util/HashMap/WhiteBoxResizeTest.java

/*
 * Copyright (c) 2018, Red Hat, Inc. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

import org.testng.annotations.Test;

import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.lang.invoke.VarHandle;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ThreadLocalRandom;
import java.util.function.Supplier;
import java.util.stream.IntStream;

import static java.util.stream.Collectors.toMap;
import static org.testng.Assert.assertEquals;
import static org.testng.Assert.assertNull;

/*
 * @test
 * @bug 8210280
 * @modules java.base/java.util:open
 * @summary White box tests for HashMap internals around table resize
 * @run testng WhiteBoxResizeTest
 * @key randomness
 */
public class WhiteBoxResizeTest {
    final ThreadLocalRandom rnd = ThreadLocalRandom.current();
    final MethodHandle TABLE_SIZE_FOR;
    final VarHandle THRESHOLD;
    final VarHandle TABLE;

    public WhiteBoxResizeTest() throws ReflectiveOperationException {
        Class<?> mClass = HashMap.class;
        String nodeClassName = mClass.getName() + "$Node";
        Class<?> nodeArrayClass = Class.forName("[L" + nodeClassName + ";");
        MethodHandles.Lookup lookup = MethodHandles.privateLookupIn(mClass, MethodHandles.lookup());
        TABLE = lookup.findVarHandle(mClass, "table", nodeArrayClass);
        this.TABLE_SIZE_FOR = lookup.findStatic(
                mClass, "tableSizeFor",
                MethodType.methodType(int.class, int.class));
        this.THRESHOLD = lookup.findVarHandle(mClass, "threshold", int.class);
    }

    int tableSizeFor(int n) {
        try {
            return (int) TABLE_SIZE_FOR.invoke(n);
        } catch (Throwable t) { throw new AssertionError(t); }
    }

    Object[] table(HashMap map) {
        try {
            return (Object[]) TABLE.get(map);
        } catch (Throwable t) { throw new AssertionError(t); }
    }

    int capacity(HashMap map) {
        return table(map).length;
    }

    @Test
    public void testTableSizeFor() {
        assertEquals(tableSizeFor(0), 1);
        assertEquals(tableSizeFor(1), 1);
        assertEquals(tableSizeFor(2), 2);
        assertEquals(tableSizeFor(3), 4);
        assertEquals(tableSizeFor(15), 16);
        assertEquals(tableSizeFor(16), 16);
        assertEquals(tableSizeFor(17), 32);
        int maxSize = 1 << 30;
        assertEquals(tableSizeFor(maxSize - 1), maxSize);
        assertEquals(tableSizeFor(maxSize), maxSize);
        assertEquals(tableSizeFor(maxSize + 1), maxSize);
        assertEquals(tableSizeFor(Integer.MAX_VALUE), maxSize);
    }

    @Test
    public void capacityTestDefaultConstructor() {
        capacityTestDefaultConstructor(new HashMap<>());
        capacityTestDefaultConstructor(new LinkedHashMap<>());
    }

    void capacityTestDefaultConstructor(HashMap<Integer, Integer> map) {
        assertNull(table(map));

        map.put(1, 1);
        assertEquals(capacity(map), 16); // default initial capacity

        map.putAll(IntStream.range(0, 64).boxed().collect(toMap(i -> i, i -> i)));
        assertEquals(capacity(map), 128);
    }

    @Test
    public void capacityTestInitialCapacity() {
        int initialCapacity = rnd.nextInt(2, 128);
        List<Supplier<HashMap<Integer, Integer>>> suppliers = List.of(
            () -> new HashMap<>(initialCapacity),
            () -> new HashMap<>(initialCapacity, 0.75f),
            () -> new LinkedHashMap<>(initialCapacity),
            () -> new LinkedHashMap<>(initialCapacity, 0.75f));

        for (Supplier<HashMap<Integer, Integer>> supplier : suppliers) {
            HashMap<Integer, Integer> map = supplier.get();
            assertNull(table(map));

            map.put(1, 1);
            assertEquals(capacity(map), tableSizeFor(initialCapacity));
        }
    }
}
Revision:	1.5
Committed:	Tue Jan 21 23:46:12 2020 UTC (4 years, 4 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.4:	+1 -0 lines
Log Message:	8237589: Fix copyright header formatting
#	User	Rev	Content
1	jsr166	1.1	/*
2			* Copyright (c) 2018, Red Hat, Inc. All rights reserved.
3	jsr166	1.5	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4	jsr166	1.1	*
5			* This code is free software; you can redistribute it and/or modify it
6			* under the terms of the GNU General Public License version 2 only, as
7			* published by the Free Software Foundation.
8			*
9			* This code is distributed in the hope that it will be useful, but WITHOUT
10			* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11			* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12			* version 2 for more details (a copy is included in the LICENSE file that
13			* accompanied this code).
14			*
15			* You should have received a copy of the GNU General Public License version
16			* 2 along with this work; if not, write to the Free Software Foundation,
17			* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18			*
19			* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20			* or visit www.oracle.com if you need additional information or have any
21			* questions.
22			*/
23
24			import org.testng.annotations.Test;
25
26			import java.lang.invoke.MethodHandle;
27			import java.lang.invoke.MethodHandles;
28			import java.lang.invoke.MethodType;
29			import java.lang.invoke.VarHandle;
30			import java.util.HashMap;
31	jsr166	1.2	import java.util.LinkedHashMap;
32			import java.util.List;
33	jsr166	1.1	import java.util.Map;
34	jsr166	1.2	import java.util.concurrent.ThreadLocalRandom;
35			import java.util.function.Supplier;
36	jsr166	1.1	import java.util.stream.IntStream;
37
38			import static java.util.stream.Collectors.toMap;
39			import static org.testng.Assert.assertEquals;
40			import static org.testng.Assert.assertNull;
41
42			/*
43			* @test
44			* @bug 8210280
45			* @modules java.base/java.util:open
46			* @summary White box tests for HashMap internals around table resize
47			* @run testng WhiteBoxResizeTest
48	jsr166	1.3	* @key randomness
49	jsr166	1.1	*/
50			public class WhiteBoxResizeTest {
51	jsr166	1.2	final ThreadLocalRandom rnd = ThreadLocalRandom.current();
52	jsr166	1.1	final MethodHandle TABLE_SIZE_FOR;
53			final VarHandle THRESHOLD;
54			final VarHandle TABLE;
55
56			public WhiteBoxResizeTest() throws ReflectiveOperationException {
57			Class<?> mClass = HashMap.class;
58			String nodeClassName = mClass.getName() + "$Node";
59			Class<?> nodeArrayClass = Class.forName("[L" + nodeClassName + ";");
60			MethodHandles.Lookup lookup = MethodHandles.privateLookupIn(mClass, MethodHandles.lookup());
61			TABLE = lookup.findVarHandle(mClass, "table", nodeArrayClass);
62			this.TABLE_SIZE_FOR = lookup.findStatic(
63			mClass, "tableSizeFor",
64			MethodType.methodType(int.class, int.class));
65			this.THRESHOLD = lookup.findVarHandle(mClass, "threshold", int.class);
66			}
67
68			int tableSizeFor(int n) {
69			try {
70			return (int) TABLE_SIZE_FOR.invoke(n);
71			} catch (Throwable t) { throw new AssertionError(t); }
72			}
73
74			Object[] table(HashMap map) {
75			try {
76			return (Object[]) TABLE.get(map);
77			} catch (Throwable t) { throw new AssertionError(t); }
78			}
79
80			int capacity(HashMap map) {
81			return table(map).length;
82			}
83
84			@Test
85			public void testTableSizeFor() {
86			assertEquals(tableSizeFor(0), 1);
87			assertEquals(tableSizeFor(1), 1);
88			assertEquals(tableSizeFor(2), 2);
89			assertEquals(tableSizeFor(3), 4);
90			assertEquals(tableSizeFor(15), 16);
91			assertEquals(tableSizeFor(16), 16);
92			assertEquals(tableSizeFor(17), 32);
93			int maxSize = 1 << 30;
94			assertEquals(tableSizeFor(maxSize - 1), maxSize);
95			assertEquals(tableSizeFor(maxSize), maxSize);
96			assertEquals(tableSizeFor(maxSize + 1), maxSize);
97			assertEquals(tableSizeFor(Integer.MAX_VALUE), maxSize);
98			}
99
100			@Test
101	jsr166	1.2	public void capacityTestDefaultConstructor() {
102			capacityTestDefaultConstructor(new HashMap<>());
103			capacityTestDefaultConstructor(new LinkedHashMap<>());
104			}
105
106			void capacityTestDefaultConstructor(HashMap<Integer, Integer> map) {
107	jsr166	1.1	assertNull(table(map));
108
109			map.put(1, 1);
110	jsr166	1.2	assertEquals(capacity(map), 16); // default initial capacity
111	jsr166	1.1
112			map.putAll(IntStream.range(0, 64).boxed().collect(toMap(i -> i, i -> i)));
113			assertEquals(capacity(map), 128);
114			}
115	jsr166	1.2
116			@Test
117			public void capacityTestInitialCapacity() {
118	jsr166	1.4	int initialCapacity = rnd.nextInt(2, 128);
119	jsr166	1.2	List<Supplier<HashMap<Integer, Integer>>> suppliers = List.of(
120			() -> new HashMap<>(initialCapacity),
121			() -> new HashMap<>(initialCapacity, 0.75f),
122			() -> new LinkedHashMap<>(initialCapacity),
123			() -> new LinkedHashMap<>(initialCapacity, 0.75f));
124
125			for (Supplier<HashMap<Integer, Integer>> supplier : suppliers) {
126			HashMap<Integer, Integer> map = supplier.get();
127			assertNull(table(map));
128
129			map.put(1, 1);
130			assertEquals(capacity(map), tableSizeFor(initialCapacity));
131			}
132			}
133	jsr166	1.1	}