tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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tenuring.js (2338B)

      1 // Check that we switch to allocating in the tenured heap after the first
      2 // nursery collection.
      3 
      4 function buildObjectTree(depth) {
      5  if (depth === 0) {
      6    return "leaf";
      7  }
      8 
      9  return {
     10    left: buildObjectTree(depth - 1),
     11    right: buildObjectTree(depth - 1)
     12  };
     13 }
     14 
     15 function buildArrayTree(depth) {
     16  if (depth === 0) {
     17    return [];
     18  }
     19 
     20  return [
     21    buildArrayTree(depth - 1),
     22    buildArrayTree(depth - 1)
     23  ];
     24 }
     25 
     26 function testRoundTrip(depth, objectTree, expectedNurseryAllocated) {
     27  const input = objectTree ? buildObjectTree(depth) : buildArrayTree(depth);
     28 
     29  gc();
     30  const initialMinorNumber = gcparam('minorGCNumber');
     31 
     32  const output = deserialize(serialize(input));
     33  checkHeap(output, depth, objectTree, expectedNurseryAllocated);
     34 
     35  const minorCollections = gcparam('minorGCNumber') - initialMinorNumber;
     36  const expectedMinorCollections = expectedNurseryAllocated ? 0 : 1;
     37  assertEq(minorCollections, expectedMinorCollections);
     38 }
     39 
     40 function checkHeap(tree, depth, objectTree, expectedNurseryAllocated) {
     41  const counts = countHeapLocations(tree, objectTree);
     42 
     43  const total = counts.nursery + counts.tenured;
     44  assertEq(total, (2 ** (depth + 1)) - 1);
     45 
     46  if (expectedNurseryAllocated) {
     47    assertEq(counts.tenured, 0);
     48    assertEq(counts.nursery >= 1, true);
     49  } else {
     50    assertEq(counts.tenured >= 1, true);
     51    // We get a single nursery allocation when we trigger minor GC.
     52    assertEq(counts.nursery <= 1, true);
     53  }
     54 }
     55 
     56 function countHeapLocations(tree, objectTree, counts) {
     57  if (!counts) {
     58    counts = {nursery: 0, tenured: 0};
     59  }
     60 
     61  if (isNurseryAllocated(tree)) {
     62    counts.nursery++;
     63  } else {
     64    counts.tenured++;
     65  }
     66 
     67  if (objectTree) {
     68    if (tree !== "leaf") {
     69      countHeapLocations(tree.left, objectTree, counts);
     70      countHeapLocations(tree.right, objectTree, counts);
     71    }
     72  } else {
     73    if (tree.length !== 0) {
     74      countHeapLocations(tree[0], objectTree, counts);
     75      countHeapLocations(tree[1], objectTree, counts);
     76    }
     77  }
     78 
     79  return counts;
     80 }
     81 
     82 gczeal(0);
     83 gcparam('minNurseryBytes', 1024 * 1024);
     84 gcparam('maxNurseryBytes', 1024 * 1024);
     85 gcparam('semispaceNurseryEnabled', 0);
     86 gc();
     87 
     88 testRoundTrip(1, true, true);
     89 testRoundTrip(1, false, true);
     90 testRoundTrip(4, true, true);
     91 testRoundTrip(4, false, true);
     92 testRoundTrip(15, true, false);
     93 testRoundTrip(15, false, false);