONG_DELAY_MS); }
78	jsr166	1.31	void park(long millis) {
79			throw new UnsupportedOperationException();
80			}
81			Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
82	jsr166	1.23
83			/** Returns a deadline to use with parkUntil. */
84			long deadline(long millis) {
85			// beware of rounding
86			return System.currentTimeMillis() + millis + 1;
87			}
88	jsr166	1.15	}
89
90			/**
91	jsr166	1.23	* park is released by subsequent unpark
92	jsr166	1.15	*/
93	jsr166	1.23	public void testParkBeforeUnpark_park() {
94			testParkBeforeUnpark(ParkMethod.park);
95			}
96			public void testParkBeforeUnpark_parkNanos() {
97			testParkBeforeUnpark(ParkMethod.parkNanos);
98			}
99			public void testParkBeforeUnpark_parkUntil() {
100			testParkBeforeUnpark(ParkMethod.parkUntil);
101			}
102			public void testParkBeforeUnpark_parkBlocker() {
103			testParkBeforeUnpark(ParkMethod.parkBlocker);
104			}
105			public void testParkBeforeUnpark_parkNanosBlocker() {
106			testParkBeforeUnpark(ParkMethod.parkNanosBlocker);
107			}
108			public void testParkBeforeUnpark_parkUntilBlocker() {
109			testParkBeforeUnpark(ParkMethod.parkUntilBlocker);
110	jsr166	1.15	}
111	jsr166	1.23	public void testParkBeforeUnpark(final ParkMethod parkMethod) {
112			final CountDownLatch pleaseUnpark = new CountDownLatch(1);
113	jsr166	1.16	Thread t = newStartedThread(new CheckedRunnable() {
114	jsr166	1.15	public void realRun() {
115	jsr166	1.23	pleaseUnpark.countDown();
116			parkMethod.park();
117	jsr166	1.15	}});
118
119	jsr166	1.23	await(pleaseUnpark);
120	jsr166	1.11	LockSupport.unpark(t);
121	jsr166	1.23	awaitTermination(t);
122	dl	1.1	}
123
124	dl	1.3	/**
125	jsr166	1.15	* park is released by preceding unpark
126	dl	1.4	*/
127	jsr166	1.23	public void testParkAfterUnpark_park() {
128			testParkAfterUnpark(ParkMethod.park);
129			}
130			public void testParkAfterUnpark_parkNanos() {
131			testParkAfterUnpark(ParkMethod.parkNanos);
132			}
133			public void testParkAfterUnpark_parkUntil() {
134			testParkAfterUnpark(ParkMethod.parkUntil);
135			}
136			public void testParkAfterUnpark_parkBlocker() {
137			testParkAfterUnpark(ParkMethod.parkBlocker);
138			}
139			public void testParkAfterUnpark_parkNanosBlocker() {
140			testParkAfterUnpark(ParkMethod.parkNanosBlocker);
141	dl	1.4	}
142	jsr166	1.23	public void testParkAfterUnpark_parkUntilBlocker() {
143			testParkAfterUnpark(ParkMethod.parkUntilBlocker);
144	jsr166	1.15	}
145	jsr166	1.23	public void testParkAfterUnpark(final ParkMethod parkMethod) {
146			final CountDownLatch pleaseUnpark = new CountDownLatch(1);
147			final AtomicBoolean pleasePark = new AtomicBoolean(false);
148	jsr166	1.16	Thread t = newStartedThread(new CheckedRunnable() {
149	jsr166	1.23	public void realRun() {
150			pleaseUnpark.countDown();
151			while (!pleasePark.get())
152	jsr166	1.15	Thread.yield();
153	jsr166	1.23	parkMethod.park();
154	jsr166	1.15	}});
155
156	jsr166	1.23	await(pleaseUnpark);
157	jsr166	1.15	LockSupport.unpark(t);
158	jsr166	1.23	pleasePark.set(true);
159			awaitTermination(t);
160	jsr166	1.15	}
161
162			/**
163			* park is released by subsequent interrupt
164			*/
165	jsr166	1.23	public void testParkBeforeInterrupt_park() {
166			testParkBeforeInterrupt(ParkMethod.park);
167			}
168			public void testParkBeforeInterrupt_parkNanos() {
169			testParkBeforeInterrupt(ParkMethod.parkNanos);
170			}
171			public void testParkBeforeInterrupt_parkUntil() {
172			testParkBeforeInterrupt(ParkMethod.parkUntil);
173			}
174			public void testParkBeforeInterrupt_parkBlocker() {
175			testParkBeforeInterrupt(ParkMethod.parkBlocker);
176			}
177			public void testParkBeforeInterrupt_parkNanosBlocker() {
178			testParkBeforeInterrupt(ParkMethod.parkNanosBlocker);
179			}
180			public void testParkBeforeInterrupt_parkUntilBlocker() {
181			testParkBeforeInterrupt(ParkMethod.parkUntilBlocker);
182			}
183			public void testParkBeforeInterrupt(final ParkMethod parkMethod) {
184			final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
185	jsr166	1.16	Thread t = newStartedThread(new CheckedRunnable() {
186	jsr166	1.12	public void realRun() {
187	jsr166	1.23	pleaseInterrupt.countDown();
188	jsr166	1.29	for (int tries = MAX_SPURIOUS_WAKEUPS; tries-->0; ) {
189	jsr166	1.23	parkMethod.park();
190	jsr166	1.29	if (Thread.interrupted())
191			return;
192			}
193			fail("too many consecutive spurious wakeups?");
194	jsr166	1.15	}});
195
196	jsr166	1.23	await(pleaseInterrupt);
197	jsr166	1.31	assertThreadBlocks(t, parkMethod.parkedState());
198	jsr166	1.15	t.interrupt();
199	jsr166	1.23	awaitTermination(t);
200	jsr166	1.15	}
201
202			/**
203	jsr166	1.23	* park is released by preceding interrupt
204	jsr166	1.15	*/
205	jsr166	1.23	public void testParkAfterInterrupt_park() {
206			testParkAfterInterrupt(ParkMethod.park);
207			}
208			public void testParkAfterInterrupt_parkNanos() {
209			testParkAfterInterrupt(ParkMethod.parkNanos);
210			}
211			public void testParkAfterInterrupt_parkUntil() {
212			testParkAfterInterrupt(ParkMethod.parkUntil);
213			}
214			public void testParkAfterInterrupt_parkBlocker() {
215			testParkAfterInterrupt(ParkMethod.parkBlocker);
216			}
217			public void testParkAfterInterrupt_parkNanosBlocker() {
218			testParkAfterInterrupt(ParkMethod.parkNanosBlocker);
219	dl	1.4	}
220	jsr166	1.23	public void testParkAfterInterrupt_parkUntilBlocker() {
221			testParkAfterInterrupt(ParkMethod.parkUntilBlocker);
222	jsr166	1.15	}
223	jsr166	1.23	public void testParkAfterInterrupt(final ParkMethod parkMethod) {
224			final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
225	jsr166	1.16	Thread t = newStartedThread(new CheckedRunnable() {
226	jsr166	1.15	public void realRun() throws Exception {
227	jsr166	1.23	pleaseInterrupt.countDown();
228	jsr166	1.30	while (!Thread.currentThread().isInterrupted())
229	jsr166	1.15	Thread.yield();
230	jsr166	1.23	parkMethod.park();
231	jsr166	1.30	assertTrue(Thread.interrupted());
232	jsr166	1.15	}});
233
234	jsr166	1.23	await(pleaseInterrupt);
235	jsr166	1.15	t.interrupt();
236	jsr166	1.23	awaitTermination(t);
237	jsr166	1.15	}
238
239			/**
240	jsr166	1.23	* timed park times out if not unparked
241	jsr166	1.15	*/
242	jsr166	1.23	public void testParkTimesOut_parkNanos() {
243			testParkTimesOut(ParkMethod.parkNanos);
244			}
245			public void testParkTimesOut_parkUntil() {
246			testParkTimesOut(ParkMethod.parkUntil);
247			}
248			public void testParkTimesOut_parkNanosBlocker() {
249			testParkTimesOut(ParkMethod.parkNanosBlocker);
250			}
251			public void testParkTimesOut_parkUntilBlocker() {
252			testParkTimesOut(ParkMethod.parkUntilBlocker);
253			}
254			public void testParkTimesOut(final ParkMethod parkMethod) {
255	jsr166	1.16	Thread t = newStartedThread(new CheckedRunnable() {
256	jsr166	1.23	public void realRun() {
257	jsr166	1.27	for (int tries = MAX_SPURIOUS_WAKEUPS; tries-->0; ) {
258	jsr166	1.23	long startTime = System.nanoTime();
259			parkMethod.park(timeoutMillis());
260			if (millisElapsedSince(startTime) >= timeoutMillis())
261			return;
262			}
263	jsr166	1.27	fail("too many consecutive spurious wakeups?");
264	jsr166	1.15	}});
265
266	jsr166	1.23	awaitTermination(t);
267	jsr166	1.15	}
268
269			/**
270	jsr166	1.23	* getBlocker(null) throws NullPointerException
271	jsr166	1.15	*/
272	jsr166	1.23	public void testGetBlockerNull() {
273			try {
274			LockSupport.getBlocker(null);
275			shouldThrow();
276			} catch (NullPointerException success) {}
277	dl	1.4	}
278
279			/**
280	jsr166	1.23	* getBlocker returns the blocker object passed to park
281	dl	1.3	*/
282	jsr166	1.23	public void testGetBlocker_parkBlocker() {
283			testGetBlocker(ParkMethod.parkBlocker);
284			}
285			public void testGetBlocker_parkNanosBlocker() {
286			testGetBlocker(ParkMethod.parkNanosBlocker);
287			}
288			public void testGetBlocker_parkUntilBlocker() {
289			testGetBlocker(ParkMethod.parkUntilBlocker);
290			}
291			public void testGetBlocker(final ParkMethod parkMethod) {
292			final CountDownLatch started = new CountDownLatch(1);
293	jsr166	1.16	Thread t = newStartedThread(new CheckedRunnable() {
294	jsr166	1.12	public void realRun() {
295	jsr166	1.23	Thread t = Thread.currentThread();
296			started.countDown();
297	jsr166	1.29	for (int tries = MAX_SPURIOUS_WAKEUPS; tries-->0; ) {
298	jsr166	1.23	assertNull(LockSupport.getBlocker(t));
299			parkMethod.park();
300			assertNull(LockSupport.getBlocker(t));
301	jsr166	1.29	if (Thread.interrupted())
302			return;
303			}
304			fail("too many consecutive spurious wakeups?");
305	jsr166	1.11	}});
306
307	jsr166	1.23	long startTime = System.nanoTime();
308			await(started);
309			for (;;) {
310			Object x = LockSupport.getBlocker(t);
311			if (x == theBlocker()) { // success
312			t.interrupt();
313			awaitTermination(t);
314			assertNull(LockSupport.getBlocker(t));
315			return;
316			} else {
317			assertNull(x); // ok
318			if (millisElapsedSince(startTime) > LONG_DELAY_MS)
319			fail("timed out");
320	jsr166	1.29	if (t.getState() == Thread.State.TERMINATED)
321			break;
322	jsr166	1.23	Thread.yield();
323			}
324			}
325	dl	1.1	}
326
327	dl	1.3	/**
328	jsr166	1.23	* timed park(0) returns immediately.
329			*
330			* Requires hotspot fix for:
331			* 6763959 java.util.concurrent.locks.LockSupport.parkUntil(0) blocks forever
332			* which is in jdk7-b118 and 6u25.
333	dl	1.3	*/
334	jsr166	1.23	public void testPark0_parkNanos() {
335			testPark0(ParkMethod.parkNanos);
336			}
337			public void testPark0_parkUntil() {
338			testPark0(ParkMethod.parkUntil);
339			}
340			public void testPark0_parkNanosBlocker() {
341			testPark0(ParkMethod.parkNanosBlocker);
342			}
343			public void testPark0_parkUntilBlocker() {
344			testPark0(ParkMethod.parkUntilBlocker);
345			}
346			public void testPark0(final ParkMethod parkMethod) {
347	jsr166	1.16	Thread t = newStartedThread(new CheckedRunnable() {
348	jsr166	1.12	public void realRun() {
349	jsr166	1.23	parkMethod.park(0L);
350	jsr166	1.15	}});
351
352	jsr166	1.23	awaitTermination(t);
353	jsr166	1.15	}
354
355			/**
356	jsr166	1.23	* timed park(Long.MIN_VALUE) returns immediately.
357	jsr166	1.20	*/
358	jsr166	1.23	public void testParkNeg_parkNanos() {
359			testParkNeg(ParkMethod.parkNanos);
360			}
361			public void testParkNeg_parkUntil() {
362			testParkNeg(ParkMethod.parkUntil);
363			}
364			public void testParkNeg_parkNanosBlocker() {
365			testParkNeg(ParkMethod.parkNanosBlocker);
366			}
367			public void testParkNeg_parkUntilBlocker() {
368			testParkNeg(ParkMethod.parkUntilBlocker);
369	jsr166	1.20	}
370	jsr166	1.23	public void testParkNeg(final ParkMethod parkMethod) {
371	jsr166	1.16	Thread t = newStartedThread(new CheckedRunnable() {
372	jsr166	1.15	public void realRun() {
373	jsr166	1.23	parkMethod.park(Long.MIN_VALUE);
374	jsr166	1.11	}});
375
376	jsr166	1.21	awaitTermination(t);
377	dl	1.1	}
378			}