Hacktoberfest 2026: los issues que los mantenedores marcaron para octubre, abiertos y aptos para principiantes. Explorar issues de Hacktoberfest

String-scaling gate misses quadratic len-of scans because length is measured outside the timer

Abierto
  • ¿Algo no está bien?
#1,192 1 comentario 0 reacciones 0 asignados Ver en GitHub

Los mantenedores suelen responder en 1 día

Nadie ha tomado este issue todavía.

Evaluación

Dificultad
3/5
Tiempo estimado
1-2 días
Aptitud para principiantes
68/100
Tipo de issue
Error
Claridad
Bastante claro
Estado de actividad
Activo
Stack tecnológico
c, shell
Área
performance, testing-qa

Línea de trabajo

Start with tests/test_string_scaling.sh and inspect the builtin_len change described in the issue. Reproduce the current and mutant timings with the supplied commands, then add separately timed len-of-in-loop coverage with a cache-removal control, or narrow the gate's stated coverage. Preserve the existing indexing coverage and verify the gate distinguishes both regressions.

Escrito por el modelo de indexación a partir del texto del issue.

Descripción

area:gates found-by:critic kind:gate-defect

The string-scaling gate enrolled by PR #1187 claims len of coverage in its header, but its only len of s call is before t0. The timed scan uses the saved n, so removal of the length cache in builtin_len is invisible to it.

Independently reproduced at 0c680102cfe6ac7f961c8a0eb76267a00fed0605. The only runtime mutation was:

 Value* builtin_len(Value *arg) {
@@
     if (arg->type == VAL_STR)
-        return make_num(val_str_len(arg));
+        return make_num(strlen(arg->data.strv.ptr));

I compiled that translation unit with the release recipe and linked it with the current release objects. No fake runtime, timing stub, environment replay, or altered gate was involved. The modified runtime returns the same lengths.

The untouched gate passed three times at 2.01, 2.01, 2.02 (rc 0). It would pass the former 2.60 threshold as well as 2.90. Meanwhile the real pre-#1185 indexing binary failed three times at 4.34, 4.52, 4.48; the instrument still detects that original regression.

To expose the missed class, I extracted the gate's actual scan program and changed only its loop condition from i < n to i < (len of s). Five interleaved release/mutant samples per length, JIT off, all child exits 0 and all scan counts correct:

Runtime 20k median ms 40k 80k Doubling ratios
Current release 12.023219 23.421235 48.285582 1.948, 2.062
builtin_len cache removed 38.151753 140.258292 471.863735 3.676, 3.364

This is a workload-coverage class, not a claim that changing the threshold caused this hole: a named operation used only in setup cannot contribute its complexity to the verdict. Add a separately timed len of-in-loop workload (with a real cache-removal fault control), or narrow the stated coverage explicitly. Retain separate indexing coverage rather than blending timings so one operation can dilute another.

Local reproduction artifacts: /tmp/strenrol-r4/real-regression.py, len-regression/commands.json, len-regression/mutation.diff, real-gate-results.json, scan-len.eigs, and len-loop-samples.json.

cd /home/jon/src/InauguralSystems/EigenScriptEcosystem/EigenScript
EIGS=/tmp/strenrol-r4/len-regression/eigenscript bash tests/test_string_scaling.sh
EIGS_JIT_OFF=1 /tmp/strenrol-r4/len-regression/eigenscript /tmp/strenrol-r4/scan-len.eigs 80000
Lenguaje dominante
C
Estrellas
3
Forks
7
Merge medio
3 h 58 min
PR fusionados (30 d)
105

Preparar el entorno

Abrir en Codespaces

Inicia el contenedor de desarrollo del proyecto en tu navegador, con tu propia cuenta de GitHub.

Primeros pasos

  1. Lee el issue completo y luego la guía de contribución del proyecto.
  2. Comenta en el issue que vas a ocuparte — evita que dos personas hagan lo mismo.
  3. Haz un fork del repositorio y trabaja en una rama.
  4. Abre un pull request que haga referencia al número del issue.

Más de InauguralSystems/EigenScript

Todos los issues de InauguralSystems/EigenScript

Issues similares

Más issues de C

Recibe los nuevos issues en tu correo

Un resumen breve de issues de GitHub para principiantes.