1 files changed, 70 insertions, 0 deletions
diff --git a/external/dualprop_patches/0016-experiment-lock-P2-source-and-cell-registry.patch b/external/dualprop_patches/0016-experiment-lock-P2-source-and-cell-registry.patch
new file mode 100644
index 0000000..47fd5b6
--- /dev/null
+++ b/external/dualprop_patches/0016-experiment-lock-P2-source-and-cell-registry.patch
@@ -0,0 +1,70 @@
+From 18b17f442b045686bee420b81b3e889cb80fd71e Mon Sep 17 00:00:00 2001
+From: YurenHao0426 <Blackhao0426@gmail.com>
+Date: Mon, 27 Jul 2026 13:51:07 -0500
+Subject: [PATCH 16/19] experiment: lock P2 source and cell registry
+
+---
+ crossover_grid.py | 40 ++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 40 insertions(+)
+
+diff --git a/crossover_grid.py b/crossover_grid.py
+index cbd9b98..4523250 100644
+--- a/crossover_grid.py
++++ b/crossover_grid.py
+@@ -180,6 +180,43 @@ def p2_jobs():
+     ]
+ 
+ 
++def p2_registry_sha256(jobs):
++    encoded = json.dumps(
++        jobs, sort_keys=True, separators=(",", ":")).encode("utf-8")
++    return hashlib.sha256(encoded).hexdigest()
++
++
++def ensure_p2_launch(source, jobs):
++    path = os.path.join(ROOT, "runs", "plain-p2-launch.json")
++    immutable = {
++        "stage": "p2",
++        "source": source,
++        "selector_path": SELECTOR,
++        "selector_sha256": SELECTOR_SHA256,
++        "num_registered_cells": len(jobs),
++        "registry_sha256": p2_registry_sha256(jobs),
++        "jobs": jobs,
++    }
++    if os.path.exists(path):
++        with open(path, encoding="utf-8") as handle:
++            existing = json.load(handle)
++        for key, value in immutable.items():
++            if existing.get(key) != value:
++                raise RuntimeError(f"P2 launch lock drift in {key}")
++        return path
++    record = {**immutable, "created_unix_time": time.time()}
++    os.makedirs(os.path.dirname(path), exist_ok=True)
++    try:
++        descriptor = os.open(
++            path, os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0o644)
++    except FileExistsError:
++        return ensure_p2_launch(source, jobs)
++    with os.fdopen(descriptor, "w", encoding="utf-8") as handle:
++        json.dump(record, handle, indent=2, sort_keys=True)
++        handle.write("\n")
++    return path
++
++
+ def p2_command(method, architecture, rate):
+     cli_method = {
+         "bp": "backprop",
+@@ -673,6 +710,9 @@ def main():
+         raise ValueError("invalid shard")
+     source = source_report()
+     jobs = p1_jobs() if args.stage == "p1" else p2_jobs()
++    if args.stage == "p2" and not args.dry_run:
++        launch = ensure_p2_launch(source, jobs)
++        print(f"P2 launch lock: {launch}", flush=True)
+     if args.method:
+         jobs = [job for job in jobs if job["method"] == args.method]
+     jobs = [
+-- 
+2.54.0
+