PerformanceTests/resources/runner.js

// There are tests for computeStatistics() located in LayoutTests/fast/harness/perftests

// We need access to console.memory for the memory measurements
if (window.internals)
    internals.settings.setMemoryInfoEnabled(true);

if (window.testRunner) {
    testRunner.waitUntilDone();
    testRunner.dumpAsText();
}

(function () {
    var logLines = null;
    var completedRuns = -1;
    var callsPerIteration = 1;
    var currentTest = null;
    var results = [];
    var jsHeapResults = [];
    var mallocHeapResults = [];
    var runCount = undefined;

    var PerfTestRunner = {};

    // To make the benchmark results predictable, we replace Math.random with a
    // 100% deterministic alternative.
    PerfTestRunner.randomSeed = PerfTestRunner.initialRandomSeed = 49734321;

    PerfTestRunner.resetRandomSeed = function() {
        PerfTestRunner.randomSeed = PerfTestRunner.initialRandomSeed
    }

    PerfTestRunner.random = Math.random = function() {
        // Robert Jenkins' 32 bit integer hash function.
        var randomSeed = PerfTestRunner.randomSeed;
        randomSeed = ((randomSeed + 0x7ed55d16) + (randomSeed << 12))  & 0xffffffff;
        randomSeed = ((randomSeed ^ 0xc761c23c) ^ (randomSeed >>> 19)) & 0xffffffff;
        randomSeed = ((randomSeed + 0x165667b1) + (randomSeed << 5))   & 0xffffffff;
        randomSeed = ((randomSeed + 0xd3a2646c) ^ (randomSeed << 9))   & 0xffffffff;
        randomSeed = ((randomSeed + 0xfd7046c5) + (randomSeed << 3))   & 0xffffffff;
        randomSeed = ((randomSeed ^ 0xb55a4f09) ^ (randomSeed >>> 16)) & 0xffffffff;
        PerfTestRunner.randomSeed = randomSeed;
        return (randomSeed & 0xfffffff) / 0x10000000;
    };

    PerfTestRunner.now = window.performance && window.performance.webkitNow ? function () { return window.performance.webkitNow(); } : Date.now;

    PerfTestRunner.logInfo = function (text) {
        if (!window.testRunner)
            this.log(text);
    }

    PerfTestRunner.loadFile = function (path) {
        var xhr = new XMLHttpRequest();
        xhr.open("GET", path, false);
        xhr.send(null);
        return xhr.responseText;
    }

    PerfTestRunner.computeStatistics = function (times, unit) {
        var data = times.slice();

        // Add values from the smallest to the largest to avoid the loss of significance
        data.sort(function(a,b){return a-b;});

        var middle = Math.floor(data.length / 2);
        var result = {
            min: data[0],
            max: data[data.length - 1],
            median: data.length % 2 ? data[middle] : (data[middle - 1] + data[middle]) / 2,
        };

        // Compute the mean and variance using Knuth's online algorithm (has good numerical stability).
        var squareSum = 0;
        result.values = times;
        result.mean = 0;
        for (var i = 0; i < data.length; ++i) {
            var x = data[i];
            var delta = x - result.mean;
            var sweep = i + 1.0;
            result.mean += delta / sweep;
            squareSum += delta * (x - result.mean);
        }
        result.variance = data.length <= 1 ? 0 : squareSum / (data.length - 1);
        result.stdev = Math.sqrt(result.variance);
        result.unit = unit || "ms";

        return result;
    }

    PerfTestRunner.logStatistics = function (values, unit, title) {
        var statistics = this.computeStatistics(values, unit);
        this.printStatistics(statistics, title);
    }

    PerfTestRunner.printStatistics = function (statistics, title) {
        this.log("");
        this.log(title);
        if (statistics.values)
            this.log("values " + statistics.values.join(", ") + " " + statistics.unit);
        this.log("avg " + statistics.mean + " " + statistics.unit);
        this.log("median " + statistics.median + " " + statistics.unit);
        this.log("stdev " + statistics.stdev + " " + statistics.unit);
        this.log("min " + statistics.min + " " + statistics.unit);
        this.log("max " + statistics.max + " " + statistics.unit);
    }

    PerfTestRunner.getUsedMallocHeap = function() {
        var stats = window.internals.mallocStatistics();
        return stats.committedVMBytes - stats.freeListBytes;
    }

    PerfTestRunner.getUsedJSHeap = function() {
        return console.memory.usedJSHeapSize;
    }

    PerfTestRunner.getAndPrintMemoryStatistics = function() {
        if (!window.internals)
            return;
        var jsMemoryStats = PerfTestRunner.computeStatistics([PerfTestRunner.getUsedJSHeap()], "bytes");
        PerfTestRunner.printStatistics(jsMemoryStats, "JS Heap:");

        var mallocMemoryStats = PerfTestRunner.computeStatistics([PerfTestRunner.getUsedMallocHeap()], "bytes");
        PerfTestRunner.printStatistics(mallocMemoryStats, "Malloc:");
    }

    PerfTestRunner.gc = function () {
        if (window.GCController)
            window.GCController.collect();
        else {
            function gcRec(n) {
                if (n < 1)
                    return {};
                var temp = {i: "ab" + i + (i / 100000)};
                temp += "foo";
                gcRec(n-1);
            }
            for (var i = 0; i < 1000; i++)
                gcRec(10);
        }
    };

    function logInDocument(text) {
        if (!document.getElementById("log")) {
            var pre = document.createElement("pre");
            pre.id = "log";
            document.body.appendChild(pre);
        }
        document.getElementById("log").innerHTML += text + "\n";
        window.scrollTo(0, document.body.height);
    }

    PerfTestRunner.log = function (text) {
        if (logLines)
            logLines.push(text);
        else
            logInDocument(text);
    }

    function logFatalError(text) {
        PerfTestRunner.log(text);
        finish();
    }

    function start(test, runner) {
        if (!test) {
            logFatalError("Got a bad test object.");
            return;
        }
        currentTest = test;
        runCount = test.runCount || 20;
        logLines = window.testRunner ? [] : null;
        PerfTestRunner.log("Running " + runCount + " times");
        scheduleNextRun(runner);
    }

    function scheduleNextRun(runner) {
        PerfTestRunner.gc();
        window.setTimeout(function () {
            try {
                var measuredValue = runner();
            } catch (exception) {
                logFatalError("Got an exception while running test.run with name=" + exception.name + ", message=" + exception.message);
                return;
            }

            completedRuns++;

            try {
                ignoreWarmUpAndLog(measuredValue);
            } catch (exception) {
                logFatalError("Got an exception while logging the result with name=" + exception.name + ", message=" + exception.message);
                return;
            }

            if (completedRuns < runCount)
                scheduleNextRun(runner);
            else
                finish();
        }, 0);
    }

    function ignoreWarmUpAndLog(measuredValue) {
        var labeledResult = measuredValue + " " + PerfTestRunner.unit;
        if (completedRuns <= 0)
            PerfTestRunner.log("Ignoring warm-up run (" + labeledResult + ")");
        else {
            results.push(measuredValue);
            if (window.internals) {
                jsHeapResults.push(PerfTestRunner.getUsedJSHeap());
                mallocHeapResults.push(PerfTestRunner.getUsedMallocHeap());
            }
            PerfTestRunner.log(labeledResult);
        }
    }

    function finish() {
        try {
            if (currentTest.description)
                PerfTestRunner.log("Description: " + currentTest.description);
            PerfTestRunner.logStatistics(results, PerfTestRunner.unit, "Time:");
            if (jsHeapResults.length) {
                PerfTestRunner.logStatistics(jsHeapResults, "bytes", "JS Heap:");
                PerfTestRunner.logStatistics(mallocHeapResults, "bytes", "Malloc:");
            }
            if (logLines)
                logLines.forEach(logInDocument);
            if (currentTest.done)
                currentTest.done();
        } catch (exception) {
            logInDocument("Got an exception while finalizing the test with name=" + exception.name + ", message=" + exception.message);
        }

        if (window.testRunner)
            testRunner.notifyDone();
    }

    PerfTestRunner.measureTime = function (test) {
        PerfTestRunner.unit = "ms";
        start(test, measureTimeOnce);
    }

    function measureTimeOnce() {
        var start = PerfTestRunner.now();
        var returnValue = currentTest.run();
        var end = PerfTestRunner.now();

        if (returnValue - 0 === returnValue) {
            if (returnValue <= 0)
                PerfTestRunner.log("runFunction returned a non-positive value: " + returnValue);
            return returnValue;
        }

        return end - start;
    }

    PerfTestRunner.runPerSecond = function (test) {
        PerfTestRunner.unit = "runs/s";
        start(test, measureRunsPerSecondOnce);
    }

    function measureRunsPerSecondOnce() {
        var timeToRun = 750;
        var totalTime = 0;
        var numberOfRuns = 0;

        if (currentTest.setup)
            currentTest.setup();

        while (totalTime < timeToRun) {
            totalTime += callRunAndMeasureTime(callsPerIteration);
            numberOfRuns += callsPerIteration;
            if (completedRuns < 0 && totalTime < 100)
                callsPerIteration = Math.max(10, 2 * callsPerIteration);
        }

        return numberOfRuns * 1000 / totalTime;
    }

    function callRunAndMeasureTime(callsPerIteration) {
        var startTime = PerfTestRunner.now();
        for (var i = 0; i < callsPerIteration; i++)
            currentTest.run();
        return PerfTestRunner.now() - startTime;
    }

    window.PerfTestRunner = PerfTestRunner;
})();