weakmap-expose.js - mozsearch

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// Test that WeakMap.get() doesn't return a gray GC thing.

function checkNotGray(value) {

  // Assigning a gray GC thing to an object propery will assert.

  let test = {};

  test.property = value;

// 1. Make a black WeakMap with a gray key and gray value.

gczeal(0);

let key = {};

let value = {};

let map = new WeakMap();

map.set(key, value);

let gray = grayRoot();

gray.key = key;

addMarkObservers([map, key, value]);

gray = null;

key = null;

value = null;

gc();

let marks = getMarks();

assertEq(marks[0], "black");

assertEq(marks[1], "gray");

assertEq(marks[2], "gray");

// 2. Get our key back, which will expose it and mark it black.

key = nondeterministicGetWeakMapKeys(map)[0];

checkNotGray(key);

// 3. Look up the value in the map and check it's not gray.

value = map.get(key);

checkNotGray(value);