#!/usr/bin/env bash
# run_vindex_concurrency_tests.sh — regression harness for the 2026-08-16 soul crash.
#
# Runs two halves. The PAIR is the point: the ASan control localises the defect to
# concurrency rather than to HNSW logic. See test_vindex_concurrency.c for the full
# story (SIGSEGV at ASCII address "gramNode", heap corruption in xzm_realloc, etc).
#
#   1. single     — ASan+UBSan, one thread. MUST be clean. Always a hard failure.
#   2. concurrent — TSan, writer + reader on one index. Currently EXPECTED to report a
#                   race at visited_reset, because VIndex still owns its visited[] +
#                   visit_epoch scratch. Once that moves to a per-query checkout pool
#                   this must go clean; flip EXPECT_RACE=0 then and it becomes a real
#                   regression gate.
#
# usage: run_vindex_concurrency_tests.sh
set -uo pipefail

HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
RUNTIME="$(cd "$HERE/../../lang/runtime" && pwd)"
WORK="$(mktemp -d)"
trap 'rm -rf "$WORK"' EXIT

SRC="$HERE/test_vindex_concurrency.c"
VINDEX="$RUNTIME/engram_vindex.c"

# Flip to 0 once the visited set is per-query; the concurrent half then becomes a gate.
EXPECT_RACE="${EXPECT_RACE:-1}"

fail=0

echo "== [1/2] single-threaded control under AddressSanitizer =="
cc -std=c11 -g -O1 -fsanitize=address,undefined -fno-omit-frame-pointer \
   -I"$RUNTIME" -o "$WORK/single" "$SRC" "$VINDEX" -lm || { echo "BUILD FAILED"; exit 2; }
if ASAN_OPTIONS=detect_leaks=0 "$WORK/single" single; then
  echo "   -> OK"
else
  echo "   -> FAIL: the single-threaded control must always be clean."
  echo "      If this fails the bug is NOT (only) concurrency — look for a real"
  echo "      out-of-bounds or lifetime error in engram_vindex.c."
  fail=1
fi

echo
echo "== [2/2] concurrent writer+reader under ThreadSanitizer =="
cc -std=c11 -g -O1 -fsanitize=thread -fno-omit-frame-pointer \
   -I"$RUNTIME" -o "$WORK/conc" "$SRC" "$VINDEX" -lm || { echo "BUILD FAILED"; exit 2; }

tsan_log="$WORK/tsan.log"
TSAN_OPTIONS="halt_on_error=0" "$WORK/conc" concurrent >"$tsan_log" 2>&1
if grep -q "ThreadSanitizer: data race" "$tsan_log"; then
  echo "   -> RACE DETECTED:"
  grep -m1 -A6 "ThreadSanitizer: data race" "$tsan_log" | sed 's/^/      /'
  if [ "$EXPECT_RACE" = "1" ]; then
    echo "   -> EXPECTED (VIndex still owns the shared visited set). Not a failure yet."
    echo "      Fix = per-query visited buffer (hnswlib VisitedListPool style), then"
    echo "      re-run with EXPECT_RACE=0."
  else
    echo "   -> REGRESSION: the visited set was supposed to be per-query."
    fail=1
  fi
else
  echo "   -> clean"
  if [ "$EXPECT_RACE" = "1" ]; then
    echo "   -> NOTE: no race reported, but EXPECT_RACE=1. Either the fix landed"
    echo "      (set EXPECT_RACE=0) or the test did not actually interleave."
  fi
fi

echo
[ "$fail" -eq 0 ] && echo "RESULT: PASS" || echo "RESULT: FAIL"
exit "$fail"