tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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browser_memory_allocations_01.js (3532B)

      1 /* Any copyright is dedicated to the Public Domain.
      2 * http://creativecommons.org/publicdomain/zero/1.0/ */
      3 
      4 "use strict";
      5 
      6 add_task(async function () {
      7  const target = await addTabTarget("data:text/html;charset=utf-8,test-doc");
      8  const memory = await target.getFront("memory");
      9 
     10  await memory.attach();
     11 
     12  await memory.startRecordingAllocations();
     13  ok(true, "Can start recording allocations");
     14 
     15  // Allocate some objects.
     16  const [line1, line2, line3] = await SpecialPowers.spawn(
     17    gBrowser.selectedBrowser,
     18    [],
     19    function () {
     20      // Use eval to ensure allocating the object in the page's compartment
     21      return content.eval(
     22        "(" +
     23          function () {
     24            let alloc1, alloc2, alloc3;
     25 
     26            /* eslint-disable max-nested-callbacks */
     27            (function outer() {
     28              (function middle() {
     29                (function inner() {
     30                  alloc1 = {};
     31                  alloc1.line = Error().lineNumber;
     32                  alloc2 = [];
     33                  alloc2.line = Error().lineNumber;
     34                  // eslint-disable-next-line new-parens
     35                  alloc3 = new (function () {})();
     36                  alloc3.line = Error().lineNumber;
     37                })();
     38              })();
     39            })();
     40            /* eslint-enable max-nested-callbacks */
     41 
     42            return [alloc1.line, alloc2.line, alloc3.line];
     43          } +
     44          ")()"
     45      );
     46    }
     47  );
     48 
     49  const response = await memory.getAllocations();
     50 
     51  await memory.stopRecordingAllocations();
     52  ok(true, "Can stop recording allocations");
     53 
     54  // Filter out allocations by library and test code, and get only the
     55  // allocations that occurred in our test case above.
     56 
     57  function isTestAllocation(alloc) {
     58    const frame = response.frames[alloc];
     59    return (
     60      frame &&
     61      frame.functionDisplayName === "inner" &&
     62      (frame.line === line1 || frame.line === line2 || frame.line === line3)
     63    );
     64  }
     65 
     66  const testAllocations = response.allocations.filter(isTestAllocation);
     67  Assert.greaterOrEqual(
     68    testAllocations.length,
     69    3,
     70    "Should find our 3 test allocations (plus some allocations for the error " +
     71      "objects used to get line numbers)"
     72  );
     73 
     74  // For each of the test case's allocations, ensure that the parent frame
     75  // indices are correct. Also test that we did get an allocation at each
     76  // line we expected (rather than a bunch on the first line and none on the
     77  // others, etc).
     78 
     79  const expectedLines = new Set([line1, line2, line3]);
     80  is(expectedLines.size, 3, "We are expecting 3 allocations");
     81 
     82  for (const alloc of testAllocations) {
     83    const innerFrame = response.frames[alloc];
     84    ok(innerFrame, "Should get the inner frame");
     85    is(innerFrame.functionDisplayName, "inner");
     86    expectedLines.delete(innerFrame.line);
     87 
     88    const middleFrame = response.frames[innerFrame.parent];
     89    ok(middleFrame, "Should get the middle frame");
     90    is(middleFrame.functionDisplayName, "middle");
     91 
     92    const outerFrame = response.frames[middleFrame.parent];
     93    ok(outerFrame, "Should get the outer frame");
     94    is(outerFrame.functionDisplayName, "outer");
     95 
     96    // Not going to test the rest of the frames because they are Task.jsm
     97    // and promise frames and it gets gross. Plus, I wouldn't want this test
     98    // to start failing if they changed their implementations in a way that
     99    // added or removed stack frames here.
    100  }
    101 
    102  is(expectedLines.size, 0, "Should have found all the expected lines");
    103 
    104  await memory.detach();
    105 
    106  await target.destroy();
    107 });