Files
peltier.io/results/cjson/coz/README.md
T
Claude 832dab3445 phase3: coz integration status; cjson C pipeline proven end-to-end
- coz wired (harness -DHOTPATH_COZ hook, scripts, just coz) + installed,
  but the apt coz runtime aborts in its own init_coz/pthread_create
  interposition on this glibc (known coz bug, reproduces on the pristine
  binary). Documented in results/cjson/coz/README.md; callgrind cache-sim
  is the working profiler.
- cjson no-op verdict smoke: full C pipeline flows (clang {out} baseline
  rebuild, Unity/CTest + golden gates, interleaved bench) to a correct
  null result (median 0.9995).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EcKPWQ3MQD4NdEHwar96u2
2026-07-11 18:38:04 +00:00

1.1 KiB

coz on cjson — integration status

coz is wired into the harness (SPEC §12): targets/cjson/harness.c carries a -DHOTPATH_COZ throughput progress point, and scripts/coz-profile.sh + just coz cjson build the instrumented binary and run coz run. scripts/coz-summary.py ranks lines by causal throughput effect.

Runtime limitation in this container: the distro coz-profiler (apt) aborts inside its own init_coz during startup — pthread_create interposition recurses ("init_coz in progress, do not recurse" → SIGABRT) before main runs. This is a known coz/glibc incompatibility on newer glibc, independent of the harness. It reproduces on the pristine binary with a bare coz run, so it is not our instrumentation.

What we use instead: callgrind --cache-sim --branch-sim (results/cjson/hotspots.txt) is the working profiler and gives an unambiguous class-selection signal for cjson — glibc float serialization/parsing (__printf_fp, strtod) plus cJSON parse_value/print_value dominate. The coz path is ready for an environment with a compatible coz runtime (bench-metal / a pinned coz build); no code change is needed there.