bug-2045416.js - mozsearch

Enable keyboard shortcuts

gczeal(0);

const gC = newGlobal({newCompartment: true}); // zone C: transplantable targets (not collected)

const gZ = newGlobal({newCompartment: true}); // zone Z: dead weakrefs (collected)

const gD = newGlobal({newCompartment: true}); // zone D: transplant destination (not collected)

const NT = 64;       // number of important weakref/target pairs

const NFILLER = 200000; // dead weakrefs in Z to stall foreground finalization

gC.evaluate(`

  var pairs = [];

  for (let i = 0; i < ${NT}; i++) pairs.push(transplantableObject());

`);

gZ.evaluate(`

  function makeWeak(t) { new WeakRef(t); }

  function filler(n) {

    let keep = [];

    for (let i = 0; i < n; i++) { let o = {i: i}; keep.push(o); new WeakRef(o); }

    return keep;

`);

// Fillers first: their (dead) weakrefs are finalized first and stall

// foreground finalization across many slices. Targets stay alive via `keep`.

let keep = gZ.filler(NFILLER);

// Important weakrefs last: their arenas are finalized last.

for (let i = 0; i < NT; i++) {

  gZ.makeWeak(gC.pairs[i].object);

// Clean nursery + store buffer before starting; tenure everything live.

minorgc();

// Incremental GC collecting ONLY zone Z.

schedulezone(gZ);

startgc(1);

let transplanted = 0;

let sliceCount = 0;

while (gcstate() !== "NotActive") {

  gcslice(10000, {dontStart: true});

  sliceCount++;

  if (gcstate() === "Sweep" && transplanted < NT) {

    for (let k = 0; k < 4 && transplanted < NT; k++) {

      // Transplant target into zone D. The new identity proxy is

      // nursery-allocated; relocateFinalizationObserverTarget writes it into

      // the dead WeakRef's TargetSlot -> whole-cell entry for dead cell.

      gC.pairs[transplanted].transplant(gD);

      transplanted++;

  if (sliceCount > 10000) { break; }

minorgc();