ccws-as-weakmap-keys.js

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// Test weak maps with keys in different zones, checking whether entries are

// collected when we expect. The existance of CCWs from uncollected zones

// keeps keys alive and prevents entries from being collected.

gczeal(0);

function mapSize(wm) {

  // Note: Using nondeterministicGetWeakMapKeys will create CCWs to the keys

  // if they are in a different compartment.

  return nondeterministicGetWeakMapSize(wm);

let keyZone = newGlobal({newCompartment: true});

let mapZone = newGlobal({newCompartment: true});

printErr("Test 1: Full GC");

keyZone.eval('var key = makeFinalizeObserver();');

mapZone.eval('var map = new WeakMap;');

mapZone.map.set(keyZone.key, {});

let initialCount = finalizeCount();

assertEq(mapSize(mapZone.map), 1);

gc();

assertEq(finalizeCount(), initialCount);

assertEq(mapSize(mapZone.map), 1);

keyZone.key = undefined;

gc();

assertEq(finalizeCount(), initialCount + 1);

assertEq(mapSize(mapZone.map), 0);

mapZone.map = undefined;

gc();

printErr("Test 2: Zone GC");

keyZone.eval('var key = makeFinalizeObserver();');

mapZone.eval('var map = new WeakMap;');

mapZone.keyZone = keyZone;

mapZone.eval('map.set(keyZone.key, {});');

mapZone.keyZone = undefined;

assertEq(mapSize(mapZone.map), 1);

initialCount = finalizeCount();

printErr("  2.1 Setup");

gc();

keyZone.key = undefined;

assertEq(finalizeCount(), initialCount);

assertEq(mapSize(mapZone.map), 1);

printErr("  2.2 Collect only main zone (key not collected)");

gc(this);

assertEq(finalizeCount(), initialCount);

assertEq(mapSize(mapZone.map), 1);

printErr("  2.3 Collect only map zone (key not collected)");

gc(mapZone);

assertEq(finalizeCount(), initialCount);

assertEq(mapSize(mapZone.map), 1);

printErr("  2.4 Collect only key zone (key not collected)");

gc(keyZone);

assertEq(finalizeCount(), initialCount);

assertEq(mapSize(mapZone.map), 1);

printErr("  2.5 Collect key zone and map zone (key collected)");

schedulezone(keyZone);

schedulezone(mapZone);

gc('zone');

assertEq(finalizeCount(), initialCount + 1);

assertEq(mapSize(mapZone.map), 0);