generator-telemetry.js

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// |jit-test| skip-if: !getJitCompilerOptions()['ion.enable']; --ion-eager

// Test the telemetry added in Bug 1944683.

// The nested loop satisfies YieldAnalyzer (js/src/jit/BytecodeAnalysis.cpp)

// which only allows Ion compilation of a yielding loop when it contains an

// inner loop or sufficient bytecode.

function* gen() {

  for (let i = 0; i < 1; i++) {

    for (let j = 0; j < 0; j++) {}

    yield i;

async function* asyncGen() {

  for (let i = 0; i < 1; i++) {

    for (let j = 0; j < 0; j++) {}

    yield i;

let useCounters = getUseCounterResults();

assertEq(useCounters.GeneratorFunctionCreated, 0);

assertEq(useCounters.AsyncGeneratorFunctionCreated, 0);

assertEq(useCounters.GeneratorFunctionIonEligible, 0);

assertEq(useCounters.AsyncGeneratorFunctionIonEligible, 0);

gen();

asyncGen();

useCounters = getUseCounterResults();

assertEq(useCounters.GeneratorFunctionCreated, 1);

assertEq(useCounters.AsyncGeneratorFunctionCreated, 1);

gen();

useCounters = getUseCounterResults();

assertEq(useCounters.GeneratorFunctionCreated, 2);

assertEq(useCounters.AsyncGeneratorFunctionCreated, 1);

const GeneratorFunction = function*(){}.constructor;

const AsyncGeneratorFunction = async function*(){}.constructor;

GeneratorFunction("yield 1;")();

AsyncGeneratorFunction("yield 1;")();

useCounters = getUseCounterResults();

assertEq(useCounters.GeneratorFunctionCreated, 3);

assertEq(useCounters.AsyncGeneratorFunctionCreated, 2);

for (let i = 0; i < 10; i++) {

  gen().next();

useCounters = getUseCounterResults();

// Use-counters deduplicate per-document in product code, so we only

// check that the counter has fired.

assertEq(useCounters.GeneratorFunctionIonEligible >= 1, true);

for (let i = 0; i < 10; i++) {

  asyncGen().next();

useCounters = getUseCounterResults();

assertEq(useCounters.AsyncGeneratorFunctionIonEligible >= 1, true);