8345119: Some java/foreign tests wrongly assume aligned memory

[merykitty]

Hi,

This patch resolves some issues I found that the tests wrongly assume sufficient alignment from the segment returned by Arena::allocate.

Please take a look and leave your reviews, thanks a lot.

---

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Issue

• JDK-8345119: Some java/foreign tests wrongly assume aligned memory (Bug - P4)

Reviewers

• Maurizio Cimadamore (@mcimadamore - Reviewer)
• Jorn Vernee (@JornVernee - Reviewer)

Reviewing

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[openjdk]

@merykitty This change now passes all automated pre-integration checks.

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After integration, the commit message for the final commit will be:

8345119: Some java/foreign tests wrongly assume aligned memory

Reviewed-by: mcimadamore, jvernee

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At the time when this comment was updated there had been 6 new commits pushed to the master branch:

• 880f9a7: 8344220: Remove calls to SecurityManager and doPrivileged in java.net.InetAddress and sun.net.util.IPAddressUtil after JEP 486 integration
• 9527586: 8345073: Remove SecurityManager checks from sun.awt.image classes
• 1e3a0fd: 8035271: Incorrect indentation of LineNumberTable/LocalVariableTable/Exception table/LocalVariableTypeTable/StackMapTable/RuntimeVisibleTypeAnnotations in verbose mode
• 0312694: 8344882: (bf) Temporary direct buffers should not count against the upper limit on direct buffer memory
• 75f3ec7: 8344766: AES/CTR slow at big payloads
• 35bd2f3: 8344555: SM cleanup - drop reflection filter of System.security field

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (d1ea3b69)

[JornVernee]

Why does this segment need to be aligned?

[merykitty]

Because the bufferHandle here iterates through all kinds of element types:

@DataProvider(name = "bufferHandleOps")
public static Object[][] bufferHandleOps() throws Throwable {
    return new Object[][]{
            { MethodHandles.byteBufferViewVarHandle(char[].class, ByteOrder.nativeOrder()) },
            { MethodHandles.byteBufferViewVarHandle(short[].class, ByteOrder.nativeOrder()) },
            { MethodHandles.byteBufferViewVarHandle(int[].class, ByteOrder.nativeOrder()) },
            { MethodHandles.byteBufferViewVarHandle(long[].class, ByteOrder.nativeOrder()) },
            { MethodHandles.byteBufferViewVarHandle(float[].class, ByteOrder.nativeOrder()) },
            { MethodHandles.byteBufferViewVarHandle(double[].class, ByteOrder.nativeOrder()) }

The test then does all kind of accesses on these:

static Map<MethodHandle, Object[]> varHandleMembers(ByteBuffer bb, VarHandle handle) {
    Map<MethodHandle, Object[]> members = new HashMap<>();
    for (VarHandle.AccessMode mode : VarHandle.AccessMode.values()) {
        Class<?>[] params = handle.accessModeType(mode).parameterArray();
        Object[] args = Stream.concat(Stream.of(bb), Stream.of(params).skip(1)
                .map(TestByteBuffer::defaultValue))
                .toArray();
        try {
            members.put(MethodHandles.varHandleInvoker(mode, handle.accessModeType(mode)), args);
        } catch (Throwable ex) {
            throw new AssertionError(ex);
        }
    }
    return members;
}

And for access other than plain get and set, the natural alignment is required.

[JornVernee]

Ok, thanks for the explanation.

[mcimadamore]

Looks good. Normally, what Arena::allocate does is to use malloc which will always align to 16 bytes in 64-bit systems, but it's good to make the tests more robust.

[merykitty]

@mcimadamore @JornVernee Thanks a lot for your reviews!
/integrate

[openjdk]

Going to push as commit ce9d543.
Since your change was applied there have been 14 commits pushed to the master branch:

• 1a07d54: 8343703: Symbol name cleanups after JEP 479
• a0df0a5: 8340731: Cleanup remaining IA64 references in hotspot code
• 8485cb1: 8344822: CDS BulkLoaderTest.java#dynamic fails with COH
• f51363e: 8344913: Improve -Xlog:cds+map+oop logging for Java mirrors
• cf5ee0b: 8342280: Deprecate for removal java.awt.AWTPermission
• 8ad0b2a: 8345001: java/awt/doc-files/FocusSpec.html has SecurityManager references
• f6d2990: 8344824: CDS dump crashes when member_method of a lambda proxy is null
• 15378a7: 8345126: [BACKOUT] JDK-8318127: align_up has potential overflow
• 880f9a7: 8344220: Remove calls to SecurityManager and doPrivileged in java.net.InetAddress and sun.net.util.IPAddressUtil after JEP 486 integration
• 9527586: 8345073: Remove SecurityManager checks from sun.awt.image classes
• ... and 4 more: https://git.openjdk.org/jdk/compare/a491564001724da07ecb7d2e4a070c4abbd92cf5...master

Your commit was automatically rebased without conflicts.

[openjdk]

@merykitty Pushed as commit ce9d543.

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