tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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maybe-garbage-collect.js (1759B)

      1 /**
      2 * maybeGarbageCollectAsync
      3 *
      4 * It might garbage collect, it might not. If it doesn't, that's ok.
      5 */
      6 self.maybeGarbageCollectAsync = garbageCollect;
      7 
      8 /**
      9 * maybeGarbageCollectKeptObjectsAsync
     10 *
     11 * Based on "asyncGCDeref" in https://github.com/tc39/test262/blob/master/harness/async-gc.js
     12 *
     13 * @return {Promise} Resolves to a trigger if ClearKeptObjects
     14 *                   exists to provide one
     15 */
     16 async function maybeGarbageCollectKeptObjectsAsync() {
     17  let trigger;
     18 
     19  if (typeof ClearKeptObjects === 'function') {
     20    trigger = ClearKeptObjects();
     21  }
     22 
     23  await maybeGarbageCollectAsync();
     24 
     25  return trigger;
     26 }
     27 
     28 /**
     29 * maybeGarbageCollectAndCleanupAsync
     30 *
     31 * Based on "asyncGC" in https://github.com/tc39/test262/blob/master/harness/async-gc.js
     32 *
     33 * @return {undefined}
     34 */
     35 async function maybeGarbageCollectAndCleanupAsync(...targets) {
     36  let finalizationRegistry = new FinalizationRegistry(() => {});
     37  let length = targets.length;
     38 
     39  for (let target of targets) {
     40    finalizationRegistry.register(target, 'target');
     41    target = null;
     42  }
     43 
     44  targets = null;
     45 
     46  await 'tick';
     47  await maybeGarbageCollectKeptObjectsAsync();
     48 
     49  let names = [];
     50 
     51  finalizationRegistry.cleanupSome(name => names.push(name));
     52 
     53  if (names.length !== length) {
     54    throw maybeGarbageCollectAndCleanupAsync.NOT_COLLECTED;
     55  }
     56 }
     57 
     58 maybeGarbageCollectAndCleanupAsync.NOT_COLLECTED = Symbol('Object was not collected');
     59 
     60 /**
     61 * resolveGarbageCollection
     62 *
     63 * Based on "resolveAsyncGC" in https://github.com/tc39/test262/blob/master/harness/async-gc.js
     64 *
     65 * @param  {Error} error An error object.
     66 * @return {undefined}
     67 */
     68 function resolveGarbageCollection(error) {
     69  if (error && error !== maybeGarbageCollectAndCleanupAsync.NOT_COLLECTED) {
     70    throw error;
     71  }
     72 }