feat(threads): resolve non-JIT PR-249 tail (#428)

Author: chrisbbreuer

.github/workflows/ci.yml

@@ -71,12 +71,10 @@ jobs:
             cmd: zig build threads-test -Dthreads-shard-index=3 -Dthreads-shard-count=4
           - name: threads-nogil-witness
             cmd: zig build threads-test -Dthreads-parallel-js=true -Dthreads-case=sync/condition-wait-notify.js
-          # Reference-only corpus hygiene: fail if a non-promoted PR-249 file
-          # loses its blocker classification or if one of the nearest
-          # promotion probes starts passing or changes failure shape without the
-          # allowlist/docs being updated in the same change.
+          # PR-249 corpus hygiene: reject inventory/disposition drift and verify
+          # the bounded terminal-premise probes against the installed runner.
           - name: threads-reference-audit
-            cmd: zig build threads-reference-audit && python3 tools/threads-reference-audit.py --run-probes --expect-current-blockers --probe-timeout 60
+            cmd: zig build threads-reference-audit threads-reference-probes
           - name: benchmark-comparison-harness
             cmd: zig build benchmark-comparison-test
           - name: wasm-feature-profiles

build.zig

@@ -1384,20 +1384,21 @@ pub fn build(b: *std.Build) void {
         "--check-inventory",
         "--self-test-inventory",
     });
-    const threads_reference_audit_step = b.step("threads-reference-audit", "Audit remaining reference-only PR-249 files");
+    const threads_reference_audit_step = b.step("threads-reference-audit", "Audit promoted, blocked, and terminal PR-249 files");
     threads_reference_audit_step.dependOn(&threads_reference_audit_cmd.step);
 
     const threads_reference_probes_cmd = b.addSystemCommand(&.{
         "python3",
         "tools/threads-reference-audit.py",
         "--fail-on-uncategorized",
-        "--run-probes",
-        "--expect-current-blockers",
+        "--run-disposition-probes",
+        "--expect-terminal-dispositions",
         "--skip-timeout-probes",
         "--probe-timeout",
         "20",
     });
-    const threads_reference_probes_step = b.step("threads-reference-probes", "Verify quick PR-249 reference-only promotion blockers");
+    threads_reference_probes_cmd.step.dependOn(&threads_test_install.step);
+    const threads_reference_probes_step = b.step("threads-reference-probes", "Verify quick PR-249 terminal dispositions");
     threads_reference_probes_step.dependOn(&threads_reference_probes_cmd.step);
 
     // Concurrent-JS fuzzer: `zig build threadfuzz [-Dtsan] [-Dfuzz-iters=N] [-Dfuzz-seed=S]`.

conformance/threads_test.zig

@@ -27,6 +27,7 @@ const allowlist = [_][]const u8{
     "dw1-sort-comparator-callsite-shapes.js",
     "dw1-sort-comparator-iterator-host.js",
     "dw1-sort-comparator-osr.js",
+    "dw2-marklistset-storm.js",
     "api/condition-basic.js",
     "api/condition-async-wait.js",
     "api/condition-wait-termination.js",
@@ -65,6 +66,11 @@ const allowlist = [_][]const u8{
     "bench/megamorphic-access.js",
     "bench/transition-heavy-constructor.js",
     "congc-t1-window-split.js",
+    "congc-t3-barrier-storm.js",
+    "congc-t4-alloc-steal-storm.js",
+    "congc-t5-celllock-audit.js",
+    "congc-t9-attach-exit-churn.js",
+    "congc-t11-diagnostics.js",
     "cve/mc-aint-terminate-notify-park-race.js",
     "cve/mc-code-deferred-fire-stale-window.js",
     "cve/mc-code-sleep-through-jettison-isb.js",
@@ -77,6 +83,8 @@ const allowlist = [_][]const u8{
     "cve/mc-gc-blocked-native-roots.js",
     "cve/mc-gc-finreg-cross-thread-gc.js",
     "cve/mc-gc-thread-shell-finalizer-storm.js",
+    "cve/mc-gc-weakgcmap-registry-vs-prune.js",
+    "cve/mc-grow-buffer-storm.js",
     "cve/mc-grow-s4-detach-nullvec-repro.js",
     "cve/mc-grow-wasm-relocating-grow.js",
     "cve/mc-hand-dead-registrant-settle.js",
@@ -284,6 +292,29 @@ fn usesBenchHarness(name: []const u8) bool {
         std.mem.eql(u8, name, "jit/fires-per-sec.js");
 }
 
+fn appendCaseSource(gpa: std.mem.Allocator, buf: *std.ArrayListUnmanaged(u8), name: []const u8, source: []const u8) !void {
+    if (builtin.sanitize_thread and std.mem.eql(u8, name, "dw2-marklistset-storm.js")) {
+        // Preserve two worker sort/apply lanes plus the main mutator and an
+        // explicit GC requester,
+        // and the explicit r=16 GC request while bounding TSan's >100x cost.
+        // Normal builds execute the untouched 16 x 120 shape; the sanitizer
+        // gate executes 2 x 18 plus main/reference passes. Fail closed if the
+        // pinned fixture changes instead of silently running another shape.
+        const workers_needle = "const W = HAVE_THREADS ? 16 : 1;";
+        const rounds_needle = "const ROUNDS = 120;";
+        const workers_at = std.mem.indexOf(u8, source, workers_needle) orelse return error.CorpusFixtureDrift;
+        const rounds_at = std.mem.indexOf(u8, source, rounds_needle) orelse return error.CorpusFixtureDrift;
+        if (rounds_at <= workers_at) return error.CorpusFixtureDrift;
+        try buf.appendSlice(gpa, source[0..workers_at]);
+        try buf.appendSlice(gpa, "const W = HAVE_THREADS ? 2 : 1;");
+        try buf.appendSlice(gpa, source[workers_at + workers_needle.len .. rounds_at]);
+        try buf.appendSlice(gpa, "const ROUNDS = 18;");
+        try buf.appendSlice(gpa, source[rounds_at + rounds_needle.len ..]);
+        return;
+    }
+    try buf.appendSlice(gpa, source);
+}
+
 fn parallelJsBudgetSkip(name: []const u8) bool {
     _ = name;
     return false;
@@ -717,7 +748,7 @@ pub fn main(init: std.process.Init) !void {
                 try buf.appendSlice(gpa, vmstate_workload_src);
                 try buf.appendSlice(gpa, "\n");
             }
-            try buf.appendSlice(gpa, test_src);
+            try appendCaseSource(gpa, &buf, name, test_src);
 
             // Per-file configs, mirroring their run-tests.sh / //@ runDefault
             // lines: blocking-gate runs can-block-is-false; thread-id-bounds runs

docs/.data/pr249-non-jit-resolution-2026-07-21.json

@@ -0,0 +1,125 @@
+{
+  "schema_version": 1,
+  "issue": 428,
+  "date": "2026-07-21",
+  "source_head": "3a14f2a821ac56fcb01d1c765200be7e9dfdb458",
+  "runner": {
+    "build": "zig build threads-test-bin -Doptimize=ReleaseFast",
+    "default": "zig-out/bin/threads-test one <case>",
+    "parallel_js": "zig-out/bin/threads-test parallel-js one <case>",
+    "tsan_parallel_js": "zig build threads-test-bin -Dtsan=true -Doptimize=ReleaseSafe; zig-out/bin/threads-test parallel-js one <promoted-case>",
+    "tsan_ci_debug": "zig build threads-test-bin -Dtsan=true; zig-out/bin/threads-test parallel-js one dw2-marklistset-storm.js",
+    "tsan_dw2_profile": "2 workers x 18 rounds plus main; worker seed 0 requests GC at r=16 while worker seed 1 and main mutate (normal build remains 16 x 120)"
+  },
+  "summary": {
+    "cases": 14,
+    "mode_runs": 28,
+    "promoted": 8,
+    "terminal_dispositions": 6,
+    "tsan_mode_runs": 8,
+    "tsan_pass": 8,
+    "tsan_ci_debug_runs": 1,
+    "tsan_ci_debug_pass": 1
+  },
+  "cases": [
+    {
+      "case": "api/wasm-refused-sd7.js",
+      "resolution": "terminal-disposition",
+      "default": { "status": "fail", "elapsed_ms": 2 },
+      "parallel_js": { "status": "fail", "elapsed_ms": 2 },
+      "evidence": "expected TypeError but got no-throw"
+    },
+    {
+      "case": "congc-t2-lockorder-lint.js",
+      "resolution": "terminal-disposition",
+      "default": { "status": "pass", "elapsed_ms": 1 },
+      "parallel_js": { "status": "pass", "elapsed_ms": 2 },
+      "evidence": "only the trailing arithmetic sanity branch executes"
+    },
+    {
+      "case": "congc-t3-barrier-storm.js",
+      "resolution": "promoted",
+      "default": { "status": "pass", "elapsed_ms": 1112 },
+      "parallel_js": { "status": "pass", "elapsed_ms": 1785 },
+      "tsan_parallel_js": { "status": "pass", "elapsed_ms": 244001 }
+    },
+    {
+      "case": "congc-t4-alloc-steal-storm.js",
+      "resolution": "promoted",
+      "default": { "status": "pass", "elapsed_ms": 717 },
+      "parallel_js": { "status": "pass", "elapsed_ms": 1309 },
+      "tsan_parallel_js": { "status": "pass", "elapsed_ms": 150481 }
+    },
+    {
+      "case": "congc-t5-celllock-audit.js",
+      "resolution": "promoted",
+      "default": { "status": "pass", "elapsed_ms": 500 },
+      "parallel_js": { "status": "pass", "elapsed_ms": 720 },
+      "tsan_parallel_js": { "status": "pass", "elapsed_ms": 42376 }
+    },
+    {
+      "case": "congc-t8-stop-interleaving.js",
+      "resolution": "terminal-disposition",
+      "default": { "status": "pass", "elapsed_ms": 3 },
+      "parallel_js": { "status": "pass", "elapsed_ms": 2 },
+      "evidence": "the sharedHeapTest-gated body is not entered"
+    },
+    {
+      "case": "congc-t9-attach-exit-churn.js",
+      "resolution": "promoted",
+      "default": { "status": "pass", "elapsed_ms": 190 },
+      "parallel_js": { "status": "pass", "elapsed_ms": 329 },
+      "tsan_parallel_js": { "status": "pass", "elapsed_ms": 21689 }
+    },
+    {
+      "case": "congc-t11-diagnostics.js",
+      "resolution": "promoted",
+      "default": { "status": "pass", "elapsed_ms": 131 },
+      "parallel_js": { "status": "pass", "elapsed_ms": 395 },
+      "tsan_parallel_js": { "status": "pass", "elapsed_ms": 27777 }
+    },
+    {
+      "case": "cve/mc-df-arraycopy-relabel.js",
+      "resolution": "terminal-disposition",
+      "default": { "status": "fail", "elapsed_ms": 2 },
+      "parallel_js": { "status": "fail", "elapsed_ms": 2 },
+      "evidence": "RangeError: offset is out of bounds"
+    },
+    {
+      "case": "cve/mc-gc-weakgcmap-registry-vs-prune.js",
+      "resolution": "promoted",
+      "default": { "status": "pass", "elapsed_ms": 247 },
+      "parallel_js": { "status": "pass", "elapsed_ms": 321 },
+      "tsan_parallel_js": { "status": "pass", "elapsed_ms": 10293 }
+    },
+    {
+      "case": "cve/mc-grow-buffer-storm.js",
+      "resolution": "promoted",
+      "default": { "status": "pass", "elapsed_ms": 1215 },
+      "parallel_js": { "status": "pass", "elapsed_ms": 1434 },
+      "tsan_parallel_js": { "status": "pass", "elapsed_ms": 61561 }
+    },
+    {
+      "case": "cve/mc-life-creator-thread-dies.js",
+      "resolution": "terminal-disposition",
+      "default": { "status": "fail", "elapsed_ms": 4 },
+      "parallel_js": { "status": "fail", "elapsed_ms": 5 },
+      "evidence": "TypeError: Cannot construct a TypedArray on a detached buffer"
+    },
+    {
+      "case": "dw2-marklistset-storm.js",
+      "resolution": "promoted",
+      "default": { "status": "pass", "elapsed_ms": 4512 },
+      "parallel_js": { "status": "pass", "elapsed_ms": 5909 },
+      "tsan_parallel_js": { "status": "pass", "elapsed_ms": 26726 },
+      "tsan_ci_debug": { "status": "pass", "elapsed_ms": 326285 }
+    },
+    {
+      "case": "w16-c1-prevent-collection.js",
+      "resolution": "terminal-disposition",
+      "default": { "status": "pass", "elapsed_ms": 3823 },
+      "parallel_js": { "status": "pass", "elapsed_ms": 7890 },
+      "evidence": "snapshot/preventCollection branches are unavailable"
+    }
+  ]
+}