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Restore the vtable pointer of received cache nodes - #229
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Nodes in a cache reply are copied as raw bytes, vtable pointer included. Where processes map the executable at different addresses (a position-independent executable under address-space randomization, as on macOS) that pointer is invalid in the receiver and the first virtual call on a received node crashes: two-process runs failed on macOS this way. Fixed-address executables (readelf type EXEC, the usual Linux HPC build) are unaffected. The restore was already written and commented out; enable it. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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Sep 28, 2026
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Please correct the indicated comment to prevent confusion in the future. Thanks,
The saved pointer is now used by unpackSingle(). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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Sep 29, 2026
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Nodes in a node-cache reply are copied as raw bytes, vtable pointer included. Where processes map the executable at different addresses (a position-independent executable under address-space randomization, as on macOS, where every arm64 executable is PIE), that pointer is invalid in the receiving process and the first virtual call on a received node crashes. Two-process runs on macOS fail this way at the first remote fetch; single-process runs are unaffected. Fixed-address executables (readelf type EXEC, the usual Linux HPC build) never see it because every process loads the binary at its link address.
unpackSingle()already contained the restore, commented out with a note about an old PGI problem; this enables it.teststepenergy and restart pass at 1x2, 2x2, 3x2 and 2x1 processes on macOS and on Anvil with it.Orthogonal to the node-cache work in #228, which includes this commit; merging this first shrinks that diff.
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