1 /*
2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
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 /**
25 * @test TestSmallHeap
26 * @bug 8067438
27 * @requires vm.gc=="null"
28 * @summary Verify that starting the VM with a small heap works
29 * @library /testlibrary
30 * @run main/othervm -Xmx4m -XX:+UseParallelGC TestSmallHeap
31 * @run main/othervm -Xmx4m -XX:+UseSerialGC TestSmallHeap
32 * @run main/othervm -Xmx4m -XX:+UseG1GC TestSmallHeap
33 * @run main/othervm -Xmx4m -XX:+UseConcMarkSweepGC -XX:CMSMarkStackSizeMax=1032 TestSmallHeap
34 *
35 * Note: It would be nice to verify the minimal supported heap size here,
36 * but that turns out to be quite tricky since we align the heap size based
37 * on the card table size. And the card table size is aligned based on the
38 * minimal pages size provided by the os. This means that on most platforms,
39 * where the minimal page size is 4k, we get a minimal heap size of 2m but
40 * on Solaris/Sparc we have a page size of 8k and get a minimal heap size
41 * of 8m.
42 * There is also no check in the VM for verifying that the maximum heap size
43 * is larger than the supported minimal heap size. This means that specifying
44 * -Xmx1m on the command line is fine but will give a heap of 2m (or 4m).
45 * To work around these rather strange behaviors this test uses 4m for all
46 * platforms.
47 */
48
49 import sun.management.ManagementFactoryHelper;
50 import static com.oracle.java.testlibrary.Asserts.*;
51
52 public class TestSmallHeap {
53
54 public static void main(String[] args) {
55 String maxHeap = ManagementFactoryHelper.getDiagnosticMXBean().getVMOption("MaxHeapSize").getValue();
56 String expectedMaxHeap = "4194304";
57 assertEQ(maxHeap, expectedMaxHeap);
58 }
59 }
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1 /*
2 * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
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 /**
25 * @test TestSmallHeap
26 * @bug 8067438
27 * @requires vm.gc=="null"
28 * @summary Verify that starting the VM with a small heap works
29 * @library /testlibrary /../../test/lib
30 * @build TestSmallHeap
31 * @run main ClassFileInstaller sun.hotspot.WhiteBox
32 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xmx2m -XX:+UseParallelGC TestSmallHeap
33 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xmx2m -XX:+UseSerialGC TestSmallHeap
34 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xmx2m -XX:+UseG1GC TestSmallHeap
35 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xmx2m -XX:+UseConcMarkSweepGC TestSmallHeap
36 *
37 * Note: It would be nice to verify the minimal supported heap size (2m) here,
38 * but we align the heap size based on the card table size. And the card table
39 * size is aligned based on the minimal pages size provided by the os. This
40 * means that on most platforms, where the minimal page size is 4k, we get a
41 * minimal heap size of 2m but on Solaris/Sparc we have a page size of 8k and
42 * get a minimal heap size of 4m. And on platforms where the page size is 64k
43 * we get a minimal heap size of 32m. We never use large pages for the card table.
44 *
45 * There is also no check in the VM for verifying that the maximum heap size
46 * is larger than the supported minimal heap size. This means that specifying
47 * -Xmx1m on the command line is fine but will give a heap of 2m (or 4m or 32m).
48 *
49 * To work around these rather strange behaviors this test uses -Xmx2m but then
50 * calculates what the expected heap size should be. The calculation is a
51 * simplified version of the code in the VM. We assume that the card table will
52 * use one page. Each byte in the card table corresponds to 512 bytes on the heap.
53 * So, the expected heap size is page_size * 512.
54 */
55
56 import com.oracle.java.testlibrary.*;
57 import static com.oracle.java.testlibrary.Asserts.*;
58 import sun.hotspot.WhiteBox;
59 import sun.management.ManagementFactoryHelper;
60
61 public class TestSmallHeap {
62
63 public static void main(String[] args) {
64 WhiteBox wb = WhiteBox.getWhiteBox();
65 int pageSize = wb.getVMPageSize();
66 int heapBytesPerCard = 512;
67 long expectedMaxHeap = pageSize * heapBytesPerCard;
68 String maxHeap = ManagementFactoryHelper.getDiagnosticMXBean().getVMOption("MaxHeapSize").getValue();
69 assertEQ(Long.parseLong(maxHeap), expectedMaxHeap);
70 }
71 }
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