Simpler using compressed oops flag representation #15509
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This commit modifies the internal representation of the JVM flag UseCompressedOops to just be a String. This means we can just store the value of the flag or "unknown" directly so that we do not have to engage in shenanigans with three-valued logic around a boxed boolean. Relates #15489
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The ultimate endgame here is simpler handling in the backwards compatibility code in the 2.x line so that we can distinguish between "true", "false" and "unknown" from a >= 2.2.0 node, and null from a < 2.2.0 node. |
| } else { | ||
| usingCompressedOops = null; | ||
| } | ||
| useCompressedOops = in.readOptionalString(); |
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@nik9000 Not in master, good catch. I'll remove the optional for master but it will be needed on the 2.x backport.
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LGTM - I left a comment asking about the return value from the jvm's info API. Maybe if it returns null we should set it to "unknown". |
| @@ -307,7 +314,7 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws | |||
| builder.field(Fields.GC_COLLECTORS, gcCollectors); | |||
| builder.field(Fields.MEMORY_POOLS, memoryPools); | |||
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| builder.field(Fields.USING_COMPRESSED_OOPS, usingCompressedOops == null ? "unknown" : Boolean.toString(usingCompressedOops)); | |||
| builder.field(Fields.USING_COMPRESSED_OOPS, useCompressedOops); | |||
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If it can be null we should skip it here.
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@nik9000 Yes, that's exactly how it will be on the backport but it's not needed here.
The return from the API can not be null. |
…resentation Simpler using compressed oops flag representation
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Thank you for reviewing @nik9000. |
This commit modifies the internal representation of the JVM flag
UseCompressedOops to just be a String. This means we can just store the
value of the flag or "unknown" directly so that we do not have to engage
in shenanigans with three-valued logic around a boxed boolean.
Relates #15489