8385670: Incorrect warning: Unexpected gaps for Klass alignment

[iklam]

There were several bugs in the logging of the allocation gaps in the AOT cache. After UseCompactObjectHeader becomes the default, we quite often get spurious waring of unfilled gaps when dumping dynamic CDS archives:

$ java -Xlog:aot -cp HelloWorld.jar -XX:ArchiveClassesAtExit=hw.jsa HelloWorld
...
[0.060s][warning][aot] Unexpected 1 gaps (8 bytes) for Klass alignment
[0.060s][info   ][aot] Allocated 46 objects of 3608 bytes in gaps (remain = 8 bytes, 17.39%)

After the fix:

$ java -Xlog:aot -cp HelloWorld.jar -XX:ArchiveClassesAtExit=hw.jsa HelloWorld
...
[0.638s][info][aot] Allocated 46 objects of 2944 bytes in gaps (remain = 8 bytes, 0.27%)

(8 / (2944 + 8)) == 0.0027100271002710027

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Issue

• JDK-8385670: Incorrect warning: Unexpected gaps for Klass alignment (Bug - P4)

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