Memory-allocationSamplingProbability-02.js

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// Test that we only sample about allocationSamplingProbability * 100 percent of

// allocations.

const root = newGlobal({newCompartment: true});

const dbg = new Debugger();

const wrappedRoot = dbg.addDebuggee(root);

root.eval(`

  objs = [];

  objs.push(new Object);

`);

root.eval("" + function makeSomeAllocations() {

  for (var i = 0; i < 100; i++) {

    objs.push(new Object);

});

function measure(P, expected) {

  root.setSavedStacksRNGState(Number.MAX_SAFE_INTEGER - 1);

  dbg.memory.allocationSamplingProbability = P;

  root.makeSomeAllocations();

  assertEq(dbg.memory.drainAllocationsLog().length, expected);

dbg.memory.trackingAllocationSites = true;

// These are the sample counts that were correct when this test was last

// updated; changes to SpiderMonkey may occasionally cause changes

// here. Anything that is within a plausible range for the given sampling

// probability is fine.

measure(0.0, 0);

measure(1.0, 100);

measure(0.1, 11);

measure(0.5, 49);