hakorune/examples/gc_counting_demo.hako

// GC Counting demo (VM path) — verifies CountingGc counters and barrier sites
// Run:
//   ./target/release/hakorune --backend vm examples/gc_counting_demo.hako
// Expect (with trace): [GC] counters: safepoints>0 read_barriers>=0 write_barriers>=0

static box Main {
  main() {
    // Turn on Counting GC + trace via Box-First path
    local G
    G = new GcConfigBox()
    G = G.setFlag("counting", true)
    G = G.setFlag("trace", true)
    G.apply()

    // Make sure we don't engage JIT path for this demo (VM baseline)
    // If needed, you can set NYASH_JIT_EXEC=0 in the environment.

    // Perform some mutating ops to hit write barriers on the VM path
    local A, M
    A = new ArrayBox()
    A.push(1)
    A.set(0, 2)

    M = new MapBox()
    M.set("k", "v")

    // Simple read ops (should register read barriers on some implementations)
    print(A.length())
    print(M.size())

    return "done"
  }
}