#!/usr/bin/env bash
set -euo pipefail

# Measure steady-state RSS for Tiny sizes by maintaining a live set
# and churning short-lived allocations. Reports peak and end RSS.
#
# Usage: scripts/measure_rss_tiny.sh <size> <live_count> <iters>

ROOT_DIR=$(cd "$(dirname "$0")/.." && pwd)
cd "$ROOT_DIR"

if [[ $# -lt 3 ]]; then
  echo "usage: $0 <size> <live_count> <iters>" >&2
  exit 1
fi
size=$1; live=$2; iters=$3

cat > "$ROOT_DIR/.tmp_rss_bench.c" <<'EOF'
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

static size_t get_rss_kb(void) {
  FILE* f = fopen("/proc/self/statm","r");
  if (!f) return 0; unsigned long size, res; fscanf(f, "%lu %lu", &size, &res); fclose(f);
  long ps = sysconf(_SC_PAGESIZE); return (size_t)((res * ps) / 1024);
}

int main(int argc, char** argv) {
  size_t size = (size_t)strtoull(argv[1],NULL,10);
  int live = atoi(argv[2]);
  int iters = atoi(argv[3]);
  void** L = (void**)malloc(sizeof(void*)*(size_t)live);
  for (int i=0;i<live;i++) L[i] = malloc(size);
  size_t peak=0;
  for (int it=0; it<iters; it++) {
    for (int i=0;i<live;i+=2) { free(L[i]); L[i]=malloc(size); }
    size_t rss = get_rss_kb(); if (rss>peak) peak=rss;
  }
  size_t end_rss = get_rss_kb();
  printf("peak_rss_kb=%zu end_rss_kb=%zu\n", peak, end_rss);
  for (int i=0;i<live;i++) free(L[i]); free(L); return 0;
}
EOF

gcc -O3 -march=native -mtune=native .tmp_rss_bench.c -o .tmp_rss_bench

echo "[info] Building shared lib (for LD_PRELOAD HAKMEM case)"
make -s pgo-build-shared >/dev/null || true

echo "[case] HAKMEM (LD_PRELOAD)"
out_h=$(HAKMEM_LD_SAFE=1 LD_PRELOAD="$ROOT_DIR/libhakmem.so" ./.tmp_rss_bench "$size" "$live" "$iters")
echo "$out_h"

echo "[case] System"
out_s=$(./.tmp_rss_bench "$size" "$live" "$iters")
echo "$out_s"

rm -f .tmp_rss_bench .tmp_rss_bench.c