Permute indy invoke paths to reduce uncached stack#8410
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headius wants to merge 1 commit intojruby:9.5-devfrom
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Permute indy invoke paths to reduce uncached stack#8410headius wants to merge 1 commit intojruby:9.5-devfrom
headius wants to merge 1 commit intojruby:9.5-devfrom
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Passing all uncached calls through the varargs form simplifies maintenance, but requires an indirect dispatch for the first invocation. This adds several frames to the stack for such uncached calls. The patch here permutes the InvokeSite.invoke methods so they can directly dispatch to the to-be-cached handle, reducing the number of stack frames in a backtrace. This is unlikely to reduce actual stack consumption due to the unoptimized MethodHandle and LambdaForm between the invokeExact call and the target method.
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Thread dump showing actual stack used for the more direct form (AFTER): As described above, the MethodHandle guts are actually on the stack consuming stack space, so the change in this PR is mostly cosmetic affecting only user-facing stack traces. |
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Still some missing adaptation for SelfInvokeSite and others may be affected: |
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Passing all uncached calls through the varargs form simplifies maintenance, but requires an indirect dispatch for the first invocation. This adds several frames to the stack for such uncached calls. The patch here permutes the InvokeSite.invoke methods so they can directly dispatch to the to-be-cached handle, reducing the number of stack frames in a backtrace.
This is unlikely to reduce actual stack consumption due to the unoptimized MethodHandle and LambdaForm between the invokeExact call and the target method.
Example trace before and after:
BEFORE:
AFTER: