Chrome 开发工具没有显示任何泄漏，但任务管理器会显示直到 chrome 崩溃

Question

So I have this quite CPU-consuming app: https://codepen.io/team/amcharts/pen/47c41af971fe467b8b41f29be7ed1880

It's a Canvas on which things are drawn (a lot).

HTML:

<script src="https://cdn.amcharts.com/lib/5/index.js"></script>
<script src="https://cdn.amcharts.com/lib/5/xy.js"></script>
<script src="https://cdn.amcharts.com/lib/5/themes/Animated.js"></script>
<div id="chartdiv" style="width:100%; height:400px"></div>

JavaScript:

/**
 * ---------------------------------------
 * This demo was created using amCharts 5.
 * 
 * For more information visit:
 * https://www.amcharts.com/
 * 
 * Documentation is available at:
 * https://www.amcharts.com/docs/v5/
 * ---------------------------------------
 */

// Create root element
// https://www.amcharts.com/docs/v5/getting-started/#Root_element
var root = am5.Root.new("chartdiv");


// Set themes
// https://www.amcharts.com/docs/v5/concepts/themes/
root.setThemes([
  am5themes_Animated.new(root)
]);


// Generate random data
var value = 100;

function generateChartData() {
  var chartData = [];
  var firstDate = new Date();
  firstDate.setDate(firstDate.getDate() - 1000);
  firstDate.setHours(0, 0, 0, 0);

  for (var i = 0; i < 50; i++) {
    var newDate = new Date(firstDate);
    newDate.setSeconds(newDate.getSeconds() + i);

    value += (Math.random() < 0.5 ? 1 : -1) * Math.random() * 10;

    chartData.push({
      date: newDate.getTime(),
      value: value
    });
  }
  return chartData;
}

var data = generateChartData();


// Create chart
// https://www.amcharts.com/docs/v5/charts/xy-chart/
var chart = root.container.children.push(am5xy.XYChart.new(root, {
  focusable: true,
  panX: true,
  panY: true,
  wheelX: "panX",
  wheelY: "zoomX",
  scrollbarX:am5.Scrollbar.new(root, {orientation:"horizontal"})
}));

var easing = am5.ease.linear;


// Create axes
// https://www.amcharts.com/docs/v5/charts/xy-chart/axes/
var xAxis = chart.xAxes.push(am5xy.DateAxis.new(root, {
  maxDeviation: 0.5,
  groupData: false,
  extraMax:0.1, // this adds some space in front
  extraMin:-0.1,  // this removes some space form th beginning so that the line would not be cut off
  baseInterval: {
    timeUnit: "second",
    count: 1
  },
  renderer: am5xy.AxisRendererX.new(root, {
    minGridDistance: 50
  }),
  tooltip: am5.Tooltip.new(root, {})
}));

var yAxis = chart.yAxes.push(am5xy.ValueAxis.new(root, {
  renderer: am5xy.AxisRendererY.new(root, {})
}));


// Add series
// https://www.amcharts.com/docs/v5/charts/xy-chart/series/
var series = chart.series.push(am5xy.ColumnSeries.new(root, {
  name: "Series 1",
  xAxis: xAxis,
  yAxis: yAxis,
  valueYField: "value",
  valueXField: "date",
  tooltip: am5.Tooltip.new(root, {
    pointerOrientation: "horizontal",
    labelText: "{valueY}"
  })
}));

series.data.setAll(data);

// Add cursor
// https://www.amcharts.com/docs/v5/charts/xy-chart/cursor/
var cursor = chart.set("cursor", am5xy.XYCursor.new(root, {
  xAxis: xAxis
}));
cursor.lineY.set("visible", false);


// Update data every second
setInterval(function () {
  addData();
}, 100)


function addData() {
  var lastDataItem = series.dataItems[series.dataItems.length - 1];

  var lastValue = lastDataItem.get("valueY");
  var newValue = value + ((Math.random() < 0.5 ? 1 : -1) * Math.random() * 5);
  var lastDate = new Date(lastDataItem.get("valueX"));
  var time = am5.time.add(new Date(lastDate), "second", 1).getTime();
  series.data.removeIndex(0);
  series.data.push({
    date: time,
    value: newValue
  })

  var newDataItem = series.dataItems[series.dataItems.length - 1];
  newDataItem.animate({
    key: "valueYWorking",
    to: newValue,
    from: lastValue,
    duration: 600,
    easing: easing
  });

  var animation = newDataItem.animate({
    key: "locationX",
    to: 0.5,
    from: -0.5,
    duration: 600
  });
  if (animation) {
    var tooltip = xAxis.get("tooltip");
    if (tooltip && !tooltip.isHidden()) {
      animation.events.on("stopped", function () {
        xAxis.updateTooltip();
      })
    }
  }
}

setTimeout(function(){
  xAxis.zoom(0.5, 1)
}, 1500)

After some time of running it, all Chromium browsers crash. Even though Dev tools does not show any memory leak - number of listeners, nodes and heap size remains the same (the heap might increase a bit initially but then stabilizes). But the task manager shows memory growing. Important thing - the browser window must be focused. The strange thing is that if I zoom-out the chart using scrollbar or resize window or close and open the tab, the memory could drop to a normal level. This thing happens both with dev tools opened and closed.

This does not happen on Firefox, so I believe it's some browser issue. Appreciate for any insights.

Answer 1

So we found out that this is indeed a Chromium issue, calling setTransform on a context (if nothing else is done) results to leak (which is not visible when profiling) and a crash. We reported it as a bug and hopefully it will be fixed. Meanwhile we are working on a workaround to avoid this situation.

var canvas = document.createElement('canvas');
document.body.appendChild(canvas);

var context = canvas.getContext('2d');

function loop() {
  requestAnimationFrame(() => {
    loop();

    for (var j = 0; j < 10000; ++j) {
      context.setTransform(0.5, 1, 1, 0.5, 1, 1);
    }
  });
}

loop();