tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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Memory-takeCensus-09.js (2691B)

      1 // Debugger.Memory.prototype.takeCensus: by: allocationStack breakdown
      2 
      3 var g = newGlobal({newCompartment: true});
      4 var dbg = new Debugger(g);
      5 
      6 g.evaluate(`
      7           var log = [];
      8           function f() { log.push(allocationMarker()); }
      9           function g() { f(); }
     10           function h() { f(); }
     11           `,
     12           { fileName: "Rockford", lineNumber: 1000 });
     13 
     14 // Create one allocationMarker with tracking turned off,
     15 // so it will have no associated stack.
     16 g.f();
     17 
     18 dbg.memory.allocationSamplingProbability = 1;
     19 dbg.memory.trackingAllocationSites = true;
     20 
     21 for ([f, n] of [[g.f, 20], [g.g, 10], [g.h, 5]])
     22  for (let i = 0; i < n; i++)
     23    f();  // all allocations of allocationMarker occur with this line as the
     24          // oldest stack frame.
     25 
     26 let census = dbg.memory.takeCensus({ breakdown: { by: 'objectClass',
     27                                                  then: { by: 'allocationStack',
     28                                                          then: { by: 'count',
     29                                                                  label: 'haz stack'
     30                                                                },
     31                                                          noStack: { by: 'count',
     32                                                                     label: 'no haz stack'
     33                                                                   }
     34                                                        }
     35                                                }
     36                                   });
     37 
     38 let map = census.AllocationMarker;
     39 assertEq(map instanceof Map, true);
     40 
     41 // Gather the stacks we are expecting to appear as keys, and
     42 // check that there are no unexpected keys.
     43 let stacks = { };
     44 
     45 map.forEach((v, k) => {
     46  if (k === 'noStack') {
     47    // No need to save this key.
     48  } else if (k.functionDisplayName === 'f' &&
     49             k.parent.functionDisplayName === null) {
     50    stacks.f = k;
     51  } else if (k.functionDisplayName === 'f' &&
     52             k.parent.functionDisplayName === 'g' &&
     53             k.parent.parent.functionDisplayName === null) {
     54    stacks.fg = k;
     55  } else if (k.functionDisplayName === 'f' &&
     56             k.parent.functionDisplayName === 'h' &&
     57             k.parent.parent.functionDisplayName === null) {
     58    stacks.fh = k;
     59  } else {
     60    assertEq(true, false);
     61  }
     62 });
     63 
     64 assertEq(map.get('noStack').label, 'no haz stack');
     65 assertEq(map.get('noStack').count, 1);
     66 
     67 assertEq(map.get(stacks.f).label, 'haz stack');
     68 assertEq(map.get(stacks.f).count, 20);
     69 
     70 assertEq(map.get(stacks.fg).label, 'haz stack');
     71 assertEq(map.get(stacks.fg).count, 10);
     72 
     73 assertEq(map.get(stacks.fh).label, 'haz stack');
     74 assertEq(map.get(stacks.fh).count, 5);